Voice over IP - Knowledge (XXG)

1656:. 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. 1600:(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. 1055:(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. 1044:(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 1455:, 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). 809:(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, 601: 786:(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. 5817: 1374: 5341: 5327: 6888: 1289:. 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 931: 6898: 1479:, 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. 6877: 5807: 739:. 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 6908: 1592:, 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 1114:. 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 620:

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.

1419:, 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 528:. 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 208:, 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 1103:(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. 1296:

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

1816:(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 781:

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

616:), 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. 2443:

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

349:, 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. 634:, 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. 1048:(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. 523:

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

546:, 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. 432: 1187:

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

1800:, 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 1075:

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

447:. 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. 4585: 1547:

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

319:– 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. 1507:

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

647:(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 1579:

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.

1150:(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. 1360:

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

443:, 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 892:). 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 287:– Performing registration (advertising one's presence and contact information) and discovery (locating someone and obtaining their contact information), dialing (including reporting 5052: 715:

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

3202: 1576:(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. 675:

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.

2791: 1864: 1618: 1018:. 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 1002:

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.

5365: 3737: 1111: 4280: 4233: 802:(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. 532:

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.

4268: 402: 269:– Creating reliable transmission over unreliable protocols, which may involve acknowledging receipt of data and retransmitting data that wasn't received. 3580: 3261:"RFC 3969– The Internet Assigned Number Authority (IANA) Uniform Resource Identifier (URI) Parameter Registry for the Session Initiation Protocol (SIP)" 1503:(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 520:

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

1320:(NSA) released comprehensive documents describing the four attack planes of a communications system – the network, perimeter, session controllers and 1080:

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

5358: 3665: 4073: 3180: 216:. These solutions typically allow dynamic interconnection between users in any two domains of the Internet, when a user wishes to place a call. 6854: 5051:

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

4126: 1255: 297:– 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.). 4826: 4178: 1203:

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

6849: 6839: 6819: 6621: 5097: 4203: 3698: 3337: 2226: 1653: 4239:. New Delhi India: Telecom Regulatory Authority of India (TRAI). p. 16 (Section 2.2.1.2 PC–to–Phone Internet telephony). Archived from 122:. Various codecs exist that optimize the media stream based on application requirements and network bandwidth; some implementations rely on 2422: 630:

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

370: 4674: 4644: 4328: 3935: 3037: 279:(sometimes glossed as simply a "call"), which is a connection between two or more peers that provides a context for further communication. 5265: 4234:"Telecom Regulatory Authority of India (TRAI) Consultation paper on Issues related to Internet Telephony. Consultation Paper No. 11/2008" 2158:

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

6844: 6690: 5701: 5601: 3810: 1573: 1313:. Public Secure VoIP is also available with free GNU software and in many popular commercial VoIP programs via libraries, such as ZRTP. 1298: 1282: 1262: 1196: 1100: 376: 5276: 5171: 4390: 1920:

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.

361:, control protocol for media gateways across a converged internetwork consisting of the traditional PSTN and modern packet networks 223:, VoIP is also available on many personal computers and other Internet access devices. Calls and SMS text messages may be sent via 3850: 3016: 106:

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

6947: 6495: 6043: 5845: 5696: 3767: 3624: 2681: 2071: 1820:, fueled widespread interest and entrepreneurship in voice-over-IP services, applying new Internet technology paradigms, such as 1638: 3556: 3353: 1645:

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

860:(MAC) layer. The standard is considered of critical importance for delay-sensitive applications, such as voice over wireless IP. 291:), negotiating capabilities, and call control (such as hold, mute, transfer/forwarding, dialing DTMF keys during a call , etc.). 6606: 5381: 2847: 2795: 558:

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.

6601: 6152: 5721: 3557:"Internet Protocol Telephony & Voice over Internet Protocol Security Technical Implementation Guide Version 2, Release 2" 1942: 1913: 1846: 1764: 1744: 952: 948: 517: 352: 283: 5238: 2764: 1118:

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.

704:. But since every packet must contain protocol headers, this increases relative header overhead on every link traversed. 6901: 6662: 6559: 6102: 5869: 5417: 4857:"H.323 Visual telephone systems and equipment for local area networks which provide a non-guaranteed quality of service" 4481:"A History of Realtime Digital Speech on Packet Networks: Part II of Linear Predictive Coding and the Internet Protocol" 2949: 382: 364: 4582:

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

340: 91: 3745: 4286: 4240: 3650: 627:. For remote and external endpoints, available connectivity options mirror those of Hosted or Cloud VoIP solutions. 6750: 6672: 6611: 6318: 3478: 2445: 1597: 1593: 1239: 995: 806: 795: 276: 941: 6952: 6522: 6483: 6328: 6228: 6157: 6090: 5917: 5691: 5427: 5298: 5067: 5030: 4555: 2093: 1243: 1212: 1041: 719:, deliberately increasing latency to improve the chance that each packet will be on hand when it is time for the 701: 440: 4007: 3967: 6881: 6123: 6058: 6011: 5897: 5811: 5686: 5487: 1902: 1834: 1760: 1725: 1610: 1464: 1317: 1286: 1270: 1147: 1037: 984: 885: 736: 724: 665: 466: 142: 107: 4099: 3936:"The Road to Broadband Development in Developing Countries is through Competition Driven by Wireless and VOIP" 3098: 2821: 231:

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

6942: 6720: 6705: 6549: 6500: 6423: 6323: 6001: 5887: 5882: 5681: 5594: 5440: 2256: 2236: 2086: 1084: 743:. Most Internet backbone links are now so fast (e.g. 10 Gbit/s) that their delays are dominated by the 697: 513: 392: 111: 4957: 3531: 917:(delay), post-dial delay, and echo. The metrics are determined by VoIP performance testing and monitoring. 6932: 6642: 6428: 6243: 6188: 6183: 5996: 5961: 5412: 5407: 5402: 5215: 3676: 2261: 2051: 1898: 1871: 1857: 1756: 1686: 1678: 1321: 1166:

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

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

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

114:. They transport media streams using special media delivery protocols that encode audio and video with 5344: 5114: 4913: 4804: 1491:

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

794:

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

623:

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

4990: 3068: 2505:

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

2449: 2221: 2083: 1946: 1768: 1500: 1223: 857: 759: 244: 4204:"UAE loosens some VoIP restrictions as residents in lockdown call for end to WhatsApp and Skype ban" 1551:

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.

1029:

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.

190: 158: 48: 3673:

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

1059:

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

6937: 6695: 6652: 6583: 6453: 6383: 6358: 6293: 6140: 5861: 5587: 5302: 4547: 3704: 3149: 2995: 2624: 2544: 2518: 1894: 1752: 1717: 1674: 1408: 1052: 1026: 1003: 889: 881: 842: 783: 751: 696:

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

6735: 6657: 6571: 6554: 6517: 6403: 6363: 6193: 6162: 6028: 5922: 5821: 5660: 5520: 5500: 5495: 5397: 5262: 5150: 5093: 4994: 4728: 4539: 4505: 4443: 3786:"NSA Releases Guidance on Securing Unified Communications and Voice and Video over IP Systems" 3694: 3333: 3327: 3196: 2987: 2701: 2661: 2536: 1842: 1740: 1614: 1516: 1420: 1306: 1297:

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.

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

303:– Transferring the actual media in the call, such as audio, video, text messages, files, etc. 6740: 6700: 6680: 6647: 6576: 6534: 6448: 6303: 6288: 6263: 6238: 6198: 6048: 5907: 5902: 5892: 5542: 5273: 4626: 4495: 3686: 3058: 2979: 2528: 2331: 1984:

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

774: 648: 5195: 5014:

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

3508: 2742: 385:(SDP), a syntax for session initiation and announcement for multi-media communications and 6368: 6223: 5991: 5954: 5639: 5629: 5280: 5269: 5242: 5202: 4844: 4833: 4415: 4332: 4022: 2898: 1634: 1411:

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

834: 653: 454:

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

83: 5966: 3837: 2039:

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

1246:

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

723:

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".

