Voice over IP - Knowledge (XXG)

1645:. The issue in question is calls between Americans and foreigners. The NSA is not authorized to tap Americans' conversations without a warrant—but the Internet, and specifically VoIP does not draw as clear a line to the location of a caller or a call's recipient as the traditional phone system does. As VoIP's low cost and flexibility convinces more and more organizations to adopt the technology, surveillance for law enforcement agencies becomes more difficult. VoIP technology has also increased federal security concerns because VoIP and similar technologies have made it more difficult for the government to determine where a target is physically located when communications are being intercepted, and that creates a whole set of new legal challenges. 1589:(USFK) members residing on USFK bases threatened to block off access to VoIP services used by USFK members as an economical way to keep in contact with their families in the United States, on the grounds that the service members' VoIP providers were not registered. A compromise was reached between USFK and Korean telecommunications officials in January 2007, wherein USFK service members arriving in Korea before June 1, 2007, and subscribing to the ISP services provided on base could continue to use their US-based VoIP subscription, but later arrivals are required to use a Korean-based VoIP provider, which by contract will offer pricing similar to the flat rates offered by US VoIP providers. 1044:(LCR) challenges to reach its destination if the number is routed to a mobile phone number on a traditional mobile carrier. LCR is based on checking the destination of each telephone call as it is made, and then sending the call via the network that will cost the customer the least. This rating is subject to some debate given the complexity of call routing created by number portability. With MNP in place, LCR providers can no longer rely on using the network root prefix to determine how to route a call. Instead, they must now determine the actual network of every number before routing the call. 1033:(MNP) also impact VoIP business. Number portability is a service that allows a subscriber to select a new telephone carrier without requiring a new number to be issued. Typically, it is the responsibility of the former carrier to "map" the old number to the undisclosed number assigned by the new carrier. This is achieved by maintaining a database of numbers. A dialed number is initially received by the original carrier and quickly rerouted to the new carrier. Multiple porting references must be maintained even if the subscriber returns to the original carrier. The 1444:, the treatment of VoIP service providers is a decision for each national telecommunications regulator, which must use competition law to define relevant national markets and then determine whether any service provider on those national markets has "significant market power" (and so should be subject to certain obligations). A general distinction is usually made between VoIP services that function over managed networks (via broadband connections) and VoIP services that function over unmanaged networks (essentially, the Internet). 798:(VCI) for voice over IP has the potential to reduce latency on shared connections. ATM's potential for latency reduction is greatest on slow links because worst-case latency decreases with increasing link speed. A full-size (1500 byte) Ethernet frame takes 94 ms to transmit at 128 kbit/s but only 8 ms at 1.5 Mbit/s. If this is the bottleneck link, this latency is probably small enough to ensure good VoIP performance without MTU reductions or multiple ATM VCs. The latest generations of DSL, 590: 775:(MOS) and R factors and configuration information related to the jitter buffer. VoIP metrics reports are exchanged between IP endpoints on an occasional basis during a call, and an end of call message sent via SIP RTCP summary report or one of the other signaling protocol extensions. VoIP metrics reports are intended to support real-time feedback related to QoS problems, the exchange of information between the endpoints for improved call quality calculation and a variety of other applications. 5806: 1363: 5330: 5316: 6877: 1278:. Though many consumer VoIP solutions do not support encryption of the signaling path or the media, securing a VoIP phone is conceptually easier to implement using VoIP than on traditional telephone circuits. A result of the lack of widespread support for encryption is that it is relatively easy to eavesdrop on VoIP calls when access to the data network is possible. Free open-source solutions, such as 920: 6887: 1468:, it is illegal to provide or use unauthorized VoIP services, to the extent that web sites of unlicensed VoIP providers have been blocked. Violations may be punished with fines of 50,000 Omani Rial (about 130,317 US dollars), a two-year prison sentence or both. In 2009, police raided 121 Internet cafes throughout the country and arrested 212 people for using or providing VoIP services. 6866: 5796: 728:. This suggests continually estimating the mean delay and its standard deviation and setting the playout delay so that only packets delayed more than several standard deviations above the mean will arrive too late to be useful. In practice, the variance in latency of many Internet paths is dominated by a small number (often one) of relatively slow and congested 6897: 1581:, only providers registered with the government are authorized to offer VoIP services. Unlike many VoIP providers, most of whom offer flat rates, Korean VoIP services are generally metered and charged at rates similar to terrestrial calling. Foreign VoIP providers encounter high barriers to government registration. This issue came to a head in 2006 when 1103:. The VoIP E911 emergency-calling system associates a physical address with the calling party's telephone number. All VoIP providers that provide access to the public switched telephone network are required to implement E911, a service for which the subscriber may be charged. "VoIP providers may not allow customers to opt-out of 911 service." The 609:

bare metal infrastructure or IoT devices. With some solutions, such as 3CX, companies can attempt to blend the benefits of hosted and private on-premises systems by implementing their own private solution but within an external environment. Examples can include data center collocation services, public cloud, or private cloud locations.

1408:, where the government is nationalizing telecommunication service, it is a criminal offense to offer services using VoIP. The country has installed firewalls to prevent international calls from being made using VoIP. These measures were taken after the popularity of VoIP reduced the income generated by the state-owned 517:. Rather than closed architectures, these devices rely on standard interfaces. VoIP devices have simple, intuitive user interfaces, so users can often make simple system configuration changes. Dual-mode phones enable users to continue their conversations as they move between an outside cellular service and an internal 197:, built closed networks for private user bases, offering the benefit of free calls and convenience while potentially charging for access to other communication networks, such as the PSTN. This limited the freedom of users to mix-and-match third-party hardware and software. Third-generation providers, such as 1092:(ITSP) knows only that a particular user's equipment is active. Service providers often provide emergency response services by agreement with the user who registers a physical location and agrees that, if an emergency number is called from the IP device, emergency services are provided to that address only. 1285:

Government and military organizations use various security measures to protect VoIP traffic, such as voice over secure IP (VoSIP), secure voice over IP (SVoIP), and secure voice over secure IP (SVoSIP). The distinction lies in whether encryption is applied in the telephone endpoint or in the network.

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Softswitch) works in cooperation with a media gateway (aka IP Business Gateway) and connects the digital media stream, so as to complete the path for voice and data. Gateways include interfaces for connecting to standard PSTN networks. Ethernet interfaces are also included in the modern systems which

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In the case of a private VoIP system, the primary telephony system itself is located within the private infrastructure of the end-user organization. Usually, the system will be deployed on-premises at a site within the direct control of the organization. This can provide numerous benefits in terms of

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VoIP endpoints usually have to wait for the completion of transmission of previous packets before new data may be sent. Although it is possible to preempt (abort) a less important packet in mid-transmission, this is not commonly done, especially on high-speed links where transmission times are short

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Therefore, VoIP solutions also need to handle MNP when routing a voice call. In countries without a central database, like the UK, it may be necessary to query the mobile network about which home network a mobile phone number belongs to. As the popularity of VoIP increases in the enterprise markets

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has a direct relationship between a telephone number and a physical location, which is maintained by the telephone company and available to emergency responders via the national emergency response service centers in form of emergency subscriber lists. When an emergency call is received by a center

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In general, the provision of VoIP telephony systems to organizational or individual users can be divided into two primary delivery methods: private or on-premises solutions, or externally hosted solutions delivered by third-party providers. On-premises delivery methods are more akin to the classic

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not TCP because recovering from congestion through retransmission usually entails too much latency. So QoS mechanisms can avoid the undesirable loss of VoIP packets by immediately transmitting them ahead of any queued bulk traffic on the same link, even when the link is congested by bulk traffic.

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Private VoIP systems can be physical hardware PBX appliances, converged with other infrastructure, or they can be deployed as software applications. Generally, the latter two options will be in the form of a separate virtualized appliance. However, in some scenarios, these systems are deployed on

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service without special request, provide for customer location updates, clearly disclose any limitations on their E-911 functionality to their consumers, obtain affirmative acknowledgements of these disclosures from all consumers, and may not allow their customers to opt-out of 911 service. VoIP

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or locally generated power. Some VoIP service providers use customer premises equipment (e.g., cable modems) with battery-backed power supplies to assure uninterrupted service for up to several hours in case of local power failures. Such battery-backed devices typically are designed for use with

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which provide direct current to power most basic analog handsets independently of locally available electrical power. The susceptibility of phone service to power failures is a common problem even with traditional analog service where customers purchase telephone units that operate with wireless

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systems; a circuit switched system of insufficient capacity will refuse new connections while carrying the remainder without impairment, while the quality of real-time data such as telephone conversations on packet-switched networks degrades dramatically. Therefore, VoIP implementations may face

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announces and launches its desktop conferencing product Communique, which includes VoIP and video. The company is credited with developing the first generation of commercial, US-based VoIP, Internet media streaming and real-time Internet telephony/collaborative software and standards that would

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may appear as part of an upstream IP PBX. On mobile devices, e.g., a 3G handset or USB wireless broadband adapter, the IP address has no relationship with any physical location known to the telephony service provider, since a mobile user could be anywhere in a region with network coverage, even

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services that treat all communications—phone calls, faxes, voice mail, e-mail, web conferences, and more—as discrete units that can all be delivered via any means and to any handset, including cellphones. Two kinds of service providers are operating in this space: one set is focused on VoIP for

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Communication on the IP network is perceived as less reliable in contrast to the circuit-switched public telephone network because it does not provide a network-based mechanism to ensure that data packets are not lost, and are delivered in sequential order. It is a best-effort network without

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In India no Separate Numbering Scheme is provided to the Internet Telephony. Presently the 10 digit Numbering allocation based on E.164 is permitted to the Fixed Telephony, GSM, CDMA wireless service. For Internet Telephony, the numbering scheme shall only conform to IP addressing Scheme of

1805:(SIP) gained widespread attention. In the early 2000s, the proliferation of high-bandwidth always-on Internet connections to residential dwellings and businesses, spawned an industry of Internet telephony service providers (ITSPs). The development of open-source telephony software, such as 770:

is generated by an VoIP phone or gateway during a live call and contains information on packet loss rate, packet discard rate (because of jitter), packet loss/discard burst metrics (burst length/density, gap length/density), network delay, end system delay, signal/noise/echo level,

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The relevant EU Directive is not clearly drafted concerning obligations that can exist independently of market power (e.g., the obligation to offer access to emergency calls), and it is impossible to say definitively whether VoIP service providers of either type are bound by them.

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By default, network routers handle traffic on a first-come, first-served basis. Fixed delays cannot be controlled as they are caused by the physical distance the packets travel. They are especially problematic when satellite circuits are involved because of the long distance to a

605:), cost scalability, and ensuring privacy and security of communications traffic. However, the responsibility for ensuring that the VoIP system remains performant and resilient is predominantly vested in the end-user organization. This is not the case with a Hosted VoIP solution. 2432:

Voice over IP (VOIP) uses the Internet Protocol (IP) to transmit voice as packets over an IP network. ...in the Internet, anyone can capture the packets meant for someone else. Some security can be provided by using encryption and tunneling. The common tunneling protocol used is

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Endpoints, such as VoIP telephones or softphone applications (apps running on a computer or mobile device), will connect to the VoIP service remotely. These connections typically take place over public internet links, such as local fixed WAN breakout or mobile carrier service.

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protocol. The T.38 protocol is designed to compensate for the differences between traditional packet-less communications over analog lines and packet-based transmissions which are the basis for IP communications. The fax machine may be a standard device connected to an

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attacks, harvest customer data, record conversations, and compromise voicemail messages. Compromised VoIP user account or session credentials may enable an attacker to incur substantial charges from third-party services, such as long-distance or international calling.

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Some newer high-end fax machines have built-in T.38 capabilities which are connected directly to a network switch or router. In T.38 each packet contains a portion of the data stream sent in the previous packet. Two successive packets have to be lost to actually lose

338:, one of the first VoIP call signaling and control protocols that found widespread implementation. Since the development of newer, less complex protocols such as MGCP and SIP, H.323 deployments are increasingly limited to carrying existing long-haul network traffic. 623:, private networks such as MPLS and SD-WAN, or via private SBCs (Session Border Controllers). While exceptions and private peering options do exist, it is generally uncommon for those private connectivity methods to be provided by Hosted or Cloud VoIP providers. 1037:(FCC) mandates carrier compliance with these consumer-protection stipulations. In November 2007, the FCC in the United States released an order extending number portability obligations to interconnected VoIP providers and carriers that support VoIP providers. 512:

VoIP allows both voice and data communications to be run over a single network, which can significantly reduce infrastructure costs. The prices of extensions on VoIP are lower than for PBX and key systems. VoIP switches may run on commodity hardware, such as

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ATM has substantial header overhead: 5/53 = 9.4%, roughly twice the total header overhead of a 1500 byte Ethernet frame. This "ATM tax" is incurred by every DSL user whether or not they take advantage of multiple virtual circuits – and few can.