2131:

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

1804:

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

1387:

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

516:(PBX) lines installed internationally were VoIP. For example, in the United States, the 6566: 6438: 6413: 6373: 6343: 6218: 6053: 5939: 5793: 5778: 5747: 5455: 5062: 5025: 4532:

International Journal of Advanced Research in Computer Science and Software Engineering

2301: 2286: 2108: 2079: 1950: 1772: 1696:

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

1175: 1155: 838: 716: 676: 604: 462:. These are typically designed in the style of traditional digital business telephones. 414: 335: 252: 213: 5326: 5293:

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.

6926: 6715: 6488: 6478: 6393: 6283: 6278: 6268: 6253: 6075: 5934: 5752: 5563: 5510: 4551: 3563: 3361: 2216: 2101: 1821: 1793: 1729: 1701: 1247: 1015: 712: 248: 138: 131: 127: 110:, the digital information is packetized and transmission occurs as IP packets over a 2999: 1512:

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

6593: 6433: 6378: 6308: 6273: 6208: 6107: 6097: 5949: 5634: 3981: 3427: 3383: 2920: 2548: 2276: 2251: 1966:

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

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

5350: 3708: 3282: 1867:(IEEE) publishes a paper entitled "A Protocol for Packet Network Interconnection". 817:, carry Ethernet without intermediate ATM/AAL5 layers, and they generally support 417:, proprietary Internet telephony protocol suite based on peer-to-peer architecture 373:(RTCP), sister protocol for RTP providing stream statistics and status information 4856: 4345: 4269:

Technical Note on Illegal International Long Distance telephone Exchange in India

2768: 1889:

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

821:

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

6793: 6443: 6353: 6338: 6298: 6258: 6117: 5742: 5392: 4837: 4701: 3071: 3052: 2366: 2266: 1977: 1970: 1649: 1589: 1345: 1179: 930: 906: 863: 853: 818: 778: 680: 585: 500: 470: 331: 228: 209: 119: 115: 3690: 2506: 6798: 6505: 6203: 6112: 6068: 6038: 6016: 6006: 5981: 5644: 5465: 4630: 4598: 2532: 2173: 2145: 2055: 1909: 1805: 1797: 1669: 1167: 1077: 1025:

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

220: 123: 44: 5054:

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

4732: 4543: 4509: 3581:"Secure Voice over IP (SVoIP) vs. Voice over Secure IP (VoSIP) Installations" 2991: 2540: 1969:

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

405:(XMPP), instant messaging, presence information, and contact list maintenance 6783: 6248: 6063: 5757: 5665: 5610: 5477: 5460: 2018: 2014: 1961: 1917: 1613:; make service accessible to people with disabilities; pay regulatory fees, 1333: 1324:– and explaining security risks and mitigation techniques for each of them. 1290: 1274: 1115: 1068: 476: 386: 103: 17: 4301: 1215:, may eliminate the need for personnel to greet and switch incoming calls. 5331: 4480: 3217:"RFC 3824– Using E.164 numbers with the Session Initiation Protocol (SIP)" 431: 27:

Methods of delivering voice communications and multimedia over IP networks

6778: 6768: 6685: 6510: 6333: 5624: 5537: 3811:"Deploying Secure Unified Communications/Voice and Video over IP Systems" 3260: 3216: 2296: 2291: 2177: 2124: 2000: 1985: 1960:, in addition to commercial packet voice products from companies such as 1789: 1784: 1705: 1528: 1520: 1416: 867: 669: 455: 310: 174: 162: 154: 56: 4878: 3150:"Performance and Stress Testing of SIP Servers, Clients and IP Networks" 762:(RTCP) extended reports, SIP RTCP summary reports, H.460.9 Annex B (for 6773: 6758: 5445: 4500: 3183:. ixc.ua. May 20, 2011. Archived from the original on November 11, 2012 2983: 2688:. Total Telecom Online. Archived from the original on February 17, 2006 2379: 2281: 2152: 2105: 1981:

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

1875: 1690: 1310: 1204: 955: in this section. Unsourced material may be challenged and removed. 4935: 1141:

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

555:

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

6803: 6763: 6085: 5877: 5830: 5515: 5450: 4179:"Etisalat launches new calling app plan days after Skype disruptions" 3354:"Keeping your telephone number when you change your service provider" 3305:"Application-level Network Interoperability and the Evolution of IMS" 3063: 2187: 2165:

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

2115: 2075: 1935: 1721: 1432: 1412: 1219: 910: 657: 150: 4586:

International Conference on Acoustics, Speech, and Signal Processing

4232:

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

3038:"Optical Packet Buffers for Backbone Internet Routers | Request PDF" 2584: 2021:

initiated standardization activities for VoIP communications system.

1242:, used to interconnect to transit networks or the Internet. Private 750:

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

309:– Providing out-of-band content or feedback about the media such as 5307: 3486: 2817: 2523: 6788: 6725: 6033: 5435: 3133:"Voice over IP (VoIP) Performance Evaluation on VMware vSphere® 5" 2166: 2135: 2042: 2033: 2029: 2010: 1992: 1957: 1809: 1540: 1524: 1504: 1440: 1278: 1135: 999: 991: 874: 814: 767: 763: 700:(DSL), is to reduce the maximum transmission time by reducing the 599: 543: 529: 459: 430: 358: 346: 224: 205: 198: 186: 182: 178: 170: 149:(MDCT) compression methods. Popular codecs include the MDCT-based 4721:"Network World - Startup targets desktop Videoconferencing arena" 6730: 5568: 5558: 4961: 4439:

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

3851:"Hearing Aid Compatibility for Wireline and Wireless Telephones" 2193: 2162: 2155:

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

1924: 1883: 1763:. LPC has since been the most widely used speech coding method. 1747:(NTT) in 1966. LPC was capable of speech compression down to 2.4 1476: 1302: 1266: 1251: 1142: 877: 810: 194: 166: 5834: 5583: 5354: 3912: 3666:"Packet loss concealment in a secure voice over IP environment" 3664:

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

3454:"Keep your VoIP E911 service in compliance with this checklist" 1195:

Secure calls are possible using standardized protocols such as

988:

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

5976: 5773: 3768:"Secure VOIP calling, free software, and the right to privacy" 3617:

International Journal of Computer Science and Network Security

2743:"Learn to Make Free or Inexpensive Calls Using SIP on Android" 2337: 1367: 1131: 924: 631: 624: 251:

in applications such as VoIP phones, mobile applications, and

79: 75: 4719:

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

4525:"Application of MFCC in Text Independent Speaker Recognition" 4127:"Etisalat launches new unlimited calling plan with VoIP apps" 2148:

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

5579: 3840:, Blog: "Hello Mom, I'm a Fake!" (Telespoof and Fakecaller). 3501:"4.4 VOIP – Regulatory Issues – Universal Service" 2114:

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

1051:

A voice call originating in the VoIP environment also faces

367:(RTP), transport protocol for real-time audio and video data 4983:

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

4702:"The History of VoIP Over the Last 55 Years (1966 to 2021)" 4367: 3986:

Canadian Radio-television and Telecommunications Commission

3875: 1628:

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

1437:

Canadian Radio-television and Telecommunications Commission

343:(SIP), connection management protocol developed by the IETF 4282:

Stars and Stripes: USFK deal keeps VoIP access for troops

1956:

1986: Proposals from various standards organizations for

1415:

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

773:

The RTCP extended report VoIP metrics block specified by

5272:

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

3116:"Methodology for SIP Infrastructure Performance Testing" 3086:

PacketCable Residential SIP Telephony Feature Definition

2648:. EE Times. Archived from the original on August 9, 2011 1211:

the existing data stream. Automated software, such as a

4391:"The State Of Cybersecurity Wiretapping's Fuzzy Future" 1519:. However, popular instant messaging applications like 197:, a codec that uses only 8 kbit/s each way called 5295:

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

5115:"State of the Art: Get Your Free Net Phone Calls Here" 2350: 1543:, it is legal to use VoIP, but it is illegal to have 994:

is a global numbering standard for both the PSTN and

535:

VoIP solutions aimed at businesses have evolved into

4227: 4225: 2340: 2334: 2190:

technology which supports VoIP directly in browsers.

2141:

2004: Commercial VoIP service providers proliferate.

2045:

speech codec introduced, using CELP (LPC) algorithm.

1596:

providing personal Internet services by contract to

6812: 6749: 6671: 6635: 6592: 6533: 6467: 6176: 5868: 5766: 5735: 5674: 5653: 5617: 5551: 5486: 5426: 3889:"network infrastructure: getting started with VoIP" 3099:"VoIP performance measurement using QoS parameters" 2511:

IEEE Transactions on Network and Service Management

2382:

can be used for DSL connectivity without using ATM.

1568:, no other form of Internet Telephony is permitted. 1174:VoIP phones and VoIP telephone adapters connect to 4612:"A Protocol for Packet Network Intercommunication" 1893:kpbs LPC, between Culler-Harrison Incorporated in 1767:(CELP), a type of LPC algorithm, was developed by 4805:"The 10 that Established VOIP (Part 1: VocalTec)" 4647:. The National Science Foundation. Archived from 3790:National Security Agency/Central Security Service 2818:"Social Security to Build "World's Largest VOIP"" 2507:"OpenSIP: Toward Software-Defined SIP Networking" 1991:1994: MTALK, a freeware LAN VoIP application for 1865:Institute of Electrical and Electronics Engineers 1619:Communications Assistance for Law Enforcement Act 1261:Standards for securing VoIP are available in the 5172:"Prospects bright for voice calls over internet" 4914:"The 10 that Established VOIP (Part 2: Level 3)" 4675:"VoIP Basics: Everything Beginners Should Know!" 3201:: CS1 maint: bot: original URL status unknown ( 3088:, Technical Report, PKT-TR-RST-V03-071106 (2007) 2205:codec introduced, using MDCT and LPC algorithms. 1010:(usernames) whereas SIP implementations can use 355:(MGCP), connection management for media gateways 3121:. Miroslav Voznak, Jan Rozhon. August 14, 2016. 3054:RTP Control Protocol Extended Reports (RTCP XR) 2841: 2839: 1878:in August 1974, carrying barely intelligible 16 3608:Dunte, Markus; Ruland, Christoph (June 2007). 3011: 3009: 2921:"VoIP - Vulnerability over Internet Protocol?" 2423:"Voice Over IP : Protocols and Standards" 1945:(CELP), a type of LPC algorithm, developed by 1332:Voice over IP protocols and equipment provide 1182:which typically depend on the availability of 5846: 5595: 5366: 5092:. Los Alamitos: IEEE Computer Society Press. 3738:"Cellcrypt secure VOIP heading to BlackBerry" 1808:became available, and new protocols, such as 1112:Wireless Communications and Public Safety Act 435:Example of residential network including VoIP 8: 4936:"RFC 2543, SIP: Session Initiation Protocol" 4578: 4576: 4153:"No Skype? Pay Dh50 monthly for video calls" 4074:"Saudi Arabia to lift ban on internet calls" 4048:"Saudi Arabia to lift ban on internet calls" 3417:"FCC Consumer Advisory VoIP and 911 Service" 2642:"WIRELESS: Carriers look to IP for backhaul" 2448:and the common encryption mechanism used is 2321:Variously pronounced as individual letters, 2180:, which uses the LD-MDCT-based AAC-LD codec. 1348:compatibility requirements set forth by the 1250:devices involve assistive protocols such as 43:, is a method and group of technologies for 6861:Global telecommunications regulation bodies 4938:. Handley, Schulzrinne, Schooler, Rosenberg 1293:, facilitate capturing VoIP conversations. 6897: 5853: 5839: 5831: 5602: 5588: 5580: 5373: 5359: 5351: 4589:(ICASSP), vol. 10, pp. 937–940, 1985. 3532:"Examining Two Well-Known Attacks on VoIP" 3181:"Importance of Softswitch VoIP Technology" 2794:. Government Computer News. Archived from 998:(PLMN). Most VoIP implementations support 411:, for peer-to-peer session control in XMPP 403:Extensible Messaging and Presence Protocol 5306: 5239:"Inside iPhone 4: FaceTime video calling" 4785:. Computer Telephony Interaction Magazine 4499: 3680: 3384:"TelePassport takes the sting out of MNP" 3062: 2522: 2068:(SIP) specification RFC 2543 is released. 971:Learn how and when to remove this message 683:. This signals a transport protocol like 86:) over the Internet, rather than via the 4125:Debusmann, Bernd Jr. (January 9, 2018). 3263:. The Internet Society. December 1, 2004 2944: 2942: 2940: 2938: 2936: 2934: 243:Voice over IP has been implemented with 4474: 4472: 4470: 4468: 4466: 4302:"Cybertelecom :: VoIP :: FCC" 4023:"Oman cuffs 212 for selling VoIP calls" 3641:Stringfellow, Brian (August 15, 2001). 3452:Noworatzky, Daniel (February 6, 2019). 3164:"Testing Voice over IP (VolP) Networks" 2846:Korzeniowski, Peter (January 8, 2009). 2395: 2314: 2196:codec introduced, using MDCT algorithm. 1199:. Most of the facilities of creating a 613: 439:Mass-market VoIP services use existing 4668: 4666: 4100:"Don't worry, Skype is working in UAE" 3562:. DISA. April 21, 2006. Archived from 3411: 3409: 3194: 3017:"Quality of Service for Voice over IP" 2950:"Quality of Service for Voice over IP" 2699: 2659: 2365:IP networks may also be more prone to 1256:Interactive Connectivity Establishment 1092:roaming via another cellular company. 727:, i.e. momentary audio interruptions. 5170:Remo, Michelle V. (August 27, 2007). 4368:"Voice Over Internet Protocol (VoIP)" 4177:Zacharias, Anna \ (January 8, 2018). 3988:. Government of Canada. April 4, 2005 2848:"Three Technologies You Need In 2009" 2599:"Voice Over Internet Protocol (VoIP)" 2227:Comparison of audio network protocols 1735:algorithm that was first proposed by 1654:Foreign Intelligence Surveillance Act 1641:via wholesale carriers. Providers of 1285:VoIP at the transport level by using 983:A VoIP media gateway controller (aka 7: 6907: 5218:. Wirevolution.com. January 13, 2009 5142:VoIP Voice and Fax Signal Processing 3630:from the original on April 19, 2023. 3219:. The Internet Society. June 1, 2004 3104:. A.H.Muhamad Amin. August 14, 2016. 2872:Callahan, Renee (December 9, 2008). 