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for commercial traffic, IP telephony was tested and deemed infeasible for commercial use until the introduction of VocalChat in the early 1990s and then in Feb 1995 the official release of Internet Phone (or iPhone for short) commercial software by

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application software installed on a networked computer that is equipped with a microphone and speaker, or headset. The application typically presents a dial pad and display field to the user to operate the application by mouse clicks or keyboard

535:, which originally marketed itself as a service among friends, has begun to cater to businesses, providing free-of-charge connections between any users on the Skype network and connecting to and from ordinary PSTN telephones for a charge. 421: 1176:

analog handsets. Some VoIP service providers implement services to route calls to other telephone services of the subscriber, such a cellular phone, in the event that the customer's network device is inaccessible to terminate the call.

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In the two decades following the 1974 demo, various forms of packet telephony were developed and industry interest groups formed to support the new technologies. Following the termination of the ARPANET project, and expansion of the

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Because of the bandwidth efficiency and low costs that VoIP technology can provide, businesses are migrating from traditional copper-wire telephone systems to VoIP systems to reduce their monthly phone costs. In 2008, 80% of all new

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In the United States, the FCC requires all interconnected VoIP service providers to comply with requirements comparable to those for traditional telecommunications service providers. VoIP operators in the US are required to support

1789:, and followed by other VoIP infrastructure components such as telephony gateways and switching servers. Soon after it became an established area of interest in commercial labs of the major IT concerns, notably at AT&T, where 1064:

In IP telephony, no such direct link between location and communications end point exists. Even a provider having wired infrastructure, such as a DSL provider, may know only the approximate location of the device, based on the

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Although jitter is a random variable, it is the sum of several other random variables that are at least somewhat independent: the individual queuing delays of the routers along the Internet path in question. Motivated by the

436:. Many offer unlimited domestic calling and sometimes international calls for a flat monthly subscription fee. Phone calls between subscribers of the same provider are usually free when flat-fee service is not available. 4574: 1536:

inside India. This effectively means that people who have PCs can use them to make a VoIP call to other computers but not to a normal phone number. Foreign-based VoIP server services are illegal to use in India.

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and other researchers were motivated by a desire for a higher degree of circuit redundancy and network availability in the face of infrastructure failures than was possible in the circuit-switched networks in

308:– Implementing access control, verifying the identity of other participants (computers or people), and encrypting data to protect the privacy and integrity of the media contents and/or the control messages. 1496:

were allowed. In January 2018, internet service providers in UAE blocked all VoIP apps, including Skype, but permitting only 2 government-approved VoIP apps (C’ME and BOTIM). In opposition, a petition on

636:(QoS) guarantees. Voice, and all other data, travels in packets over IP networks with fixed maximum capacity. This system may be more prone to data loss in the presence of congestion than traditional 1568:

The Internet Service Licensee is not permitted to have PSTN/PLMN connectivity. Voice communication to and from a telephone connected to PSTN/PLMN and following E.164 numbering is prohibited in India.

1139:(ATA), or it may be a software application or dedicated network device operating via an Ethernet interface. Originally, T.38 was designed to use UDP or TCP transmission methods across an IP network. 1349:

VoIP has drastically reduced the cost of communication by sharing network infrastructure between data and voice. A single broadband connection has the ability to transmit multiple telephone calls.

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A variety of functions are needed to implement VoIP communication. Some protocols perform multiple functions, while others perform only a few and must be used in concert. These functions include:

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Early providers of voice-over-IP services used business models and offered technical solutions that mirrored the architecture of the legacy telephone network. Second-generation providers, such as

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released in August 2003. This was the creation of Niklas Zennström and Janus Friis, in cooperation with four Estonian developers. It quickly became a popular program that helped democratize VoIP.

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Any device / Adapter conforming to standards of International agencies like ITU, IETF etc. connected to ISP node with static IP address to similar device / Adapter; within or outside India.

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connects to the network and implements the electronics and firmware to operate a conventional analog telephone attached through a modular phone jack. Some residential Internet gateways and

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over VoIP networks is sometimes referred to as Fax over IP (FoIP). Transmission of fax documents was problematic in early VoIP implementations, as most voice digitization and compression

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The quality of voice transmission is characterized by several metrics that may be monitored by network elements and by the user agent hardware or software. Such metrics include network

432:, by which subscribers place and receive telephone calls in much the same manner as they would via the PSTN. Full-service VoIP phone companies provide inbound and outbound service with 881:). G.hn provides QoS by means of Contention-Free Transmission Opportunities (CFTXOPs) which are allocated to flows (such as a VoIP call) that require QoS and which have negotiated a 276:– Performing registration (advertising one's presence and contact information) and discovery (locating someone and obtaining their contact information), dialing (including reporting 5041: 704:

along a given network path due to competition from other users for the same transmission links. VoIP receivers accommodate this variation by storing incoming packets briefly in a

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vom Treffen der IETF-Codec-Arbeitsgruppe auf der Konferenz IETF79 in Peking, China mit einer Darstellung der grundlegenden Funktionsprinzipien durch Koen Vos (MP3, ~70 MiB)

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Wireline telephones which are manufactured in, imported to, or intended to be used in the US with Voice over IP service, on or after February 28, 2020, are required to meet the

3191: 1565:(IANA). Translation of E.164 number / private number to IP address allotted to any device and vice versa, by ISP to show compliance with IANA numbering scheme is not permitted. 664:

Network routers on high volume traffic links may introduce latency that exceeds permissible thresholds for VoIP. Excessive load on a link can cause congestion and associated

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with geographic relevance to the end-user(s) of the system. This infrastructure is external to the user of the system and is deployed and maintained by the service provider.

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VoIP solutions. Hosted systems are also generally better suited to smaller or personal use VoIP deployments, where a private system may not be viable for these scenarios.

2780: 1853: 1607: 1007:. Often VoIP implementations employ methods of translating non-E.164 identifiers to E.164 numbers and vice versa, such as the Skype-In service provided by Skype and the 991:

to allow calls to be routed to and from VoIP subscribers and the PSTN/PLMN. VoIP implementations can also allow other identification techniques to be used. For example,

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are optimized for the representation of the human voice and the proper timing of the modem signals cannot be guaranteed in a packet-based, connectionless network.

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RADVision and Intel Target Compatibility Between RADVision's H.323/320 Videoconferencing Gateway And Intel's Business Video Conferencing And TeamStation Products.

5354: 3726: 1100: 4269: 4222: 791:(AAL5) to segment each Ethernet packet into a series of 53-byte ATM cells for transmission, reassembling them back into Ethernet frames at the receiving end. 521:

network, so that it is no longer necessary to carry both a desktop phone and a cell phone. Maintenance becomes simpler as there are fewer devices to oversee.

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VoIP solutions involve a service provider or telecommunications carrier hosting the telephone system as a software solution within their own infrastructure.

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remained blocked from being used for voice and video calls, constricting residents to use paid services from the country's state-owned telecom providers.

4257: 391: 258:– Creating reliable transmission over unreliable protocols, which may involve acknowledging receipt of data and retransmitting data that wasn't received. 3569: 3250:"RFC 3969– The Internet Assigned Number Authority (IANA) Uniform Resource Identifier (URI) Parameter Registry for the Session Initiation Protocol (SIP)" 1492:(UAE), it is illegal to provide or use unauthorized VoIP services. Web sites of unlicensed VoIP providers have been blocked. Some VoIP services such as 509:

is converting its field offices of 63,000 workers from traditional phone installations to a VoIP infrastructure carried over its existing data network.

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of a corporate entity, in which case the IP address being used for customer communications may belong to the enterprise, not the residential ISP. Such

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On March 24, 2020, the United Arab Emirates loosened restriction on VoIP services earlier prohibited in the country, to ease communication during the

1309:(NSA) released comprehensive documents describing the four attack planes of a communications system – the network, perimeter, session controllers and 1069:

allocated to the network router and the known service address. Some ISPs do not track the automatic assignment of IP addresses to customer equipment.

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and back; delays of 400–600 ms are typical. Latency can be minimized by marking voice packets as being delay-sensitive with QoS methods such as

5347: 3654: 4062: 3169: 205:. These solutions typically allow dynamic interconnection between users in any two domains of the Internet, when a user wishes to place a call. 6843: 5040:

Schnell, Markus; Schmidt, Markus; Jander, Manuel; Albert, Tobias; Geiger, Ralf; Ruoppila, Vesa; Ekstrand, Per; Bernhard, Grill (October 2008).

4115: 1244: 286:– Determining what type of media to send (audio, video, etc.), how to encode/decode it, and how to send/receive it (IP addresses, ports, etc.). 4815: 4167: 1192:

connection over traditional phone lines, such as digitizing and digital transmission, are already in place with VoIP. It is necessary only to

6838: 6828: 6808: 6610: 5086: 4192: 3687: 3326: 2215: 1642: 4228:. New Delhi India: Telecom Regulatory Authority of India (TRAI). p. 16 (Section 2.2.1.2 PC–to–Phone Internet telephony). Archived from 111:. Various codecs exist that optimize the media stream based on application requirements and network bandwidth; some implementations rely on 2411: 619:

However, VoIP traffic to and from the on-premises systems can often also be sent over secure private links. Examples include personal VPN,

359: 4663: 4633: 4317: 3924: 3026: 268:(sometimes glossed as simply a "call"), which is a connection between two or more peers that provides a context for further communication. 5254: 4223:"Telecom Regulatory Authority of India (TRAI) Consultation paper on Issues related to Internet Telephony. Consultation Paper No. 11/2008" 2147:

2007: VoIP device manufacturers and sellers boom in Asia, specifically in the Philippines where many families of overseas workers reside.

6833: 6679: 5690: 5590: 3799: 1562: 1302:. Public Secure VoIP is also available with free GNU software and in many popular commercial VoIP programs via libraries, such as ZRTP. 1287: 1271: 1251: 1185: 1089: 365: 5265: 5160: 4379: 1909:

of the Defense Advanced Research Projects Agency (DARPA), agree to separate IP from TCP, and create UDP for carrying real-time traffic.

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PC / a device / Adapter conforming to the standard of any international agencies like- ITU or IETF etc. in India to PSTN/PLMN abroad.

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begins development of standards for the transmission and signaling of voice communications over Internet Protocol networks with the

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support that is compatible with the PSTN. Many VoIP service providers also allow callers to configure custom caller ID information.

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The receiver must resequence IP packets that arrive out of order and recover gracefully when packets arrive too late or not at all.

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As the popularity of VoIP grows, governments are becoming more interested in regulating VoIP in a manner similar to PSTN services.

350:, control protocol for media gateways across a converged internetwork consisting of the traditional PSTN and modern packet networks 212:, VoIP is also available on many personal computers and other Internet access devices. Calls and SMS text messages may be sent via 3839: 3005: 95:

and involve signaling, channel setup, digitization of the analog voice signals, and encoding. Instead of being transmitted over a

6936: 6484: 6032: 5834: 5685: 3756: 3613: 2670: 2060: 1809:, fueled widespread interest and entrepreneurship in voice-over-IP services, applying new Internet technology paradigms, such as 1627: 3545: 3342: 1634:

VoIP service—those who are unable to determine the location of their users—are exempt from state telecommunications regulation.

849:(MAC) layer. The standard is considered of critical importance for delay-sensitive applications, such as voice over wireless IP. 280:), negotiating capabilities, and call control (such as hold, mute, transfer/forwarding, dialing DTMF keys during a call , etc.). 6595: 5370: 2836: 2784: 547:

While many use cases still remain for private or on-premises VoIP systems, the wider market has been gradually shifting toward

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or other methods, the VoIP E911 information is accurate only if subscribers keep their emergency address information current.

6590: 6141: 5710: 3546:"Internet Protocol Telephony & Voice over Internet Protocol Security Technical Implementation Guide Version 2, Release 2" 1931: 1902: 1835: 1753: 1733: 941: 937: 506: 341: 272: 5227: 2753: 1107:

system is based on a static table lookup. Unlike in cellular phones, where the location of an E911 call can be traced using

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medium (e.g. optical fiber) and the routers driving them do not have enough buffering for queuing delays to be significant.

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It is increasingly common for telecommunications providers to use VoIP telephony over dedicated and public IP networks as a

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kbps, leading to the first successful real-time conversation over ARPANET in 1974, between Culler-Harrison Incorporated in

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contributions, and other mandated payments; and enable law enforcement authorities to conduct surveillance pursuant to the

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The security concerns for VoIP telephone systems are similar to those of other Internet-connected devices. This means that

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IP communication provides for device mobility. For example, a residential broadband connection may be used as a link to a

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standard that defines a set of quality-of-service enhancements for wireless LAN applications through modifications to the

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regulates telephone service, including VoIP telephony service. VoIP services operating in Canada are required to provide

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handsets to a base station, or that have other modern phone features, such as built-in voicemail or phone book features.

693:. But since every packet must contain protocol headers, this increases relative header overhead on every link traversed. 6890: 6651: 6548: 6091: 5858: 5406: 4846:"H.323 Visual telephone systems and equipment for local area networks which provide a non-guaranteed quality of service" 4470:"A History of Realtime Digital Speech on Packet Networks: Part II of Linear Predictive Coding and the Internet Protocol" 2938: 371: 353: 4571:

M. R. Schroeder and B. S. Atal, "Code-excited linear prediction (CELP): high-quality speech at very low bit rates," in

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to connect switching centers and to interconnect with other telephony network providers; this is often referred to as

329: 80: 3734: 4275: 4229: 3639: 616:. For remote and external endpoints, available connectivity options mirror those of Hosted or Cloud VoIP solutions. 6739: 6661: 6600: 6307: 3467: 2434: 1586: 1582: 1228: 984: 795: 784: 265: 930: 6941: 6511: 6472: 6317: 6217: 6146: 6079: 5906: 5680: 5416: 5287: 5056: 5019: 4544: 2082: 1232: 1201: 1030: 708:, deliberately increasing latency to improve the chance that each packet will be on hand when it is time for the 690: 429: 3996: 3956: 6870: 6112: 6047: 6000: 5886: 5800: 5675: 5476: 1891: 1823: 1749: 1714: 1599: 1453: 1306: 1275: 1259: 1136: 1026: 973: 874: 725: 713: 654: 455: 131: 96: 4088: 3925:"The Road to Broadband Development in Developing Countries is through Competition Driven by Wireless and VOIP" 3087: 2810: 220:

network. VoIP provides a framework for consolidation of all modern communications technologies using a single

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operators also receive the benefit of certain US telecommunications regulations, including an entitlement to

6931: 6709: 6694: 6538: 6489: 6412: 6312: 5990: 5876: 5871: 5670: 5583: 5429: 2245: 2225: 2075: 1073: 732:. Most Internet backbone links are now so fast (e.g. 10 Gbit/s) that their delays are dominated by the 686: 502: 381: 100: 4946: 3520: 906:(delay), post-dial delay, and echo. The metrics are determined by VoIP performance testing and monitoring. 6921: 6631: 6417: 6232: 6177: 6172: 5985: 5950: 5401: 5396: 5391: 5204: 3665: 2250: 2040: 1887: 1860: 1846: 1745: 1675: 1667: 1310: 1155:

Telephones for traditional residential analog service are usually connected directly to telephone company

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A VoIP phone is necessary to connect to a VoIP service provider. This can be implemented in several ways:

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The steps and principles involved in originating VoIP telephone calls are similar to traditional digital

6533: 6337: 6302: 6222: 6202: 6124: 6012: 5933: 5461: 4600: 3701: 2959:

Prabhakar, G.; Rastogi, R.; Thotton, M (2005). "OSS Architecture & Requirements for VoIP Networks".

1765: 1686: 1224: 903: 744: 721: 589: 3104: 855:

defines 8 different classes of service (including one dedicated to voice) for traffic on layer-2 wired

103:. They transport media streams using special media delivery protocols that encode audio and video with 5333: 5103: 4902: 4793: 1480:

lifted the ban on VoIPs, in an attempt to reduce operational costs and spur digital entrepreneurship.

783:

DSL modems typically provide Ethernet connections to local equipment, but inside they may actually be

612:

For on-premises systems, local endpoints within the same location typically connect directly over the

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Inter-Network Operations Center Dial-by-ASN (INOC-DBA), a Resource for the Network Operator Community

4979: 3057: 2494:

Montazerolghaem, Ahmadreza; Moghaddam, Mohammad Hossein Yaghmaee; Leon-Garcia, Alberto (March 2018).

2438: 2210: 2072: 1935: 1757: 1489: 1212: 846: 748: 233: 4193:"UAE loosens some VoIP restrictions as residents in lockdown call for end to WhatsApp and Skype ban" 1540:

Internet telephony is permitted to the ISP with restrictions. The following services are permitted:

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International Telecommunication Union, Standardization Sector (ITU-T), Study Group 15 (1993-1996),

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the location is automatically determined from its databases and displayed on the operator console.

1018:

in analog circuitry and an acoustic path from the receive to transmit signal at the receiving end.

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medium to large enterprises, while another is targeting the small-to-medium business (SMB) market.

179: 147: 37: 3662:

Conference Record of the Thirty-Eighth Asilomar Conference on Signals, Systems and Computers, 2004

1048:

because of LCR options, VoIP needs to provide a certain level of reliability when handling calls.

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even for maximum-sized packets. An alternative to preemption on slower links, such as dialup and

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Beyond VoIP Protocols: Understanding Voice Technology and Networking Techniques for IP Telephony

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for quality-of-service mechanisms that help VoIP applications work well even in the presence of

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The technical details of many VoIP protocols create challenges in routing VoIP traffic through

6724: 6646: 6560: 6543: 6506: 6392: 6352: 6182: 6151: 6017: 5911: 5810: 5649: 5509: 5489: 5484: 5386: 5251: 5139: 5082: 4983: 4717: 4528: 4494: 4432: 3775:"NSA Releases Guidance on Securing Unified Communications and Voice and Video over IP Systems" 3683: 3322: 3316: 3185: 2976: 2690: 2650: 2525: 1831: 1729: 1603: 1505: 1409: 1295: 1286:

Secure voice over secure IP may be implemented by encrypting the media with protocols such as

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An end-user is allowed to make PC–to-Phone Internet Telephony calls only on PSTN/PLMN abroad.

3227: 2392: 1095:

Such emergency services are provided by VoIP vendors in the United States by a system called

292:– Transferring the actual media in the call, such as audio, video, text messages, files, etc. 6729: 6689: 6669: 6636: 6565: 6523: 6437: 6292: 6277: 6252: 6227: 6187: 6037: 5896: 5891: 5881: 5531: 5262: 4615: 4484: 3675: 3047: 2968: 2517: 2320: 1973:

1993 Release of VocalChat, a commercial packet network PC voice communication software from

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At the VoIP level, a phone or gateway may identify itself by its account credentials with a

763: 637: 5184: 5003:

Lutzky, Manfred; Schuller, Gerald; Gayer, Marc; Krämer, Ulrich; Wabnik, Stefan (May 2004).

3497: 2731: 374:(SDP), a syntax for session initiation and announcement for multi-media communications and 6357: 6212: 5980: 5943: 5628: 5618: 5269: 5258: 5231: 5191: 4833: 4822: 4404: 4321: 4011: 2887: 1623: 1400:

by the dominant operator, restrictions on the use of VoIP are often imposed, including in

823: 642: 443:

Dedicated VoIP phones connect directly to the IP network using technologies such as wired

72: 5955: 3826: 2028:

US telecommunication companies petition the US Congress to ban Internet phone technology.

1235:

are often employed to enable VoIP calls to and from protected networks. Other methods to

712:

to play it. The added delay is thus a compromise between excessive latency and excessive

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Booth, C (2010). "Chapter 2: IP Phones, Software VoIP, and Integrated and Mobile VoIP".

2120:

network is deployed; this is also the first voice network to reach all seven continents.

1793:

and her team filed many patents related to the technology. By the late 1990s, the first

1376:

Please help update this article to reflect recent events or newly available information.

505:(PBX) lines installed internationally were VoIP. For example, in the United States, the 6555: 6427: 6402: 6362: 6332: 6207: 6042: 5928: 5782: 5767: 5736: 5444: 5051: 5014: 4521:

International Journal of Advanced Research in Computer Science and Software Engineering

2290: 2275: 2097: 2068: 1939: 1761: 1685:

On the early ARPANET, real-time voice communication was not possible with uncompressed

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Throughout the developing world, particularly in countries where regulation is weak or

1164: 1144: 827: 705: 665: 593: 451:. These are typically designed in the style of traditional digital business telephones. 403: 324: 241: 202: 5315: 5282:

Valin, Jean-Marc; Maxwell, Gregory; Terriberry, Timothy B.; Vos, Koen (October 2013).

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may have SIP clients built into the firmware or available as an application download.

6915: 6704: 6477: 6467: 6382: 6272: 6267: 6257: 6242: 6064: 5923: 5741: 5552: 5499: 4540: 3552: 3350: 2205: 2090: 1810: 1782: 1718: 1690: 1236: 1004: 701: 237: 127: 120: 116: 99:, the digital information is packetized and transmission occurs as IP packets over a 2988: 1501:

garnered over 5000 signatures, in response to which the website was blocked in UAE.

6582: 6422: 6367: 6297: 6262: 6197: 6096: 6086: 5938: 5623: 3970: 3416: 3372: 2909: 2537: 2265: 2240: 1955:

1991: Speak Freely, a voice-over-IP application, was released to the public domain.

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standard, which provides a way to create a high-speed (up to 1 gigabit per second)

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to reduce its transmission rate to alleviate the congestion. But VoIP usually uses

385: 63:

specifically refer to the provisioning of voice and other communications services (

5339: 3697: 3271: 1856:(IEEE) publishes a paper entitled "A Protocol for Packet Network Interconnection". 806:, carry Ethernet without intermediate ATM/AAL5 layers, and they generally support 406:, proprietary Internet telephony protocol suite based on peer-to-peer architecture 362:(RTCP), sister protocol for RTP providing stream statistics and status information 4845: 4334: 4258:

Technical Note on Illegal International Long Distance telephone Exchange in India

2757: 1878:

1974: The first successful real-time conversation over ARPANET achieved using 2.4

810:

priority tagging so that VoIP can be queued ahead of less time-critical traffic.

6782: 6432: 6342: 6327: 6287: 6247: 6106: 5731: 5381: 4826: 4690: 3060: 3041: 2355: 2255: 1966: 1959: 1638: 1578: 1334: 1168: 919: 895: 852: 842: 807: 767: 669: 574: 489: 459: 320: 217: 198: 108: 104: 3679: 2495: 6787: 6494: 6192: 6101: 6057: 6027: 6005: 5995: 5970: 5633: 5454: 4619: 4587: 2521: 2162: 2134: 2044: 1898: 1794: 1786: 1658: 1156: 1066: 1014:

Echo can also be an issue for PSTN integration. Common causes of echo include

209: 112: 33: 5043:

MPEG-4 Enhanced Low Delay AAC - A New Standard for High Quality Communication

4721: 4532: 4498: 3570:"Secure Voice over IP (SVoIP) vs. Voice over Secure IP (VoSIP) Installations" 2980: 2529: 1958:

1992: The Frame Relay Forum conducts development of standards for voice over

394:(XMPP), instant messaging, presence information, and contact list maintenance 6772: 6237: 6052: 5746: 5654: 5599: 5466: 5449: 2007: 2003: 1950: 1906: 1602:; make service accessible to people with disabilities; pay regulatory fees, 1322: 1313:– and explaining security risks and mitigation techniques for each of them. 1279: 1263: 1104: 1057: 465: 375: 92: 4290: 1204:, may eliminate the need for personnel to greet and switch incoming calls. 5320: 4469: 3206:"RFC 3824– Using E.164 numbers with the Session Initiation Protocol (SIP)" 420: 16:

Methods of delivering voice communications and multimedia over IP networks

6767: 6757: 6674: 6499: 6322: 5613: 5526: 3800:"Deploying Secure Unified Communications/Voice and Video over IP Systems" 3249: 3205: 2285: 2280: 2166: 2113: 1989: 1974: 1949:, in addition to commercial packet voice products from companies such as 1778: 1773: 1694: 1517: 1509: 1405: 856: 658: 444: 299: 163: 151: 143: 45: 4867: 3139:"Performance and Stress Testing of SIP Servers, Clients and IP Networks" 751:(RTCP) extended reports, SIP RTCP summary reports, H.460.9 Annex B (for 6762: 6747: 5434: 4489: 3172:. ixc.ua. May 20, 2011. Archived from the original on November 11, 2012 2972: 2677:. Total Telecom Online. Archived from the original on February 17, 2006 2368: 2270: 2141: 2094: 1970:

provide the basis for the Real Time Streaming Protocol (RTSP) standard.

1864: 1679: 1299: 1193: 944: in this section. Unsourced material may be challenged and removed. 4924: 1130:

A standards-based solution for reliably delivering fax-over-IP is the

544:

PBX deployment model for connecting an office to local PSTN networks.