1652:is debating concerns changes to the 1099:(SIP) registrar. In such cases, the 953:adding citations to reliable sources 758:(QoE) for VoIP calls. These include 371:Real-time Transport Control Protocol 5237:Daniel Eran Dilger (June 8, 2010). 4619:IEEE Transactions on Communications 3878:, What are some advantages of VoIP? 2421:Arora, Rakesh (November 23, 1999). 2007:commercial Internet phone software. 1724:. The solution to this problem was 1574:Internet Assigned Numbers Authority 1263:Secure Real-time Transport Protocol 1197:Secure Real-time Transport Protocol 1101:Internet telephony service provider 584:Typically this will be one or more 377:Secure Real-time Transport Protocol 141:standards in VoIP are based on the 5216:"Skype's new super wideband codec" 4700:McCraw, Corey (October 12, 2022). 4151:Maceda, Cleofe (January 8, 2018). 3913:"Global VOIP Policy Status Matrix" 3653:from the original on June 1, 2023. 3394:from the original on July 19, 2022 2874:"Businesses Move To Voice-Over-IP" 2098:modified discrete cosine transform 1775:in 1985. LPC algorithms remain an 884:(LAN) using existing home wiring ( 833:Several protocols are used in the 147:modified discrete cosine transform 25: 5139:Nagireddi, Sivannarayana (2008). 3855:Federal Communications Commission 3675:. Vol. 1. pp. 415–419. 2824:from the original on June 2, 2009 2790:Jackson, William (May 27, 2009). 2603:Federal Communications Commission 1685:in 1973 which was developed into 1639:incumbent local exchange carriers 1555:PC to PC; within or outside India 1350:Federal Communications Commission 1309:on a classified network, such as 1046:Federal Communications Commission 485:PSTN and mobile network providers 88:public switched telephone network 6906: 6896: 6887: 6886: 6875: 6496:Free-space optical communication 5815: 5805: 5339: 5325: 5017:A guideline to audio codec delay 4389:Greenberg, Andy (May 15, 2008). 3530:Thermos, Peter (April 5, 2006). 2763:Michael Dosch and Steve Church. 2330: 1689:which operated across the early 1564:Except whatever is described in 1372: 929: 852:is an approved amendment to the 379:(SRTP), encrypted version of RTP 5382:Computer-mediated communication 5113:Pogue, David (August 2, 2007). 4610:Cerf, V.; Kahn, R. (May 1974). 3982:"Telecom Decision CRTC 2005-21" 3152:. StarTrinity. August 13, 2016. 2054:began development of its first 1712:kbps, much greater than the 2.4 1022:(ENUM) service in IMS and SIP. 940:needs additional citations for 5263:Presentation of the CELT codec 4960:. Asterisk.org. Archived from 4727:. IDG Network World Inc: 39–. 4442:. Willey. September 19, 2014. 3968:"VOICE OVER INTERNET PROTOCOL" 2765:"VoIP in the Broadcast Studio" 1943:Code-excited linear prediction 1914:Information Sciences Institute 1847:Nippon Telegraph and Telephone 1765:Code-excited linear prediction 1745:Nippon Telegraph and Telephone 1677:of the mid-twentieth century. 518:Social Security Administration 353:Media Gateway Control Protocol 1: 5330:The dictionary definition of 5088:Stapleton-Gray, Ross (2009). 3283:"Your personal online number" 2408:Cambridge Dictionaries Online 2242:High Bit Rate Media Transport 2058:, a term they coined in 1998. 1681:first demonstrated a form of 1648:Another legal issue that the 1637:and exchange of traffic with 1006:allows subscribers to choose 896:with the network controllers. 735:, jitter can be modeled as a 607:-based PBX for small business 395:(IAX), protocol used between 6882:Telecommunication portal 6663:Telecommunications equipment 5812:Telecommunication portal 5418:Virtual learning environment 5347:travel guide from Wikivoyage 4488:Found. Trends Signal Process 3332:. Cisco Press. p. 557. 2767:. Axia Audio. Archived from 1934:commissions the creation of 1305:. Secure voice over IP uses 473:have this function built in. 383:Session Description Protocol 365:Real-time Transport Protocol 33:Voice over Internet Protocol 6399:Alexander Stepanovich Popov 5531:Voice chat in online gaming 4673:Dua, Amit (July 29, 2021). 3588:General Dynamics C4 Systems 2972:Bell Labs Technical Journal 2563:"H.323 and SIP Integration" 2232:Comparison of VoIP software 2127:, the first inter-provider 2066:Session Initiation Protocol 1932:National Science Foundation 1814:Session Initiation Protocol 1779:in modern VoIP technology. 1364:Regulatory and legal issues 1240:network address translators 1097:Session Initiation Protocol 1067:A telephone connected to a 1020:E.164 number to URI mapping 1012:Uniform Resource Identifier 341:Session Initiation Protocol 92:plain old telephone service 55:(IP) networks, such as the 6969: 6103:Telecommunications history 5201:February 10, 2013, at the 4780:"Internet Phone Release 4" 4523:Gupta, Shipra (May 2016). 3915:. Global IP Alliance. 2005 3691:10.1109/ACSSC.2004.1399165 3329:Packetcable Implementation 3307:. TMCnet.com. May 24, 2006 3138:. VMware. August 14, 2016. 2488:Library Technology Reports 2446:Layer 2 Tunneling Protocol 2100:(MDCT) is adopted for the 1664:The early developments of 1598:United States Forces Korea 1594:Internet service providers 1244:session border controllers 996:public land mobile network 807:virtual circuit identifier 796:Asynchronous Transfer Mode 275:– Creating and managing a 6870: 6711:Public Switched Telephone 6523:telecommunication circuit 6484:Fiber-optic communication 6229:Francis Blake (telephone) 6024:Optical telecommunication 5802: 5687:Communications satellites 5428:Asynchronous conferencing 5388: 5299:Audio Engineering Society 5176:Philippine Daily Inquirer 5068:Audio Engineering Society 5031:Audio Engineering Society 4832:October 30, 2013, at the 4631:10.1109/TCOM.1974.1092259 3479:"Faxing over IP networks" 2925:www.continuitycentral.com 2820:. Government Technology. 2706:: CS1 maint: unfit URL ( 2666:: CS1 maint: unfit URL ( 2533:10.1109/TNSM.2017.2741258 2096:(DCT) variant called the 2094:discrete cosine transform 1381:This section needs to be 1340:Hearing aid compatibility 1271:analog telephony adapters 1042:mobile number portability 845:. Some examples include: 770:.30 and MGCP extensions. 702:maximum transmission unit 441:broadband Internet access 212:, adopted the concept of 6622:Orbital angular-momentum 6059:Satellite communications 5898:Communications satellite 5488:Synchronous conferencing 5297:. 135th AES Convention. 5279:August 10, 2011, at the 5060:. 125th AES Convention. 5023:. 116th AES Convention. 4838:VoiP Developer Solutions 4584:Proceedings of the IEEE 4479:Gray, Robert M. (2010). 4335:, 47 C.F.R. pt. 9 (2007) 3169:. IXIA. August 14, 2016. 2467:. Google Talkabout. 2006 1927:is described in RFC 791. 1903:Lexington, Massachusetts 1835:Linear predictive coding 1761:Lexington, Massachusetts 1726:linear predictive coding 1611:local number portability 1318:National Security Agency 1287:opportunistic encryption 1148:analog telephone adapter 1038:Local number portability 737:Gaussian random variable 711:results from changes in 467:analog telephone adapter 323:VoIP protocols include: 253:web-based communications 143:linear predictive coding 108:circuit-switched network 6948:Audio network protocols 6501:Molecular communication 6324:Gardiner Greene Hubbard 6153:Undersea telegraph line 5888:Cable protection system 5682:Cable protection system 5441:Electronic mailing list 5268:August 7, 2011, at the 4916:. iLocus. July 13, 2007 4418:. INTERNET HALL of FAME 3505:ICT Regulation Tool Kit 2682:"Mobile's IP challenge" 2257:IP Multimedia Subsystem 2237:Differentiated services 2087:private branch exchange 1792:, based on a patent by 1281:is available to secure 1089:off-premises extensions 1085:virtual private network 798:(ATM) modems. They use 698:digital subscriber line 666:geostationary satellite 514:Private branch exchange 393:Inter-Asterisk eXchange 247:and protocols based on 130:, while others support 112:packet-switched network 72:broadband phone service 6643:Communication protocol 6429:Charles Sumner Tainter 6244:Walter Houser Brattain 6189:Edwin Howard Armstrong 5997:Information revolution 5413:Social network service 5408:Collaborative software 5403:Communication software 4843:June 16, 2011, at the 4708:. Fits Small Business. 4681:. Business 2 Community 4679:business2community.com 4645:"The Launch of NSFNET" 4346:"VoIP and 911 Service" 3934:Proenza, Francisco J. 3901:on September 17, 2011. 3772:Free Software Magazine 3643:"Secure Voice Over IP" 3610:"Secure Voice-over-IP" 3597:on September 24, 2015. 2792:"SSA goes big on VOIP" 2585:"Voice OVER IP (VOIP)" 2369:that cause congestion. 2262:List of VoIP companies 1908:1977: Danny Cohen and 1899:MIT Lincoln Laboratory 1872:Network Voice Protocol 1757:MIT Lincoln Laboratory 1687:Network Voice Protocol 1273:, as well as for some 800:ATM Adaptation Layer 5 709:Packet delay variation 608: 537:unified communications 445:direct inbound dialing 436: 233:unified communications 157:), the LPC/MDCT-based 90:(PSTN), also known as 6617:Polarization-division 6349:Narinder Singh Kapany 6314:Erna Schneider Hoover 6234:Jagadish Chandra Bose 6214:Alexander Graham Bell 5945:online video platform 5822:Telephones portal 5473:Bulletin board system 5147:John Wiley & Sons 4991:John Wiley & Sons 4331:June 8, 2010, at the 4267:Harish Kumar Gangwar 3489:on December 18, 2023. 3390:. November 13, 2006. 3239:"Create a Skype Name" 2378:Technologies such as 1777:audio coding standard 1704:packets, which had a 1698:pulse-code modulation 1110:(E911), based on the 756:quality of experience 733:central limit theorem 603: 434: 334:, voice over IP, and 245:proprietary protocols 193:voice codec known as 137:The most widely used 6459:Vladimir K. Zworykin 6419:Almon Brown Strowger 6389:Charles Grafton Page 6044:Prepaid mobile phone 5972:Electrical telegraph 5784:Telephone newspapers 4901:Recommendation G.729 4706:fitsmallbusiness.com 4538:(5): 805–810 (806). 4306:www.cybertelecom.org 4080:. September 20, 2017 4054:. September 20, 2017 3364:on December 12, 2009 3326:Jeff Riddel (2007). 2899:"Skype For Business" 2722:"Android SIP Client" 2450:Secure Sockets Layer 2222:Call-through telecom 1947:Manfred R. Schroeder 1769:Manfred R. Schroeder 1566:condition (ii) above 1501:United Arab Emirates 1495:United Arab Emirates 1224:VoIP vulnerabilities 1027:impedance mismatches 949:improve this article 858:media access control 760:RTP Control Protocol 596:Private VoIP systems 330:, open standard for 47:for the delivery of 6409:Johann Philipp Reis 6168:Wireless revolution 6130:The Telephone Cases 5987:Hydraulic telegraph 5707:Mobile phone signal 5506:Internet Relay Chat 5274:presentation slides 4964:on January 23, 2009 4561:on October 18, 2019 4370:. November 18, 2010 4348:. FCC. May 26, 2011 4289:on January 13, 2010 3569:on August 25, 2009. 2605:. November 18, 2010 2433:on January 19, 2024 2272:RTP payload formats 2247:Integrated services 2104:codec, used in the 1845:and Shuzo Saito of 1743:and Shuzo Saito of 1487:In September 2017, 1463:Arab states of the 1443:emergency service. 