6792: 6752: 6074: 5866: 5819: 5504: 5439: 4168:"Etisalat launches new calling app plan days after Skype disruptions" 3343:"Keeping your telephone number when you change your service provider" 3294:"Application-level Network Interoperability and the Evolution of IMS" 3052: 2176: 2154:

codec introduced, using LPC algorithm, and used for voice calling in

2104: 2064: 1924: 1710: 1421: 1401: 1208: 899: 646: 139: 4575:

International Conference on Acoustics, Speech, and Signal Processing

4221:

Mahanagar Doorsanchar Bhawan and Jawahar Lal Nehru Marg (May 2008).

3027:"Optical Packet Buffers for Backbone Internet Routers | Request PDF" 2573: 2010:

initiated standardization activities for VoIP communications system.

1231:, used to interconnect to transit networks or the Internet. Private 739:

A number of protocols have been defined to support the reporting of

298:– Providing out-of-band content or feedback about the media such as 5296: 3475: 2806: 2512: 6777: 6714: 6022: 5424: 3122:"Voice over IP (VoIP) Performance Evaluation on VMware vSphere® 5" 2155: 2124: 2031: 2022: 2018: 1999: 1981: 1946: 1798: 1529: 1513: 1493: 1429: 1267: 1124: 988: 980: 863: 803: 756: 752: 689:(DSL), is to reduce the maximum transmission time by reducing the 588: 532: 518: 448: 419: 347: 335: 213: 194: 187: 175: 171: 167: 159: 138:(MDCT) compression methods. Popular codecs include the MDCT-based 4710:"Network World - Startup targets desktop Videoconferencing arena" 6719: 5557: 5547: 4950: 4428:

Advanced Content Delivery, Streaming, and Cloud Services (Pg 34)

3840:"Hearing Aid Compatibility for Wireline and Wireless Telephones" 2182: 2151: 2144:

wideband codec introduced, using MDCT and CELP (LPC) algorithms.

1913: 1872: 1752:. LPC has since been the most widely used speech coding method. 1736:(NTT) in 1966. LPC was capable of speech compression down to 2.4 1465: 1291: 1255: 1240: 1131: 866: 799: 183: 155: 5823: 5572: 5343: 3901: 3655:"Packet loss concealment in a secure voice over IP environment" 3653:

White, C.M.; Teague, K.A.; Daniel, E.J. (November 7–10, 2004).

3443:"Keep your VoIP E911 service in compliance with this checklist" 1184:

Secure calls are possible using standardized protocols such as

977:

are specially designed to link calls that are passed via VoIP.

5965: 5762: 3757:"Secure VOIP calling, free software, and the right to privacy" 3606:

International Journal of Computer Science and Network Security

2732:"Learn to Make Free or Inexpensive Calls Using SIP on Android" 2326: 1356: 1120: 913: 620: 613: 240:

in applications such as VoIP phones, mobile applications, and

68: 64: 4708:

IDG Network World Inc; Eckerson, Wayne (September 21, 1992).

4514:"Application of MFCC in Text Independent Speaker Recognition" 4116:"Etisalat launches new unlimited calling plan with VoIP apps" 2137:

VoIP service is launched by TelEvolution, Inc. of California.

5568: 3829:, Blog: "Hello Mom, I'm a Fake!" (Telespoof and Fakecaller). 3490:"4.4 VOIP – Regulatory Issues – Universal Service" 2103:

The MDCT is adapted into the LD-MDCT algorithm, used in the

1040:

A voice call originating in the VoIP environment also faces

356:(RTP), transport protocol for real-time audio and video data 4972:

Hersent, Olivier; Petit, Jean-Pierre; Gurle, David (2005).

4691:"The History of VoIP Over the Last 55 Years (1966 to 2021)" 4356: 3975:

Canadian Radio-television and Telecommunications Commission

3864: 1617:

VoIP (fully connected to the PSTN) are mandated to provide

1426:

Canadian Radio-television and Telecommunications Commission

332:(SIP), connection management protocol developed by the IETF 4271:

Stars and Stripes: USFK deal keeps VoIP access for troops

1945:

1986: Proposals from various standards organizations for

1404:

where VoIP is taxed, Guyana where VoIP is prohibited. In

762:

The RTCP extended report VoIP metrics block specified by

5261:

by Timothy B. Terriberry (65 minutes of video, see also

3105:"Methodology for SIP Infrastructure Performance Testing" 3075:

PacketCable Residential SIP Telephony Feature Definition

2637:. EE Times. Archived from the original on August 9, 2011 1200:

the existing data stream. Automated software, such as a

4380:"The State Of Cybersecurity Wiretapping's Fuzzy Future" 1508:. However, popular instant messaging applications like 186:, a codec that uses only 8 kbit/s each way called 5284:

High-Quality, Low-Delay Music Coding in the Opus Codec

5104:"State of the Art: Get Your Free Net Phone Calls Here" 2339: 1532:, it is legal to use VoIP, but it is illegal to have 983:

is a global numbering standard for both the PSTN and

524:

VoIP solutions aimed at businesses have evolved into

4216: 4214: 2329: 2323: 2179:

technology which supports VoIP directly in browsers.

2130:

2004: Commercial VoIP service providers proliferate.

2034:

speech codec introduced, using CELP (LPC) algorithm.

1585:

providing personal Internet services by contract to

6801: 6738: 6660: 6624: 6581: 6522: 6456: 6165: 5857: 5755: 5724: 5663: 5642: 5606: 5540: 5475: 5415: 3878:"network infrastructure: getting started with VoIP" 3088:"VoIP performance measurement using QoS parameters" 2500:

IEEE Transactions on Network and Service Management

2371:

can be used for DSL connectivity without using ATM.