901:Performance metrics 784:mean opinion scores 656:, packet loss, and 570:Hosted VoIP systems 550:Delivery mechanisms 68:broadband telephony 49:voice communication 6607:Frequency-division 6584:Telephone exchange 6454:Charles Wheatstone 6384:Jun-ichi Nishizawa 6359:Innocenzo Manzetti 6294:Reginald Fessenden 6029:Optical telegraphy 5862:Telecommunications 5697:Free-space optical 5345:Internet telephony 5119:The New York Times 4958:"What is Asterisk" 4501:10.1561/2000000036 4246:on October 6, 2014 3857:. October 30, 2014 3433:on August 10, 2010 2984:10.1002/bltj.20077 2771:on October 7, 2011 1895:Goleta, California 1874:(NVP) tested over 1837:(LPC) proposed by 1753:Goleta, California 1675:telecommunications 1316:In June 2021, the 1222:with knowledge of 1162:Power requirements 1053:least-cost routing 1033:Number portability 1014:(URIs) similar to 888:, phone lines and 882:Local area network 843:network congestion 752:quality of service 645:quality of service 638:Quality of service 609: 526:personal computers 437: 313:, statistics, etc. 307:Quality of service 273:Session management 64:Internet telephony 62:The broader terms 6920: 6919: 6658:Store and forward 6653:Data transmission 6567:Network switching 6518:Transmission line 6364:Guglielmo Marconi 6329:Internet pioneers 6194:Mohamed M. Atalla 6163:Whistled language 5828: 5827: 5661:Answering machine 5577: 5576: 5521:Videoconferencing 5501:Instant messaging 5496:Data conferencing 5398:Online discussion 5099:978-0-7695-3568-5 4825:The free Library 4599:Audio Transceiver 4300:Pershing, Genny. 3818:media.defense.gov 3748:on April 24, 2009 3700:978-0-7803-8622-8 3339:978-1-58705-181-4 2686:www.totaltele.com 2465:"XMPP Federation" 1843:Nagoya University 1741:Nagoya University 1615:universal service 1517:COVID-19 pandemic 1421:telecommunication 1402: 1401: 1307:Type 1 encryption 1228:denial-of-service 1184:mains electricity 981: 980: 973: 805:Using a separate 612:QoS control (see 295:Media description 227:or the carrier's 165:), the LPC-based 128:compressed speech 53:Internet Protocol 16:(Redirected from 6960: 6953:Office equipment 6910: 6909: 6900: 6899: 6890: 6889: 6880: 6879: 6878: 6751:Notable networks 6741:Wireless network 6681:Cellular network 6673:Types of network 6648:Computer network 6535:Network topology 6449:Thomas A. Watson 6304:Oliver Heaviside 6289:Philo Farnsworth 6264:Daniel Davis Jr. 6239:Charles Bourseul 6199:John Logie Baird 5908:Data compression 5903:Computer network 5855: 5848: 5841: 5832: 5820: 5819: 5818: 5810: 5809: 5808: 5774:Fax transmission 5722:Submarine cables 5604: 5597: 5590: 5581: 5543:Web conferencing 5478:Online guestbook 5375: 5368: 5361: 5352: 5343: 5329: 5313: 5312: 5310: 5290: 5284: 5260: 5254: 5253: 5251: 5249: 5234: 5228: 5227: 5225: 5223: 5212: 5206: 5196:Audio-Mitschnitt 5193: 5187: 5186: 5184: 5182: 5167: 5161: 5160: 5136: 5130: 5129: 5127: 5125: 5110: 5104: 5103: 5085: 5079: 5078: 5076: 5074: 5059: 5048: 5042: 5041: 5039: 5037: 5022: 5011: 5005: 5004: 4980: 4974: 4973: 4971: 4969: 4954: 4948: 4947: 4945: 4943: 4932: 4926: 4925: 4923: 4921: 4910: 4904: 4897: 4891: 4890: 4888: 4886: 4875: 4869: 4868: 4866: 4864: 4853: 4847: 4823: 4817: 4816: 4814: 4812: 4801: 4795: 4794: 4792: 4790: 4784: 4775: 4769: 4768: 4766: 4764: 4758: 4750: 4744: 4743: 4741: 4739: 4716: 4710: 4709: 4697: 4691: 4690: 4688: 4686: 4670: 4661: 4660: 4658: 4656: 4641: 4635: 4634: 4616: 4607: 4601: 4596: 4590: 4580: 4571: 4570: 4568: 4566: 4560: 4554:. Archived from 4529: 4520: 4514: 4513: 4503: 4485: 4476: 4461: 4460: 4458: 4456: 4434: 4428: 4427: 4425: 4423: 4412: 4406: 4405: 4403: 4401: 4386: 4380: 4379: 4377: 4375: 4364: 4358: 4357: 4355: 4353: 4342: 4336: 4323: 4317: 4316: 4314: 4312: 4297: 4291: 4290: 4285:, archived from 4277: 4271: 4265: 4259: 4258: 4253: 4251: 4245: 4238: 4229: 4220: 4219: 4217: 4215: 4210:. March 26, 2020 4200: 4194: 4193: 4191: 4189: 4174: 4168: 4167: 4165: 4163: 4148: 4142: 4141: 4139: 4137: 4131:Arabian Business 4122: 4116: 4115: 4113: 4111: 4096: 4090: 4089: 4087: 4085: 4070: 4064: 4063: 4061: 4059: 4044: 4038: 4037: 4035: 4033: 4018: 4012: 4011: 4004: 3998: 3997: 3995: 3993: 3978: 3972: 3971: 3964: 3958: 3957: 3955: 3953: 3947: 3941:. Archived from 3940: 3931: 3925: 3924: 3922: 3920: 3909: 3903: 3902: 3900: 3894:. Archived from 3893: 3885: 3879: 3873: 3867: 3866: 3864: 3862: 3847: 3841: 3835: 3829: 3828: 3826: 3824: 3815: 3807: 3801: 3800: 3798: 3796: 3782: 3776: 3775: 3764: 3758: 3757: 3755: 3753: 3744:. Archived from 3742:Networkworld.com 3734: 3728: 3727: 3725: 3723: 3717: 3711:. Archived from 3684: 3670: 3661: 3655: 3654: 3638: 3632: 3631: 3629: 3614: 3605: 3599: 3598: 3596: 3590:. Archived from 3585: 3577: 3571: 3570: 3568: 3561: 3553: 3547: 3546: 3544: 3542: 3527: 3521: 3520: 3518: 3516: 3507:. Archived from 3497: 3491: 3490: 3485:. Archived from 3475: 3469: 3468: 3466: 3464: 3449: 3443: 3442: 3440: 3438: 3432: 3426:. Archived from 3421: 3413: 3404: 3403: 3401: 3399: 3380: 3374: 3373: 3371: 3369: 3360:. Archived from 3350: 3344: 3343: 3323: 3317: 3316: 3314: 3312: 3301: 3295: 3294: 3292: 3290: 3279: 3273: 3272: 3270: 3268: 3257: 3251: 3250: 3248: 3246: 3235: 3229: 3228: 3226: 3224: 3213: 3207: 3206: 3200: 3192: 3190: 3188: 3177: 3171: 3170: 3168: 3160: 3154: 3153: 3146: 3140: 3139: 3137: 3129: 3123: 3122: 3120: 3112: 3106: 3105: 3103: 3095: 3089: 3082: 3076: 3075: 3066: 3064:10.17487/RFC3611 3051:Caceres, Ramon. 3048: 3042: 3041: 3034: 3028: 3027: 3025: 3023: 3013: 3004: 3003: 2967: 2961: 2960: 2958: 2956: 2946: 2929: 2928: 2917: 2911: 2910: 2908: 2906: 2895: 2889: 2888: 2886: 2884: 2869: 2863: 2862: 2860: 2858: 2843: 2834: 2833: 2831: 2829: 2814: 2808: 2807: 2805: 2803: 2798:on July 28, 2011 2787: 2781: 2780: 2778: 2776: 2760: 2754: 2753: 2751: 2749: 2739: 2733: 2732: 2730: 2728: 2718: 2712: 2711: 2705: 2697: 2695: 2693: 2678: 2672: 2671: 2665: 2657: 2655: 2653: 2638: 2632: 2631: 2629: 2621: 2615: 2614: 2612: 2610: 2595: 2589: 2588: 2580: 2574: 2573: 2571: 2569: 2559: 2553: 2552: 2526: 2502: 2496: 2495: 2483: 2477: 2476: 2474: 2472: 2461: 2455: 2454: 2440: 2438: 2429:. Archived from 2418: 2412: 2411: 2400: 2383: 2376: 2370: 2363: 2357: 2353: 2347: 2346: 2343: 2342: 2339: 2336: 2327: 2319: 2111:coding standard. 