1557:, no other form of Internet Telephony is permitted. 1163:VoIP phones and VoIP telephone adapters connect to 4601:"A Protocol for Packet Network Intercommunication" 1882:kpbs LPC, between Culler-Harrison Incorporated in 1756:(CELP), a type of LPC algorithm, was developed by 4794:"The 10 that Established VOIP (Part 1: VocalTec)" 4636:. The National Science Foundation. Archived from 3779:National Security Agency/Central Security Service 2807:"Social Security to Build "World's Largest VOIP"" 2496:"OpenSIP: Toward Software-Defined SIP Networking" 1980:1994: MTALK, a freeware LAN VoIP application for 1854:Institute of Electrical and Electronics Engineers 1608:Communications Assistance for Law Enforcement Act 1250:Standards for securing VoIP are available in the 5161:"Prospects bright for voice calls over internet" 4903:"The 10 that Established VOIP (Part 2: Level 3)" 4664:"VoIP Basics: Everything Beginners Should Know!" 3190:: CS1 maint: bot: original URL status unknown ( 3077:, Technical Report, PKT-TR-RST-V03-071106 (2007) 2194:codec introduced, using MDCT and LPC algorithms. 999:(usernames) whereas SIP implementations can use 344:(MGCP), connection management for media gateways 3110:. Miroslav Voznak, Jan Rozhon. August 14, 2016. 3043:RTP Control Protocol Extended Reports (RTCP XR) 2830: 2828: 1867:in August 1974, carrying barely intelligible 16 3597:Dunte, Markus; Ruland, Christoph (June 2007). 3000: 2998: 2910:"VoIP - Vulnerability over Internet Protocol?" 2412:"Voice Over IP : Protocols and Standards" 1934:(CELP), a type of LPC algorithm, developed by 1321:Voice over IP protocols and equipment provide 1171:which typically depend on the availability of 5835: 5584: 5355: 5081:. Los Alamitos: IEEE Computer Society Press. 3727:"Cellcrypt secure VOIP heading to BlackBerry" 1797:became available, and new protocols, such as 1101:Wireless Communications and Public Safety Act 424:Example of residential network including VoIP 8: 4925:"RFC 2543, SIP: Session Initiation Protocol" 4567: 4565: 4142:"No Skype? Pay Dh50 monthly for video calls" 4063:"Saudi Arabia to lift ban on internet calls" 4037:"Saudi Arabia to lift ban on internet calls" 3406:"FCC Consumer Advisory VoIP and 911 Service" 2631:"WIRELESS: Carriers look to IP for backhaul" 2437:and the common encryption mechanism used is 2310:Variously pronounced as individual letters, 2169:, which uses the LD-MDCT-based AAC-LD codec. 1337:compatibility requirements set forth by the 1239:devices involve assistive protocols such as 32:, is a method and group of technologies for 6850:Global telecommunications regulation bodies 4927:. Handley, Schulzrinne, Schooler, Rosenberg 1282:, facilitate capturing VoIP conversations. 6886: 5842: 5828: 5820: 5591: 5577: 5569: 5362: 5348: 5340: 4578:(ICASSP), vol. 10, pp. 937–940, 1985. 3521:"Examining Two Well-Known Attacks on VoIP" 3170:"Importance of Softswitch VoIP Technology" 2783:. Government Computer News. Archived from 987:(PLMN). Most VoIP implementations support 400:, for peer-to-peer session control in XMPP 392:Extensible Messaging and Presence Protocol 5295: 5228:"Inside iPhone 4: FaceTime video calling" 4774:. Computer Telephony Interaction Magazine 4488: 3669: 3373:"TelePassport takes the sting out of MNP" 3051: 2511: 2057:(SIP) specification RFC 2543 is released. 960:Learn how and when to remove this message 672:. This signals a transport protocol like 75:) over the Internet, rather than via the 4114:Debusmann, Bernd Jr. (January 9, 2018). 3252:. The Internet Society. December 1, 2004 2933: 2931: 2929: 2927: 2925: 2923: 232:Voice over IP has been implemented with 4463: 4461: 4459: 4457: 4455: 4291:"Cybertelecom :: VoIP :: FCC" 4012:"Oman cuffs 212 for selling VoIP calls" 3630:Stringfellow, Brian (August 15, 2001). 3441:Noworatzky, Daniel (February 6, 2019). 3153:"Testing Voice over IP (VolP) Networks" 2835:Korzeniowski, Peter (January 8, 2009). 2384: 2303: 2185:codec introduced, using MDCT algorithm. 1188:. Most of the facilities of creating a 602: 428:Mass-market VoIP services use existing 4657: 4655: 4089:"Don't worry, Skype is working in UAE" 3551:. DISA. April 21, 2006. Archived from 3400: 3398: 3183: 3006:"Quality of Service for Voice over IP" 2939:"Quality of Service for Voice over IP" 2688: 2648: 2354:IP networks may also be more prone to 1245:Interactive Connectivity Establishment 1081:roaming via another cellular company. 716:, i.e. momentary audio interruptions. 5159:Remo, Michelle V. (August 27, 2007). 4357:"Voice Over Internet Protocol (VoIP)" 4166:Zacharias, Anna \ (January 8, 2018). 3977:. Government of Canada. April 4, 2005 2837:"Three Technologies You Need In 2009" 2588:"Voice Over Internet Protocol (VoIP)" 2216:Comparison of audio network protocols 1724:algorithm that was first proposed by 1643:Foreign Intelligence Surveillance Act 1630:via wholesale carriers. Providers of 1274:VoIP at the transport level by using 972:A VoIP media gateway controller (aka 7: 6896: 5207:. Wirevolution.com. January 13, 2009 5131:VoIP Voice and Fax Signal Processing 3619:from the original on April 19, 2023. 3208:. The Internet Society. June 1, 2004 3093:. A.H.Muhamad Amin. August 14, 2016. 2861:Callahan, Renee (December 9, 2008). 1641:is debating concerns changes to the 1088:(SIP) registrar. In such cases, the 942:adding citations to reliable sources 747:(QoE) for VoIP calls. These include 360:Real-time Transport Control Protocol 5226:Daniel Eran Dilger (June 8, 2010). 4608:IEEE Transactions on Communications 3867:, What are some advantages of VoIP? 2410:Arora, Rakesh (November 23, 1999). 1996:commercial Internet phone software. 1713:. The solution to this problem was 1563:Internet Assigned Numbers Authority 1252:Secure Real-time Transport Protocol 1186:Secure Real-time Transport Protocol 1090:Internet telephony service provider 573:Typically this will be one or more 366:Secure Real-time Transport Protocol 130:standards in VoIP are based on the 5205:"Skype's new super wideband codec" 4689:McCraw, Corey (October 12, 2022). 4140:Maceda, Cleofe (January 8, 2018). 3902:"Global VOIP Policy Status Matrix" 3642:from the original on June 1, 2023. 3383:from the original on July 19, 2022 2863:"Businesses Move To Voice-Over-IP" 2087:modified discrete cosine transform 1764:in 1985. LPC algorithms remain an 873:(LAN) using existing home wiring ( 822:Several protocols are used in the 136:modified discrete cosine transform 14: 5128:Nagireddi, Sivannarayana (2008). 3844:Federal Communications Commission 3664:. Vol. 1. pp. 415–419. 2813:from the original on June 2, 2009 2779:Jackson, William (May 27, 2009). 2592:Federal Communications Commission 1674:in 1973 which was developed into 1628:incumbent local exchange carriers 1544:PC to PC; within or outside India 1339:Federal Communications Commission 1298:on a classified network, such as 1035:Federal Communications Commission 474:PSTN and mobile network providers 77:public switched telephone network 6895: 6885: 6876: 6875: 6864: 6485:Free-space optical communication 5804: 5794: 5328: 5314: 5006:A guideline to audio codec delay 4378:Greenberg, Andy (May 15, 2008). 3519:Thermos, Peter (April 5, 2006). 2752:Michael Dosch and Steve Church. 2319: 1678:which operated across the early 1553:Except whatever is described in 1361: 918: 841:is an approved amendment to the 368:(SRTP), encrypted version of RTP 5371:Computer-mediated communication 5102:Pogue, David (August 2, 2007). 4599:Cerf, V.; Kahn, R. (May 1974). 3971:"Telecom Decision CRTC 2005-21" 3141:. StarTrinity. August 13, 2016. 2043:began development of its first 1701:kbps, much greater than the 2.4 1011:(ENUM) service in IMS and SIP. 929:needs additional citations for 5252:Presentation of the CELT codec 4949:. Asterisk.org. Archived from 4716:. IDG Network World Inc: 39–. 4431:. Willey. September 19, 2014. 3957:"VOICE OVER INTERNET PROTOCOL" 2754:"VoIP in the Broadcast Studio" 1932:Code-excited linear prediction 1903:Information Sciences Institute 1836:Nippon Telegraph and Telephone 1754:Code-excited linear prediction 1734:Nippon Telegraph and Telephone 1666:of the mid-twentieth century. 507:Social Security Administration 342:Media Gateway Control Protocol 1: 5319:The dictionary definition of 5077:Stapleton-Gray, Ross (2009). 3272:"Your personal online number" 2397:Cambridge Dictionaries Online 2231:High Bit Rate Media Transport 2047:, a term they coined in 1998. 1670:first demonstrated a form of 1637:Another legal issue that the 1626:and exchange of traffic with 995:allows subscribers to choose 885:with the network controllers. 724:, jitter can be modeled as a 596:-based PBX for small business 384:(IAX), protocol used between 6871:Telecommunication portal 6652:Telecommunications equipment 5801:Telecommunication portal 5407:Virtual learning environment 5336:travel guide from Wikivoyage 4477:Found. Trends Signal Process 3321:. Cisco Press. p. 557. 2756:. Axia Audio. Archived from 1923:commissions the creation of 1294:. Secure voice over IP uses 462:have this function built in. 372:Session Description Protocol 354:Real-time Transport Protocol 22:Voice over Internet Protocol 6388:Alexander Stepanovich Popov 5520:Voice chat in online gaming 4662:Dua, Amit (July 29, 2021). 3577:General Dynamics C4 Systems 2961:Bell Labs Technical Journal 2552:"H.323 and SIP Integration" 2221:Comparison of VoIP software 2116:, the first inter-provider 2055:Session Initiation Protocol 1921:National Science Foundation 1803:Session Initiation Protocol 1768:in modern VoIP technology. 1353:Regulatory and legal issues 1229:network address translators 1086:Session Initiation Protocol 1056:A telephone connected to a 1009:E.164 number to URI mapping 1001:Uniform Resource Identifier 330:Session Initiation Protocol 81:plain old telephone service 44:(IP) networks, such as the 6958: 6092:Telecommunications history 5190:February 10, 2013, at the 4769:"Internet Phone Release 4" 4512:Gupta, Shipra (May 2016). 3904:. Global IP Alliance. 2005 3680:10.1109/ACSSC.2004.1399165 3318:Packetcable Implementation 3296:. TMCnet.com. May 24, 2006 3127:. VMware. August 14, 2016. 2477:Library Technology Reports 2435:Layer 2 Tunneling Protocol 2089:(MDCT) is adopted for the 1653:The early developments of 1587:United States Forces Korea 1583:Internet service providers 1233:session border controllers 985:public land mobile network 796:virtual circuit identifier 785:Asynchronous Transfer Mode 264:– Creating and managing a 6859: 6700:Public Switched Telephone 6512:telecommunication circuit 6473:Fiber-optic communication 6218:Francis Blake (telephone) 6013:Optical telecommunication 5791: 5676:Communications satellites 5417:Asynchronous conferencing 5377: 5288:Audio Engineering Society 5165:Philippine Daily Inquirer 5057:Audio Engineering Society 5020:Audio Engineering Society 4821:October 30, 2013, at the 4620:10.1109/TCOM.1974.1092259 3468:"Faxing over IP networks" 2914:www.continuitycentral.com 2809:. Government Technology. 2695:: CS1 maint: unfit URL ( 2655:: CS1 maint: unfit URL ( 2522:10.1109/TNSM.2017.2741258 2085:(DCT) variant called the 2083:discrete cosine transform 1370:This section needs to be 1329:Hearing aid compatibility 1260:analog telephony adapters 1031:mobile number portability 834:. Some examples include: 759:.30 and MGCP extensions. 691:maximum transmission unit 430:broadband Internet access 201:, adopted the concept of 6611:Orbital angular-momentum 6048:Satellite communications 5887:Communications satellite 5477:Synchronous conferencing 5286:. 135th AES Convention. 5268:August 10, 2011, at the 5049:. 125th AES Convention. 5012:. 116th AES Convention. 4827:VoiP Developer Solutions 4573:Proceedings of the IEEE 4468:Gray, Robert M. (2010). 4324:, 47 C.F.R. pt. 9 (2007) 3158:. IXIA. August 14, 2016. 2456:. Google Talkabout. 2006 1916:is described in RFC 791. 1892:Lexington, Massachusetts 1824:Linear predictive coding 1750:Lexington, Massachusetts 1715:linear predictive coding 1600:local number portability 1307:National Security Agency 1276:opportunistic encryption 1137:analog telephone adapter 1027:Local number portability 726:Gaussian random variable 700:results from changes in 456:analog telephone adapter 312:VoIP protocols include: 242:web-based communications 132:linear predictive coding 97:circuit-switched network 6937:Audio network protocols 6490:Molecular communication 6313:Gardiner Greene Hubbard 6142:Undersea telegraph line 5877:Cable protection system 5671:Cable protection system 5430:Electronic mailing list 5257:August 7, 2011, at the 4905:. iLocus. July 13, 2007 4407:. INTERNET HALL of FAME 3494:ICT Regulation Tool Kit 2671:"Mobile's IP challenge" 2246:IP Multimedia Subsystem 2226:Differentiated services 2076:private branch exchange 1781:, based on a patent by 1270:is available to secure 1078:off-premises extensions 1074:virtual private network 787:(ATM) modems. They use 687:digital subscriber line 655:geostationary satellite 503:Private branch exchange 382:Inter-Asterisk eXchange 236:and protocols based on 119:, while others support 101:packet-switched network 61:broadband phone service 6632:Communication protocol 6418:Charles Sumner Tainter 6233:Walter Houser Brattain 6178:Edwin Howard Armstrong 5986:Information revolution 5402:Social network service 5397:Collaborative software 5392:Communication software 4832:June 16, 2011, at the 4697:. Fits Small Business. 4670:. Business 2 Community 4668:business2community.com 4634:"The Launch of NSFNET" 4335:"VoIP and 911 Service" 3923:Proenza, Francisco J. 3890:on September 17, 2011. 3761:Free Software Magazine 3632:"Secure Voice Over IP" 3599:"Secure Voice-over-IP" 3586:on September 24, 2015. 2781:"SSA goes big on VOIP" 2574:"Voice OVER IP (VOIP)" 2358:that cause congestion. 2251:List of VoIP companies 1897:1977: Danny Cohen and 1888:MIT Lincoln Laboratory 1861:Network Voice Protocol 1746:MIT Lincoln Laboratory 1676:Network Voice Protocol 1262:, as well as for some 789:ATM Adaptation Layer 5 698:Packet delay variation 597: 526:unified communications 434:direct inbound dialing 425: 222:unified communications 146:), the LPC/MDCT-based 79:(PSTN), also known as 6606:Polarization-division 6338:Narinder Singh Kapany 6303:Erna Schneider Hoover 6223:Jagadish Chandra Bose 6203:Alexander Graham Bell 5934:online video platform 5811:Telephones portal 5462:Bulletin board system 5136:John Wiley & Sons 4980:John Wiley & Sons 4320:June 8, 2010, at the 4256:Harish Kumar Gangwar 3478:on December 18, 2023. 3379:. November 13, 2006. 3228:"Create a Skype Name" 2367:Technologies such as 1766:audio coding standard 1693:packets, which had a 1687:pulse-code modulation 1099:(E911), based on the 745:quality of experience 722:central limit theorem 592: 423: 323:, voice over IP, and 234:proprietary protocols 182:voice codec known as 126:The most widely used 6448:Vladimir K. Zworykin 6408:Almon Brown Strowger 6378:Charles Grafton Page 6033:Prepaid mobile phone 5961:Electrical telegraph 5773:Telephone newspapers 4890:Recommendation G.729 4695:fitsmallbusiness.com 4527:(5): 805–810 (806). 4295:www.cybertelecom.org 4069:. September 20, 2017 4043:. September 20, 2017 3353:on December 12, 2009 3315:Jeff Riddel (2007). 2888:"Skype For Business" 2711:"Android SIP Client" 2439:Secure Sockets Layer 2211:Call-through telecom 1936:Manfred R. Schroeder 1758:Manfred R. Schroeder 1555:condition (ii) above 1490:United Arab Emirates 1484:United Arab Emirates 1213:VoIP vulnerabilities 1016:impedance mismatches 938:improve this article 847:media access control 749:RTP Control Protocol 585:Private VoIP systems 319:, open standard for 36:for the delivery of 6398:Johann Philipp Reis 6157:Wireless revolution 6119:The Telephone Cases 5976:Hydraulic telegraph 5696:Mobile phone signal 5495:Internet Relay Chat 5263:presentation slides 4953:on January 23, 2009 4550:on October 18, 2019 4359:. November 18, 2010 4337:. FCC. May 26, 2011 4278:on January 13, 2010 3558:on August 25, 2009. 2594:. November 18, 2010 2422:on January 19, 2024 2261:RTP payload formats 2236:Integrated services 2093:codec, used in the 1834:and Shuzo Saito of 1732:and Shuzo Saito of 1476:In September 2017, 1452:Arab states of the 1432:emergency service. 890:Performance metrics 773:mean opinion scores 645:, packet loss, and 559:Hosted VoIP systems 539:Delivery mechanisms 57:broadband telephony 38:voice communication 6596:Frequency-division 6573:Telephone exchange 6443:Charles Wheatstone 6373:Jun-ichi Nishizawa 6348:Innocenzo Manzetti 6283:Reginald Fessenden 6018:Optical telegraphy 5851:Telecommunications 5686:Free-space optical 5334:Internet telephony 5108:The New York Times 4947:"What is Asterisk" 4490:10.1561/2000000036 4235:on October 6, 2014 3846:. October 30, 2014 3422:on August 10, 2010 2973:10.1002/bltj.20077 2760:on October 7, 2011 1884:Goleta, California 1863:(NVP) tested over 1826:(LPC) proposed by 1742:Goleta, California 1664:telecommunications 1305:In June 2021, the 1211:with knowledge of 1151:Power requirements 1042:least-cost routing 1022:Number portability 1003:(URIs) similar to 877:, phone lines and 871:Local area network 832:network congestion 741:quality of service 634:quality of service 627:Quality of service 598: 515:personal computers 426: 302:, statistics, etc. 296:Quality of service 262:Session management 53:Internet telephony 51:The broader terms 6909: 6908: 6647:Store and forward 6642:Data transmission 6556:Network switching 6507:Transmission line 6353:Guglielmo Marconi 6318:Internet pioneers 6183:Mohamed M. Atalla 6152:Whistled language 5817: 5816: 5650:Answering machine 5566: 5565: 5510:Videoconferencing 5490:Instant messaging 5485:Data conferencing 5387:Online discussion 5088:978-0-7695-3568-5 4814:The free Library 4588:Audio Transceiver 4289:Pershing, Genny. 3807:media.defense.gov 3737:on April 24, 2009 3689:978-0-7803-8622-8 3328:978-1-58705-181-4 2675:www.totaltele.com 2454:"XMPP Federation" 1832:Nagoya University 1730:Nagoya University 1604:universal service 1506:COVID-19 pandemic 1410:telecommunication 1391: 1390: 1296:Type 1 encryption 1217:denial-of-service 1173:mains electricity 970: 969: 962: 794:Using a separate 601:QoS control (see 284:Media description 216:or the carrier's 154:), the LPC-based 117:compressed speech 42:Internet Protocol 6949: 6942:Office equipment 6899: 6898: 6889: 6888: 6879: 6878: 6869: 6868: 6867: 6740:Notable networks 6730:Wireless network 6670:Cellular network 6662:Types of network 6637:Computer network 6524:Network topology 6438:Thomas A. Watson 6293:Oliver Heaviside 6278:Philo Farnsworth 6253:Daniel Davis Jr. 6228:Charles Bourseul 6188:John Logie Baird 5897:Data compression 5892:Computer network 5844: 5837: 5830: 5821: 5809: 5808: 5807: 5799: 5798: 5797: 5763:Fax transmission 5711:Submarine cables 5593: 5586: 5579: 5570: 5532:Web conferencing 5467:Online guestbook 5364: 5357: 5350: 5341: 5332: 5318: 5302: 5301: 5299: 5279: 5273: 5249: 5243: 5242: 5240: 5238: 5223: 5217: 5216: 5214: 5212: 5201: 5195: 5185:Audio-Mitschnitt 5182: 5176: 5175: 5173: 5171: 5156: 5150: 5149: 5125: 5119: 5118: 5116: 5114: 5099: 5093: 5092: 5074: 5068: 5067: 5065: 5063: 5048: 5037: 5031: 5030: 5028: 5026: 5011: 5000: 4994: 4993: 4969: 4963: 4962: 4960: 4958: 4943: 4937: 4936: 4934: 4932: 4921: 4915: 4914: 4912: 4910: 4899: 4893: 4886: 4880: 4879: 4877: 4875: 4864: 4858: 4857: 4855: 4853: 4842: 4836: 4812: 4806: 4805: 4803: 4801: 4790: 4784: 4783: 4781: 4779: 4773: 4764: 4758: 4757: 4755: 4753: 4747: 4739: 4733: 4732: 4730: 4728: 4705: 4699: 4698: 4686: 4680: 4679: 4677: 4675: 4659: 4650: 4649: 4647: 4645: 4630: 4624: 4623: 4605: 4596: 4590: 4585: 4579: 4569: 4560: 4559: 4557: 4555: 4549: 4543:. Archived from 4518: 4509: 4503: 4502: 4492: 4474: 4465: 4450: 4449: 4447: 4445: 4423: 4417: 4416: 4414: 4412: 4401: 4395: 4394: 4392: 4390: 4375: 4369: 4368: 4366: 4364: 4353: 4347: 4346: 4344: 4342: 4331: 4325: 4312: 4306: 4305: 4303: 4301: 4286: 4280: 4279: 4274:, archived from 4266: 4260: 4254: 4248: 4247: 4242: 4240: 4234: 4227: 4218: 4209: 4208: 4206: 4204: 4199:. March 26, 2020 4189: 4183: 4182: 4180: 4178: 4163: 4157: 4156: 4154: 4152: 4137: 4131: 4130: 4128: 4126: 4120:Arabian Business 4111: 4105: 4104: 4102: 4100: 4085: 4079: 4078: 4076: 4074: 4059: 4053: 4052: 4050: 4048: 4033: 4027: 4026: 4024: 4022: 4007: 4001: 4000: 3993: 3987: 3986: 3984: 3982: 3967: 3961: 3960: 3953: 3947: 3946: 3944: 3942: 3936: 3930:. Archived from 3929: 3920: 3914: 3913: 3911: 3909: 3898: 3892: 3891: 3889: 3883:. Archived from 3882: 3874: 3868: 3862: 3856: 3855: 3853: 3851: 3836: 3830: 3824: 3818: 3817: 3815: 3813: 3804: 3796: 3790: 3789: 3787: 3785: 3771: 3765: 3764: 3753: 3747: 3746: 3744: 3742: 3733:. Archived from 3731:Networkworld.com 3723: 3717: 3716: 3714: 3712: 3706: 3700:. Archived from 3673: 3659: 3650: 3644: 3643: 3627: 3621: 3620: 3618: 3603: 3594: 3588: 3587: 3585: 3579:. Archived from 3574: 3566: 3560: 3559: 3557: 3550: 3542: 3536: 3535: 3533: 3531: 3516: 3510: 3509: 3507: 3505: 3496:. Archived from 3486: 3480: 3479: 3474:. Archived from 3464: 3458: 3457: 3455: 3453: 3438: 3432: 3431: 3429: 3427: 3421: 3415:. Archived from 3410: 3402: 3393: 3392: 3390: 3388: 3369: 3363: 3362: 3360: 3358: 3349:. Archived from 3339: 3333: 3332: 3312: 3306: 3305: 3303: 3301: 3290: 3284: 3283: 3281: 3279: 3268: 3262: 3261: 3259: 3257: 3246: 3240: 3239: 3237: 3235: 3224: 3218: 3217: 3215: 3213: 3202: 3196: 3195: 3189: 3181: 3179: 3177: 3166: 3160: 3159: 3157: 3149: 3143: 3142: 3135: 3129: 3128: 3126: 3118: 3112: 3111: 3109: 3101: 3095: 3094: 3092: 3084: 3078: 3071: 3065: 3064: 3055: 3053:10.17487/RFC3611 3040:Caceres, Ramon. 