1892: 1881: 1839:Fumitada Itakura 1750: 1737:Fumitada Itakura 1733:data compression 1715: 1711: 1567: 1397: 1394: 1388: 1376: 1375: 1368: 1356:Operational cost 1201:secure telephone 976: 969: 965: 962: 956: 933: 925: 921:PSTN integration 741:bottleneck links 649:circuit switched 632:site-to-site VPN 21: 6968: 6967: 6963: 6962: 6961: 6959: 6958: 6957: 6923: 6922: 6921: 6916: 6876: 6874: 6866: 6808: 6745: 6667: 6631: 6588: 6537: 6529: 6470: 6463: 6369:Robert Metcalfe 6224:Tim Berners-Lee 6172: 5992:Information Age 5864: 5859: 5829: 5824: 5816: 5814: 5806: 5804: 5798: 5779:Telephone calls 5762: 5731: 5670: 5649: 5640:Satellite phone 5630:Cable telephony 5613: 5608: 5578: 5573: 5547: 5482: 5422: 5384: 5379: 5322: 5317: 5316: 5292: 5291: 5287: 5281:Wayback Machine 5270:Wayback Machine 5261: 5257: 5247: 5245: 5236: 5235: 5231: 5221: 5219: 5214: 5213: 5209: 5203:Wayback Machine 5194: 5190: 5180: 5178: 5169: 5168: 5164: 5157: 5138: 5137: 5133: 5123: 5121: 5112: 5111: 5107: 5100: 5087: 5086: 5082: 5072: 5070: 5057: 5050: 5049: 5045: 5035: 5033: 5020: 5013: 5012: 5008: 5001: 4982: 4981: 4977: 4967: 4965: 4956: 4955: 4951: 4941: 4939: 4934: 4933: 4929: 4919: 4917: 4912: 4911: 4907: 4898: 4894: 4884: 4882: 4877: 4876: 4872: 4862: 4860: 4855: 4854: 4850: 4845:Wayback Machine 4834:Wayback Machine 4824: 4820: 4810: 4808: 4803: 4802: 4798: 4788: 4786: 4782: 4777: 4776: 4772: 4762: 4760: 4756: 4752: 4751: 4747: 4737: 4735: 4718: 4717: 4713: 4699: 4698: 4694: 4684: 4682: 4672: 4671: 4664: 4654: 4652: 4643: 4642: 4638: 4614: 4609: 4608: 4604: 4597: 4593: 4581: 4574: 4564: 4562: 4558: 4527: 4522: 4521: 4517: 4483: 4478: 4477: 4464: 4454: 4452: 4450: 4436: 4435: 4431: 4421: 4419: 4414: 4413: 4409: 4399: 4397: 4388: 4387: 4383: 4373: 4371: 4366: 4365: 4361: 4351: 4349: 4344: 4343: 4339: 4333:Wayback Machine 4324: 4320: 4310: 4308: 4299: 4298: 4294: 4279: 4278: 4274: 4266: 4262: 4249: 4247: 4243: 4236: 4231: 4230: 4223: 4213: 4211: 4202: 4201: 4197: 4187: 4185: 4176: 4175: 4171: 4161: 4159: 4150: 4149: 4145: 4135: 4133: 4124: 4123: 4119: 4109: 4107: 4106:. June 26, 2017 4098: 4097: 4093: 4083: 4081: 4072: 4071: 4067: 4057: 4055: 4046: 4045: 4041: 4031: 4029: 4020: 4019: 4015: 4008:"Voice over IP" 4006: 4005: 4001: 3991: 3989: 3980: 3979: 3975: 3966: 3965: 3961: 3951: 3949: 3948:on June 2, 2012 3945: 3938: 3933: 3932: 3928: 3918: 3916: 3911: 3910: 3906: 3898: 3891: 3887: 3886: 3882: 3874: 3870: 3860: 3858: 3849: 3848: 3844: 3836: 3832: 3822: 3820: 3813: 3809: 3808: 3804: 3794: 3792: 3784: 3783: 3779: 3766: 3765: 3761: 3751: 3749: 3736: 3735: 3731: 3721: 3719: 3718:on May 17, 2006 3715: 3701: 3668: 3663: 3662: 3658: 3640: 3639: 3635: 3627: 3612: 3607: 3606: 3602: 3594: 3583: 3579: 3578: 3574: 3566: 3559: 3555: 3554: 3550: 3540: 3538: 3529: 3528: 3524: 3514: 3512: 3511:on June 4, 2009 3499: 3498: 3494: 3483:Soft-Switch.org 3477: 3476: 3472: 3462: 3460: 3451: 3450: 3446: 3436: 3434: 3430: 3419: 3415: 3414: 3407: 3397: 3395: 3382: 3381: 3377: 3367: 3365: 3352: 3351: 3347: 3340: 3325: 3324: 3320: 3310: 3308: 3303: 3302: 3298: 3288: 3286: 3281: 3280: 3276: 3266: 3264: 3259: 3258: 3254: 3244: 3242: 3237: 3236: 3232: 3222: 3220: 3215: 3214: 3210: 3193: 3186: 3184: 3179: 3178: 3174: 3166: 3162: 3161: 3157: 3148: 3147: 3143: 3135: 3131: 3130: 3126: 3118: 3114: 3113: 3109: 3101: 3097: 3096: 3092: 3083: 3079: 3050: 3049: 3045: 3036: 3035: 3031: 3021: 3019: 3015: 3014: 3007: 2969: 2968: 2964: 2954: 2952: 2948: 2947: 2932: 2919: 2918: 2914: 2904: 2902: 2897: 2896: 2892: 2882: 2880: 2871: 2870: 2866: 2856: 2854: 2845: 2844: 2837: 2827: 2825: 2816: 2815: 2811: 2801: 2799: 2789: 2788: 2784: 2774: 2772: 2762: 2761: 2757: 2747: 2745: 2741: 2740: 2736: 2726: 2724: 2720: 2719: 2715: 2698: 2691: 2689: 2680: 2679: 2675: 2658: 2651: 2649: 2646:www.eetimes.com 2640: 2639: 2635: 2627: 2623: 2622: 2618: 2608: 2606: 2597: 2596: 2592: 2582: 2581: 2577: 2567: 2565: 2561: 2560: 2556: 2504: 2503: 2499: 2485: 2484: 2480: 2470: 2468: 2463: 2462: 2458: 2436: 2434: 2420: 2419: 2415: 2402: 2401: 2397: 2392: 2387: 2386: 2377: 2373: 2364: 2360: 2351: 2333: 2329: 2322: 2320: 2316: 2311: 2306: 2212: 2089:(PBX) software. 1890: 1879: 1856:application by 1830: 1748: 1713: 1709: 1662: 1635:interconnection 1606: 1586: 1565: 1537: 1497: 1485: 1473: 1468: 1449: 1429: 1398: 1392: 1389: 1386: 1377: 1373: 1366: 1358: 1342: 1330: 1265:(SRTP) and the 1193: 1164: 1128: 1065: 1063:Emergency calls 1035: 1016:email addresses 977: 966: 960: 957: 946: 934: 923: 903: 835:data link layer 831: 792: 677:queueing delays 640: 598: 572: 552: 509: 487: 429: 427:Consumer market 424: 311:synchronization 241: 219:In addition to 134:stereo codecs. 100: 84:voice messaging 39:), also called 28: 23: 22: 15: 12: 11: 5: 6966: 6964: 6956: 6955: 6950: 6945: 6943:Videotelephony 6940: 6935: 6925: 6924: 6918: 6917: 6915: 6914: 6904: 6894: 6884: 6871: 6868: 6867: 6865: 6864: 6857: 6852: 6847: 6842: 6837: 6836: 6835: 6830: 6822: 6816: 6814: 6810: 6809: 6807: 6806: 6801: 6796: 6791: 6786: 6781: 6776: 6771: 6766: 6761: 6755: 6753: 6747: 6746: 6744: 6743: 6738: 6733: 6728: 6723: 6718: 6713: 6708: 6703: 6698: 6693: 6688: 6683: 6677: 6675: 6669: 6668: 6666: 6665: 6660: 6655: 6650: 6645: 6639: 6637: 6633: 6632: 6630: 6629: 6624: 6619: 6614: 6609: 6604: 6602:Space-division 6598: 6596: 6590: 6589: 6587: 6586: 6581: 6580: 6579: 6574: 6564: 6563: 6562: 6552: 6547: 6541: 6539: 6531: 6530: 6528: 6527: 6526: 6525: 6515: 6514: 6513: 6503: 6498: 6493: 6492: 6491: 6481: 6475: 6473: 6465: 6464: 6462: 6461: 6456: 6451: 6446: 6441: 6439:Camille Tissot 6436: 6431: 6426: 6421: 6416: 6414:Claude Shannon 6411: 6406: 6404:Tivadar Puskás 6401: 6396: 6391: 6386: 6381: 6376: 6374:Antonio Meucci 6371: 6366: 6361: 6356: 6351: 6346: 6344:Charles K. Kao 6341: 6336: 6331: 6326: 6321: 6319:Harold Hopkins 6316: 6311: 6306: 6301: 6296: 6291: 6286: 6281: 6276: 6271: 6266: 6261: 6256: 6251: 6246: 6241: 6236: 6231: 6226: 6221: 6219:Emile Berliner 6216: 6211: 6206: 6201: 6196: 6191: 6186: 6180: 6178: 6174: 6173: 6171: 6170: 6165: 6160: 6158:Videotelephony 6155: 6150: 6149: 6148: 