3037: 3031: 3030: 3023: 3017: 3016: 3014: 3012: 3002: 2993: 2992: 2956: 2950: 2949: 2947: 2945: 2935: 2918: 2917: 2906: 2900: 2899: 2897: 2895: 2884: 2878: 2877: 2875: 2873: 2858: 2852: 2851: 2849: 2847: 2832: 2823: 2822: 2820: 2818: 2803: 2797: 2796: 2794: 2792: 2787:on July 28, 2011 2776: 2770: 2769: 2767: 2765: 2749: 2743: 2742: 2740: 2738: 2728: 2722: 2721: 2719: 2717: 2707: 2701: 2700: 2694: 2686: 2684: 2682: 2667: 2661: 2660: 2654: 2646: 2644: 2642: 2627: 2621: 2620: 2618: 2610: 2604: 2603: 2601: 2599: 2584: 2578: 2577: 2569: 2563: 2562: 2560: 2558: 2548: 2542: 2541: 2515: 2491: 2485: 2484: 2472: 2466: 2465: 2463: 2461: 2450: 2444: 2443: 2429: 2427: 2418:. Archived from 2407: 2401: 2400: 2389: 2372: 2365: 2359: 2352: 2346: 2342: 2336: 2335: 2332: 2331: 2328: 2325: 2316: 2308: 2100:coding standard. 1881: 1870: 1828:Fumitada Itakura 1739: 1726:Fumitada Itakura 1722:data compression 1704: 1700: 1556: 1386: 1383: 1377: 1365: 1364: 1357: 1345:Operational cost 1190:secure telephone 965: 958: 954: 951: 945: 922: 914: 910:PSTN integration 730:bottleneck links 638:circuit switched 621:site-to-site VPN 6957: 6956: 6952: 6951: 6950: 6948: 6947: 6946: 6912: 6911: 6910: 6905: 6865: 6863: 6855: 6797: 6734: 6656: 6620: 6577: 6526: 6518: 6459: 6452: 6358:Robert Metcalfe 6213:Tim Berners-Lee 6161: 5981:Information Age 5853: 5848: 5818: 5813: 5805: 5803: 5795: 5793: 5787: 5768:Telephone calls 5751: 5720: 5659: 5638: 5629:Satellite phone 5619:Cable telephony 5602: 5597: 5567: 5562: 5536: 5471: 5411: 5373: 5368: 5311: 5306: 5305: 5281: 5280: 5276: 5270:Wayback Machine 5259:Wayback Machine 5250: 5246: 5236: 5234: 5225: 5224: 5220: 5210: 5208: 5203: 5202: 5198: 5192:Wayback Machine 5183: 5179: 5169: 5167: 5158: 5157: 5153: 5146: 5127: 5126: 5122: 5112: 5110: 5101: 5100: 5096: 5089: 5076: 5075: 5071: 5061: 5059: 5046: 5039: 5038: 5034: 5024: 5022: 5009: 5002: 5001: 4997: 4990: 4971: 4970: 4966: 4956: 4954: 4945: 4944: 4940: 4930: 4928: 4923: 4922: 4918: 4908: 4906: 4901: 4900: 4896: 4887: 4883: 4873: 4871: 4866: 4865: 4861: 4851: 4849: 4844: 4843: 4839: 4834:Wayback Machine 4823:Wayback Machine 4813: 4809: 4799: 4797: 4792: 4791: 4787: 4777: 4775: 4771: 4766: 4765: 4761: 4751: 4749: 4745: 4741: 4740: 4736: 4726: 4724: 4707: 4706: 4702: 4688: 4687: 4683: 4673: 4671: 4661: 4660: 4653: 4643: 4641: 4632: 4631: 4627: 4603: 4598: 4597: 4593: 4586: 4582: 4570: 4563: 4553: 4551: 4547: 4516: 4511: 4510: 4506: 4472: 4467: 4466: 4453: 4443: 4441: 4439: 4425: 4424: 4420: 4410: 4408: 4403: 4402: 4398: 4388: 4386: 4377: 4376: 4372: 4362: 4360: 4355: 4354: 4350: 4340: 4338: 4333: 4332: 4328: 4322:Wayback Machine 4313: 4309: 4299: 4297: 4288: 4287: 4283: 4268: 4267: 4263: 4255: 4251: 4238: 4236: 4232: 4225: 4220: 4219: 4212: 4202: 4200: 4191: 4190: 4186: 4176: 4174: 4165: 4164: 4160: 4150: 4148: 4139: 4138: 4134: 4124: 4122: 4113: 4112: 4108: 4098: 4096: 4095:. June 26, 2017 4087: 4086: 4082: 4072: 4070: 4061: 4060: 4056: 4046: 4044: 4035: 4034: 4030: 4020: 4018: 4009: 4008: 4004: 3997:"Voice over IP" 3995: 3994: 3990: 3980: 3978: 3969: 3968: 3964: 3955: 3954: 3950: 3940: 3938: 3937:on June 2, 2012 3934: 3927: 3922: 3921: 3917: 3907: 3905: 3900: 3899: 3895: 3887: 3880: 3876: 3875: 3871: 3863: 3859: 3849: 3847: 3838: 3837: 3833: 3825: 3821: 3811: 3809: 3802: 3798: 3797: 3793: 3783: 3781: 3773: 3772: 3768: 3755: 3754: 3750: 3740: 3738: 3725: 3724: 3720: 3710: 3708: 3707:on May 17, 2006 3704: 3690: 3657: 3652: 3651: 3647: 3629: 3628: 3624: 3616: 3601: 3596: 3595: 3591: 3583: 3572: 3568: 3567: 3563: 3555: 3548: 3544: 3543: 3539: 3529: 3527: 3518: 3517: 3513: 3503: 3501: 3500:on June 4, 2009 3488: 3487: 3483: 3472:Soft-Switch.org 3466: 3465: 3461: 3451: 3449: 3440: 3439: 3435: 3425: 3423: 3419: 3408: 3404: 3403: 3396: 3386: 3384: 3371: 3370: 3366: 3356: 3354: 3341: 3340: 3336: 3329: 3314: 3313: 3309: 3299: 3297: 3292: 3291: 3287: 3277: 3275: 3270: 3269: 3265: 3255: 3253: 3248: 3247: 3243: 3233: 3231: 3226: 3225: 3221: 3211: 3209: 3204: 3203: 3199: 3182: 3175: 3173: 3168: 3167: 3163: 3155: 3151: 3150: 3146: 3137: 3136: 3132: 3124: 3120: 3119: 3115: 3107: 3103: 3102: 3098: 3090: 3086: 3085: 3081: 3072: 3068: 3039: 3038: 3034: 3025: 3024: 3020: 3010: 3008: 3004: 3003: 2996: 2958: 2957: 2953: 2943: 2941: 2937: 2936: 2921: 2908: 2907: 2903: 2893: 2891: 2886: 2885: 2881: 2871: 2869: 2860: 2859: 2855: 2845: 2843: 2834: 2833: 2826: 2816: 2814: 2805: 2804: 2800: 2790: 2788: 2778: 2777: 2773: 2763: 2761: 2751: 2750: 2746: 2736: 2734: 2730: 2729: 2725: 2715: 2713: 2709: 2708: 2704: 2687: 2680: 2678: 2669: 2668: 2664: 2647: 2640: 2638: 2635:www.eetimes.com 2629: 2628: 2624: 2616: 2612: 2611: 2607: 2597: 2595: 2586: 2585: 2581: 2571: 2570: 2566: 2556: 2554: 2550: 2549: 2545: 2493: 2492: 2488: 2474: 2473: 2469: 2459: 2457: 2452: 2451: 2447: 2425: 2423: 2409: 2408: 2404: 2391: 2390: 2386: 2381: 2376: 2375: 2366: 2362: 2353: 2349: 2340: 2322: 2318: 2311: 2309: 2305: 2300: 2295: 2201: 2078:(PBX) software. 1879: 1868: 1845:application by 1819: 1737: 1702: 1698: 1651: 1624:interconnection 1595: 1575: 1554: 1526: 1486: 1474: 1462: 1457: 1438: 1418: 1387: 1381: 1378: 1375: 1366: 1362: 1355: 1347: 1331: 1319: 1254:(SRTP) and the 1182: 1153: 1117: 1054: 1052:Emergency calls 1024: 1005:email addresses 966: 955: 949: 946: 935: 923: 912: 892: 824:data link layer 820: 781: 666:queueing delays 629: 587: 561: 541: 498: 476: 418: 416:Consumer market 413: 300:synchronization 230: 208:In addition to 123:stereo codecs. 89: 73:voice messaging 28:), also called 17: 12: 11: 5: 6955: 6953: 6945: 6944: 6939: 6934: 6932:Videotelephony 6929: 6924: 6914: 6913: 6907: 6906: 6904: 6903: 6893: 6883: 6873: 6860: 6857: 6856: 6854: 6853: 6846: 6841: 6836: 6831: 6826: 6825: 6824: 6819: 6811: 6805: 6803: 6799: 6798: 6796: 6795: 6790: 6785: 6780: 6775: 6770: 6765: 6760: 6755: 6750: 6744: 6742: 6736: 6735: 6733: 6732: 6727: 6722: 6717: 6712: 6707: 6702: 6697: 6692: 6687: 6682: 6677: 6672: 6666: 6664: 6658: 6657: 6655: 6654: 6649: 6644: 6639: 6634: 6628: 6626: 6622: 6621: 6619: 6618: 6613: 6608: 6603: 6598: 6593: 6591:Space-division 6587: 6585: 6579: 6578: 6576: 6575: 6570: 6569: 6568: 6563: 6553: 6552: 6551: 6541: 6536: 6530: 6528: 6520: 6519: 6517: 6516: 6515: 6514: 6504: 6503: 6502: 6492: 6487: 6482: 6481: 6480: 6470: 6464: 6462: 6454: 6453: 6451: 6450: 6445: 6440: 6435: 6430: 6428:Camille Tissot 6425: 6420: 6415: 6410: 6405: 6403:Claude Shannon 6400: 6395: 6393:Tivadar Puskás 6390: 6385: 6380: 6375: 6370: 6365: 6363:Antonio Meucci 6360: 6355: 6350: 6345: 6340: 6335: 6333:Charles K. Kao 6330: 6325: 6320: 6315: 6310: 6308:Harold Hopkins 6305: 6300: 6295: 6290: 6285: 6280: 6275: 6270: 6265: 6260: 6255: 6250: 6245: 6240: 6235: 6230: 6225: 6220: 6215: 6210: 6208:Emile Berliner 6205: 6200: 6195: 6190: 6185: 6180: 6175: 6169: 6167: 6163: 6162: 6160: 6159: 6154: 6149: 6147:Videotelephony 6144: 6139: 6138: 6137: 6132: 6122: 6115: 6110: 6104: 6099: 6094: 6089: 6084: 6083: 6082: 6077: 6072: 6062: 6061: 6060: 6050: 6045: 6043:Radiotelephone 6040: 6035: 6030: 6025: 6020: 6015: 6010: 6009: 6008: 5998: 5993: 5988: 5983: 5978: 5973: 5968: 5963: 5958: 5953: 5948: 5947: 5946: 5941: 5936: 5931: 5929:Internet video 5921: 5920: 5919: 5914: 5909: 5904: 5894: 5889: 5884: 5879: 5874: 5869: 5863: 5861: 5855: 5854: 5849: 5847: 5846: 5839: 5832: 5824: 5815: 5814: 5792: 5789: 5788: 5786: 5785: 5780: 5775: 5770: 5765: 5759: 5757: 5753: 5752: 5750: 5749: 5744: 5739: 5737:Misdialed call 5734: 5728: 5726: 5722: 5721: 5719: 5718: 5713: 5708: 5703: 5698: 5693: 5688: 5683: 5678: 5673: 5667: 5665: 5661: 5660: 5658: 5657: 5652: 5646: 5644: 5640: 5639: 5637: 5636: 5631: 5626: 5621: 5616: 5610: 5608: 5604: 5603: 5598: 5596: 5595: 5588: 5581: 5573: 5564: 5563: 5561: 5560: 5555: 5550: 5544: 5542: 5538: 5537: 5535: 5534: 5529: 5524: 5523: 5522: 5512: 5507: 5502: 5497: 5492: 5487: 5481: 5479: 5473: 5472: 5470: 5469: 5464: 5459: 5458: 5457: 5452: 5445:Internet forum 5442: 5437: 5432: 5427: 5421: 5419: 5413: 5412: 5410: 5409: 5404: 5399: 5394: 5389: 5384: 5378: 5375: 5374: 5369: 5367: 5366: 5359: 5352: 5344: 5338: 5337: 5326: 5310: 5309:External links 5307: 5304: 5303: 5274: 5244: 5218: 5196: 5177: 5151: 5144: 5138:. p. 69. 5120: 5094: 5087: 5069: 5052:Fraunhofer IIS 5032: 5015:Fraunhofer IIS 4995: 4988: 4982:. p. 55. 4964: 4938: 4916: 4894: 4881: 4859: 4837: 4807: 4785: 4767:Keating, Tom. 4759: 4743:"MTALK-Readme" 4734: 4700: 4681: 4651: 4640:on May 7, 2006 4625: 4614:(5): 637–648. 4591: 4580: 4561: 4504: 4483:(4): 203–303. 4451: 4437: 4418: 4396: 4370: 4348: 4326: 4307: 4281: 4261: 4249: 4210: 4184: 4158: 4132: 4106: 4080: 4054: 4028: 4002: 3988: 3962: 3948: 3915: 3893: 3869: 3857: 3831: 3819: 3791: 3766: 3748: 3718: 3688: 3671:10.1.1.219.633 3645: 3636:SANS Institute 3622: 3589: 3561: 3537: 3511: 3481: 3459: 3433: 3394: 3364: 3334: 3327: 3307: 3285: 3263: 3241: 3219: 3197: 3161: 3144: 3130: 3113: 3096: 3079: 3066: 3032: 3018: 2994: 2951: 2919: 2901: 2879: 2853: 2824: 2798: 2771: 2744: 2723: 2702: 2662: 2622: 2605: 2579: 2564: 2543: 2506:(1): 184–199. 2486: 2467: 2445: 2402: 2383: 2382: 2380: 2377: 2374: 2373: 2360: 2347: 2317:or as a word, 2302: 2301: 2299: 2296: 2294: 2293: 2291:VoIP recording 2288: 2283: 2278: 2276:Voice over LTE 2273: 2268: 2263: 2258: 2253: 2248: 2243: 2238: 2233: 2228: 2223: 2218: 2213: 2208: 2202: 2200: 2197: 2196: 2195: 2188: 2187: 2186: 2180: 2170: 2159: 2148: 2145: 2138: 2131: 2128: 2121: 2110: 2109: 2108: 2101: 2098:wideband audio 2079: 2058: 2048: 2037: 2036: 2035: 2029: 2026: 2013: 2012: 2011: 1997: 1994:Internet Phone 1984: 1978: 1971: 1963: 1956: 1953: 1947:Voice over ATM 1943: 1940:Bishnu S. Atal 1928: 1917: 1910: 1895: 1876: 1875:encoded voice. 1857: 1850: 1839: 1818: 1815: 1813:to telephony. 1811:cloud services 1762:Bishnu S. Atal 1691:digital speech 1655:packet network 1650: 1647: 1615:Interconnected 1594: 1591: 1574: 1571: 1570: 1569: 1566: 1558: 1551: 1548: 1545: 1525: 1522: 1485: 1482: 1473: 1470: 1461: 1458: 1456: 1450: 1442:European Union 1437: 1436:European Union 1434: 1417: 1414: 1389: 1388: 1369: 1367: 1360: 1354: 1351: 1346: 1343: 1330: 1327: 1318: 1315: 1272:point-to-point 1181: 1178: 1152: 1149: 1145:data integrity 1116: 1113: 1053: 1050: 1023: 1020: 968: 967: 926: 924: 917: 911: 908: 891: 888: 887: 886: 879:coaxial cables 860: 850: 828:physical layer 819: 816: 780: 777: 706:playout buffer 641:problems with 628: 625: 586: 583: 560: 557: 540: 537: 497: 494: 475: 472: 471: 470: 463: 452: 417: 414: 412: 409: 408: 407: 404:Skype protocol 401: 395: 389: 379: 369: 363: 357: 351: 345: 339: 333: 327: 325:videotelephony 310: 309: 303: 293: 287: 281: 269: 259: 238:open standards 229: 226: 203:federated VoIP 88: 85: 40:sessions over 15: 13: 10: 9: 6: 4: 3: 2: 6954: 6943: 6940: 6938: 6935: 6933: 6930: 6928: 6925: 6923: 6922:Voice over IP 6920: 6919: 6917: 6902: 6894: 6892: 6884: 6882: 6874: 6872: 6862: 6861: 6858: 6851: 6847: 6845: 6842: 6840: 6837: 6835: 6832: 6830: 6827: 6823: 6820: 6818: 6815: 6814: 6812: 6810: 6807: 6806: 6804: 6800: 6794: 6791: 6789: 6786: 6784: 6781: 6779: 6776: 6774: 6771: 6769: 6766: 6764: 6761: 6759: 6756: 6754: 6751: 6749: 6746: 6745: 6743: 6741: 6737: 6731: 6728: 6726: 6723: 6721: 6718: 6716: 6713: 6711: 6708: 6706: 6703: 6701: 6698: 6696: 6693: 6691: 6688: 6686: 6683: 6681: 6678: 6676: 6673: 6671: 6668: 6667: 6665: 6663: 6659: 6653: 6650: 6648: 6645: 6643: 6640: 6638: 6635: 6633: 6630: 6629: 6627: 6623: 6617: 6616:Code-division 6614: 6612: 6609: 6607: 6604: 6602: 6601:Time-division 6599: 6597: 6594: 6592: 6589: 6588: 6586: 6584: 6580: 6574: 6571: 6567: 6564: 6562: 6559: 6558: 6557: 6554: 6550: 6547: 6546: 6545: 6542: 6540: 6537: 6535: 6532: 6531: 6529: 6527:and switching 6525: 6521: 6513: 6510: 6509: 6508: 6505: 6501: 6498: 6497: 6496: 6493: 6491: 6488: 6486: 6483: 6479: 6478:optical fiber 6476: 6475: 6474: 6471: 6469: 6468:Coaxial cable 6466: 6465: 6463: 6461: 6455: 6449: 6446: 6444: 6441: 6439: 6436: 6434: 6431: 6429: 6426: 6424: 6421: 6419: 6416: 6414: 6411: 6409: 6406: 6404: 6401: 6399: 6396: 6394: 6391: 6389: 6386: 6384: 6383:Radia Perlman 6381: 6379: 6376: 6374: 6371: 6369: 6366: 6364: 6361: 6359: 6356: 6354: 6351: 6349: 6346: 6344: 6341: 6339: 6336: 6334: 6331: 6329: 6326: 6324: 6321: 6319: 6316: 6314: 6311: 6309: 6306: 6304: 6301: 6299: 6296: 6294: 6291: 6289: 6286: 6284: 6281: 6279: 6276: 6274: 6273:Lee de Forest 6271: 6269: 6268:Thomas Edison 6266: 6264: 6261: 6259: 6258:Donald Davies 6256: 6254: 6251: 6249: 6246: 6244: 6243:Claude Chappe 6241: 6239: 6236: 6234: 6231: 6229: 6226: 6224: 6221: 6219: 6216: 6214: 6211: 6209: 6206: 6204: 6201: 6199: 6196: 6194: 6191: 6189: 6186: 6184: 6181: 6179: 6176: 6174: 6171: 6170: 6168: 6164: 6158: 6155: 6153: 6150: 6148: 6145: 6143: 6140: 6136: 6133: 6131: 6128: 6127: 6126: 6123: 6121: 6120: 6116: 6114: 6111: 6108: 6105: 6103: 6100: 6098: 6095: 6093: 6090: 6088: 6087:Smoke signals 6085: 6081: 6078: 6076: 6073: 6071: 6068: 6067: 6066: 6065:Semiconductor 6063: 6059: 6056: 6055: 6054: 6051: 6049: 6046: 6044: 6041: 6039: 6036: 6034: 6031: 6029: 6026: 6024: 6021: 6019: 6016: 6014: 6011: 6007: 6004: 6003: 6002: 5999: 5997: 5994: 5992: 5989: 5987: 5984: 5982: 5979: 5977: 5974: 5972: 5969: 5967: 5964: 5962: 5959: 5957: 5954: 5952: 5949: 5945: 5942: 5940: 5937: 5935: 5932: 5930: 5927: 5926: 5925: 5924:Digital media 5922: 5918: 5915: 5913: 5910: 5908: 5905: 5903: 5900: 5899: 5898: 5895: 5893: 5890: 5888: 5885: 5883: 5880: 5878: 5875: 5873: 5870: 5868: 5865: 5864: 5862: 5860: 5856: 5852: 5845: 5840: 5838: 5833: 5831: 5826: 5825: 5822: 5812: 5802: 5790: 5784: 5781: 5779: 5776: 5774: 5771: 5769: 5766: 5764: 5761: 5760: 5758: 5754: 5748: 5745: 5743: 5742:Nuisance call 5740: 5738: 5735: 5733: 5730: 5729: 5727: 5723: 5717: 5714: 5712: 5709: 5707: 5704: 5702: 5699: 5697: 5694: 5692: 5689: 5687: 5684: 5682: 5681:Fibre-optical 5679: 5677: 5674: 5672: 5669: 5668: 5666: 5662: 5656: 5653: 5651: 5648: 5647: 5645: 5641: 5635: 5632: 5630: 5627: 5625: 5622: 5620: 5617: 5615: 5612: 5611: 5609: 5605: 5601: 5594: 5589: 5587: 5582: 5580: 5575: 5574: 5571: 5559: 5556: 5554: 5553:Microblogging 5551: 5549: 5546: 5545: 5543: 5539: 5533: 5530: 5528: 5525: 5521: 5518: 5517: 5516: 5515:Voice over IP 5513: 5511: 5508: 5506: 5503: 5501: 5500:LAN messenger 5498: 5496: 5493: 5491: 5488: 5486: 5483: 5482: 5480: 5478: 5474: 5468: 5465: 5463: 5460: 5456: 5453: 5451: 5448: 5447: 5446: 5443: 5441: 5438: 5436: 5433: 5431: 5428: 5426: 5423: 5422: 5420: 5418: 5414: 5408: 5405: 5403: 5400: 5398: 5395: 5393: 5390: 5388: 5385: 5383: 5380: 5379: 5376: 5372: 5365: 5360: 5358: 5353: 5351: 5346: 5345: 5342: 5335: 5331: 5327: 5325:at Wiktionary 5324: 5323: 5317: 5313: 5312: 5308: 5298: 5293: 5289: 5285: 5278: 5275: 5271: 5267: 5264: 5260: 5256: 5253: 5248: 5245: 5233: 5229: 5222: 5219: 5206: 5200: 5197: 5193: 5189: 5186: 5181: 5178: 5166: 5162: 5155: 5152: 5147: 5145:9780470377864 5141: 5137: 5133: 5132: 5124: 5121: 5109: 5105: 5098: 5095: 5090: 5084: 5080: 5073: 5070: 5058: 5054: 5053: 5045: 5044: 5036: 5033: 5021: 5017: 5016: 5008: 5007: 4999: 4996: 4991: 4989:9780470023631 4985: 4981: 4977: 4976: 4968: 4965: 4952: 4948: 4942: 4939: 4926: 4920: 4917: 4904: 4898: 4895: 4892:, March 1996. 4891: 4885: 4882: 4869: 4863: 4860: 4847: 4841: 4838: 4835: 4831: 4828: 4825:June 2, 1997 4824: 4820: 4817: 4811: 4808: 4795: 4789: 4786: 4770: 4763: 4760: 4748:. Sunsite.edu 4744: 4738: 4735: 4723: 4719: 4715: 4714:Network World 4711: 4704: 4701: 4696: 4692: 4685: 4682: 4674:September 14, 4669: 4665: 4658: 4656: 4652: 4639: 4635: 4629: 4626: 4621: 4617: 4613: 4609: 4602: 4595: 4592: 4589: 4584: 4581: 4577: 4576: 4568: 4566: 4562: 4546: 4542: 4538: 4534: 4530: 4526: 4522: 4515: 4508: 4505: 4500: 4496: 4491: 4486: 4482: 4478: 4471: 4464: 4462: 4460: 4458: 4456: 4452: 4440: 4438:9781118909706 4434: 4430: 4429: 4422: 4419: 4406: 4405:"Danny Cohen" 4400: 4397: 4385: 4381: 4374: 4371: 4363:September 21, 4358: 4352: 4349: 4336: 4330: 4327: 4323: 4319: 4316: 4311: 4308: 4300:September 21, 4296: 4292: 4285: 4282: 4277: 4273: 4272: 4265: 4262: 4259: 4253: 4250: 4246: 4239:September 19, 4231: 4224: 4217: 4215: 4211: 4198: 4194: 4188: 4185: 4173: 4169: 4162: 4159: 4147: 4143: 4136: 4133: 4121: 4117: 4110: 4107: 4094: 4090: 4084: 4081: 4068: 4064: 4058: 4055: 4042: 4038: 4032: 4029: 4021:September 20, 4017: 4013: 4006: 4003: 3998: 3992: 3989: 3976: 3972: 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1660: 1656: 1648: 1646: 1644: 1640: 1635: 1633: 1629: 1625: 1620: 1616: 1613:Operators of 1611: 1609: 1605: 1601: 1593:United States 1592: 1590: 1588: 1584: 1580: 1572: 1567: 1564: 1559: 1552: 1549: 1546: 1543: 1542: 1541: 1538: 1535: 1534:VoIP gateways 1531: 1523: 1521: 1519: 1515: 1511: 1507: 1502: 1500: 1495: 1491: 1483: 1481: 1479: 1471: 1469: 1467: 1459: 1455: 1451: 1449: 1445: 1443: 1435: 1433: 1431: 1427: 1423: 1415: 1413: 1411: 1407: 1403: 1399: 1394: 1385: 1373: 1368: 1359: 1358: 1352: 1350: 1344: 1342: 1340: 1336: 1328: 1326: 1324: 1316: 1314: 1312: 1308: 1303: 1301: 1297: 1293: 1289: 1283: 1281: 1277: 1273: 1269: 1265: 1261: 1258:protocol for 1257: 1253: 1248: 1246: 1242: 1238: 1234: 1230: 1226: 1221: 1218: 1214: 1210: 1205: 1203: 1199: 1195: 1191: 1187: 1179: 1177: 1174: 1170: 1166: 1161: 1158: 1150: 1148: 1146: 1140: 1138: 1133: 1128: 1126: 1122: 1114: 1112: 1110: 1106: 1102: 1098: 1093: 1091: 1087: 1082: 1079: 1075: 1070: 1068: 1062: 1059: 1051: 1049: 1045: 1043: 1038: 1036: 1032: 1028: 1021: 1019: 1017: 1012: 1010: 1006: 1002: 998: 994: 990: 986: 982: 978: 975: 964: 961: 953: 950:November 2019 943: 939: 933: 932: 927:This section 925: 921: 916: 915: 909: 907: 905: 901: 897: 889: 884: 880: 876: 872: 868: 865: 861: 858: 854: 851: 848: 844: 840: 837: 836: 835: 833: 829: 825: 817: 815: 811: 809: 805: 801: 797: 792: 790: 786: 778: 776: 774: 769: 765: 760: 758: 754: 750: 746: 742: 737: 735: 731: 727: 723: 717: 715: 711: 707: 703: 702:queuing delay 699: 694: 692: 688: 682: 679: 675: 671: 667: 662: 660: 656: 650: 648: 644: 639: 635: 626: 624: 622: 617: 615: 610: 606: 604: 595: 591: 584: 582: 578: 576: 571: 569: 565: 558: 556: 554: 550: 545: 538: 536: 534: 530: 527: 522: 520: 516: 510: 508: 504: 496:Corporate use 495: 493: 491: 487: 485: 481: 473: 467: 464: 461: 457: 453: 450: 446: 442: 441: 440: 437: 435: 431: 422: 415: 410: 405: 402: 399: 396: 393: 390: 387: 383: 380: 377: 373: 370: 367: 364: 361: 358: 355: 352: 349: 346: 343: 340: 337: 334: 331: 328: 326: 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Retrieved 5232:AppleInsider 5221: 5209:. Retrieved 5199: 5180: 5168:. Retrieved 5164: 5154: 5130: 5123: 5111:. Retrieved 5107: 5097: 5078: 5072: 5060:. Retrieved 5050: 5042: 5035: 5023:. Retrieved 5013: 5005: 4998: 4974: 4967: 4955:. Retrieved 4951:the original 4941: 4929:. Retrieved 4919: 4907:. Retrieved 4897: 4889: 4884: 4872:. Retrieved 4862: 4850:. Retrieved 4840: 4810: 4798:. Retrieved 4788: 4776:. Retrieved 4762: 4750:. Retrieved 4737: 4727:February 10, 4725:. Retrieved 4713: 4703: 4694: 4684: 4672:. Retrieved 4667: 4642:. Retrieved 4638:the original 4628: 4611: 4607: 4594: 4583: 4572: 4552:. Retrieved 4545:the original 4524: 4520: 4507: 4480: 4476: 4442:. Retrieved 4427: 4421: 4409:. Retrieved 4399: 4387:. Retrieved 4383: 4373: 4361:. Retrieved 4351: 4339:. Retrieved 4329: 4310: 4298:. Retrieved 4294: 4284: 4276:the original 4270: 4264: 4252: 4244: 4237:. Retrieved 4230:the original 4201:. Retrieved 4196: 4187: 4175:. Retrieved 4172:The National 4171: 4161: 4149:. 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Zakon 4868:"RFC 2235" 4341:August 16, 4177:January 9, 4151:January 9, 4125:January 9, 3827:VOIPSA.org 3176:October 4, 2513:1709.01320 2379:References 2135:PhoneGnome 2045:softswitch 1919:1985: The 1899:Jon Postel 1852:1974: The 1817:Milestones 1787:Alon Cohen 1659:Paul Baran 1499:Change.org 1382:April 2022 1264:softphones 1067:IP address 1029:(LNP) and 743:(QoS) and 134:(LPC) and 113:narrowband 6927:Broadband 6813:Americas 6802:Locations 6773:Internet2 6534:Bandwidth 6238:Vint Cerf 6135:streaming 6113:Telephone 6053:Semaphore 5944:streaming 5747:Phone tag 5655:Caller ID 5600:Telephony 5450:Textboard 5211:March 31, 4752:April 29, 4722:0887-7661 4541:212485331 4533:2277-128X 4499:1932-8346 4203:March 26, 4146:Gulf News 3981:April 29, 3666:CiteSeerX 2981:1089-7089 2894:March 16, 2530:1932-4537 2426:March 19, 2107:standard. 2067:develops 2025:standard. 2008:Radvision 2004:Microsoft 1992:releases 1951:StrataCom 1907:Vint Cerf 1717:(LPC), a 1709:of early 1707:bandwidth 1610:(CALEA). 1412:company. 1323:caller ID 1317:Caller ID 1311:endpoints 1280:Wireshark 1225:firewalls 1105:VoIP E911 1058:land line 902:, packet 898:, packet 466:Softphone 388:instances 376:WebSocket 273:Signaling 256:transport 228:Protocols 178:, and an 158:(used in 150:(used in 142:(used in 93:telephony 6881:Category 6768:Internet 6758:CYCLADES 6675:Ethernet 6625:Concepts 6549:terminal 6500:wireless 6323:Bob Kahn 6166:Pioneers 5991:Internet 5882:Cable TV 5614:Landline 5527:Web chat 5266:Archived 5255:Archived 5188:Archived 4830:Archived 4819:Archived 4796:. iLocus 4389:March 2, 4318:Archived 4041:BBC News 3941:April 7, 3741:June 12, 3711:June 12, 3640:Archived 3614:Archived 3530:April 5, 3525:CircleID 3452:July 19, 3387:July 19, 3381:Archived 3186:cite web 2989:12336090 2872:March 3, 2846:March 2, 2811:Archived 2764:June 21, 2691:cite web 2681:April 8, 2651:cite web 2641:April 8, 2598:July 19, 2286:VoIP VPN 2281:VoiceXML 2199:See also 2175:Rise of 2167:FaceTime 2114:INOC-DBA 2069:Asterisk 1990:VocalTec 1975:VocalTec 1779:VocalTec 1774:Internet 1695:bit rate 1518:FaceTime 1510:WhatsApp 1406:Ethiopia 1398:captured 1180:Security 1119:Sending 883:contract 857:Ethernet 659:DiffServ 594:Asterisk 480:backhaul 445:Ethernet 411:Adoption 306:Security 224:system. 152:WhatsApp 144:FaceTime 87:Overview 83:(POTS). 46:Internet 6901:Commons 6891:Outline 6844:Oceania 6763:FidoNet 6748:ARPANET 6561:circuit 6130:digital 5859:History 5435:FidoNet 5272:in PDF) 5237:June 9, 4848:. 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