6143: 6133: 6126: 6121: 6115: 6110: 6105: 6100: 6095: 6094: 6093: 6088: 6083: 6073: 6072: 6071: 6061: 6056: 6054:Radiotelephone 6051: 6046: 6041: 6036: 6031: 6026: 6021: 6020: 6019: 6009: 6004: 5999: 5994: 5989: 5984: 5979: 5974: 5969: 5964: 5959: 5958: 5957: 5952: 5947: 5942: 5940:Internet video 5932: 5931: 5930: 5925: 5920: 5915: 5905: 5900: 5895: 5890: 5885: 5880: 5874: 5872: 5866: 5865: 5860: 5858: 5857: 5850: 5843: 5835: 5826: 5825: 5803: 5800: 5799: 5797: 5796: 5791: 5786: 5781: 5776: 5770: 5768: 5764: 5763: 5761: 5760: 5755: 5750: 5748:Misdialed call 5745: 5739: 5737: 5733: 5732: 5730: 5729: 5724: 5719: 5714: 5709: 5704: 5699: 5694: 5689: 5684: 5678: 5676: 5672: 5671: 5669: 5668: 5663: 5657: 5655: 5651: 5650: 5648: 5647: 5642: 5637: 5632: 5627: 5621: 5619: 5615: 5614: 5609: 5607: 5606: 5599: 5592: 5584: 5575: 5574: 5572: 5571: 5566: 5561: 5555: 5553: 5549: 5548: 5546: 5545: 5540: 5535: 5534: 5533: 5523: 5518: 5513: 5508: 5503: 5498: 5492: 5490: 5484: 5483: 5481: 5480: 5475: 5470: 5469: 5468: 5463: 5456:Internet forum 5453: 5448: 5443: 5438: 5432: 5430: 5424: 5423: 5421: 5420: 5415: 5410: 5405: 5400: 5395: 5389: 5386: 5385: 5380: 5378: 5377: 5370: 5363: 5355: 5349: 5348: 5337: 5321: 5320:External links 5318: 5315: 5314: 5285: 5255: 5229: 5207: 5188: 5162: 5155: 5149:. p. 69. 5131: 5105: 5098: 5080: 5063:Fraunhofer IIS 5043: 5026:Fraunhofer IIS 5006: 4999: 4993:. p. 55. 4975: 4949: 4927: 4905: 4892: 4870: 4848: 4818: 4796: 4778:Keating, Tom. 4770: 4754:"MTALK-Readme" 4745: 4711: 4692: 4662: 4651:on May 7, 2006 4636: 4625:(5): 637–648. 4602: 4591: 4572: 4515: 4494:(4): 203–303. 4462: 4448: 4429: 4407: 4381: 4359: 4337: 4318: 4292: 4272: 4260: 4221: 4195: 4169: 4143: 4117: 4091: 4065: 4039: 4013: 3999: 3973: 3959: 3926: 3904: 3880: 3868: 3842: 3830: 3802: 3777: 3759: 3729: 3699: 3682:10.1.1.219.633 3656: 3647:SANS Institute 3633: 3600: 3572: 3548: 3522: 3492: 3470: 3444: 3405: 3375: 3345: 3338: 3318: 3296: 3274: 3252: 3230: 3208: 3172: 3155: 3141: 3124: 3107: 3090: 3077: 3043: 3029: 3005: 2962: 2930: 2912: 2890: 2864: 2835: 2809: 2782: 2755: 2734: 2713: 2673: 2633: 2616: 2590: 2575: 2554: 2517:(1): 184–199. 2497: 2478: 2456: 2413: 2394: 2393: 2391: 2388: 2385: 2384: 2371: 2358: 2328:or as a word, 2313: 2312: 2310: 2307: 2305: 2304: 2302:VoIP recording 2299: 2294: 2289: 2287:Voice over LTE 2284: 2279: 2274: 2269: 2264: 2259: 2254: 2249: 2244: 2239: 2234: 2229: 2224: 2219: 2213: 2211: 2208: 2207: 2206: 2199: 2198: 2197: 2191: 2181: 2170: 2159: 2156: 2149: 2142: 2139: 2132: 2121: 2120: 2119: 2112: 2109:wideband audio 2090: 2069: 2059: 2048: 2047: 2046: 2040: 2037: 2024: 2023: 2022: 2008: 2005:Internet Phone 1995: 1989: 1982: 1974: 1967: 1964: 1958:Voice over ATM 1954: 1951:Bishnu S. Atal 1939: 1928: 1921: 1906: 1887: 1886:encoded voice. 1868: 1861: 1850: 1829: 1826: 1824:to telephony. 1822:cloud services 1773:Bishnu S. Atal 1702:digital speech 1666:packet network 1661: 1658: 1626:Interconnected 1605: 1602: 1585: 1582: 1581: 1580: 1577: 1569: 1562: 1559: 1556: 1536: 1533: 1496: 1493: 1484: 1481: 1472: 1469: 1467: 1461: 1453:European Union 1448: 1447:European Union 1445: 1428: 1425: 1400: 1399: 1380: 1378: 1371: 1365: 1362: 1357: 1354: 1341: 1338: 1329: 1326: 1283:point-to-point 1192: 1189: 1163: 1160: 1156:data integrity 1127: 1124: 1064: 1061: 1034: 1031: 979: 978: 937: 935: 928: 922: 919: 902: 899: 898: 897: 890:coaxial cables 871: 861: 839:physical layer 830: 827: 791: 788: 717:playout buffer 652:problems with 639: 636: 597: 594: 571: 568: 551: 548: 508: 505: 486: 483: 482: 481: 474: 463: 428: 425: 423: 420: 419: 418: 415:Skype protocol 412: 406: 400: 390: 380: 374: 368: 362: 356: 350: 344: 338: 336:videotelephony 321: 320: 314: 304: 298: 292: 280: 270: 249:open standards 240: 237: 214:federated VoIP 99: 96: 51:sessions over 26: 24: 14: 13: 10: 9: 6: 4: 3: 2: 6965: 6954: 6951: 6949: 6946: 6944: 6941: 6939: 6936: 6934: 6933:Voice over IP 6931: 6930: 6928: 6913: 6905: 6903: 6895: 6893: 6885: 6883: 6873: 6872: 6869: 6862: 6858: 6856: 6853: 6851: 6848: 6846: 6843: 6841: 6838: 6834: 6831: 6829: 6826: 6825: 6823: 6821: 6818: 6817: 6815: 6811: 6805: 6802: 6800: 6797: 6795: 6792: 6790: 6787: 6785: 6782: 6780: 6777: 6775: 6772: 6770: 6767: 6765: 6762: 6760: 6757: 6756: 6754: 6752: 6748: 6742: 6739: 6737: 6734: 6732: 6729: 6727: 6724: 6722: 6719: 6717: 6714: 6712: 6709: 6707: 6704: 6702: 6699: 6697: 6694: 6692: 6689: 6687: 6684: 6682: 6679: 6678: 6676: 6674: 6670: 6664: 6661: 6659: 6656: 6654: 6651: 6649: 6646: 6644: 6641: 6640: 6638: 6634: 6628: 6627:Code-division 6625: 6623: 6620: 6618: 6615: 6613: 6612:Time-division 6610: 6608: 6605: 6603: 6600: 6599: 6597: 6595: 6591: 6585: 6582: 6578: 6575: 6573: 6570: 6569: 6568: 6565: 6561: 6558: 6557: 6556: 6553: 6551: 6548: 6546: 6543: 6542: 6540: 6538:and switching 6536: 6532: 6524: 6521: 6520: 6519: 6516: 6512: 6509: 6508: 6507: 6504: 6502: 6499: 6497: 6494: 6490: 6489:optical fiber 6487: 6486: 6485: 6482: 6480: 6479:Coaxial cable 6477: 6476: 6474: 6472: 6466: 6460: 6457: 6455: 6452: 6450: 6447: 6445: 6442: 6440: 6437: 6435: 6432: 6430: 6427: 6425: 6422: 6420: 6417: 6415: 6412: 6410: 6407: 6405: 6402: 6400: 6397: 6395: 6394:Radia Perlman 6392: 6390: 6387: 6385: 6382: 6380: 6377: 6375: 6372: 6370: 6367: 6365: 6362: 6360: 6357: 6355: 6352: 6350: 6347: 6345: 6342: 6340: 6337: 6335: 6332: 6330: 6327: 6325: 6322: 6320: 6317: 6315: 6312: 6310: 6307: 6305: 6302: 6300: 6297: 6295: 6292: 6290: 6287: 6285: 6284:Lee de Forest 6282: 6280: 6279:Thomas Edison 6277: 6275: 6272: 6270: 6269:Donald Davies 6267: 6265: 6262: 6260: 6257: 6255: 6254:Claude Chappe 6252: 6250: 6247: 6245: 6242: 6240: 6237: 6235: 6232: 6230: 6227: 6225: 6222: 6220: 6217: 6215: 6212: 6210: 6207: 6205: 6202: 6200: 6197: 6195: 6192: 6190: 6187: 6185: 6182: 6181: 6179: 6175: 6169: 6166: 6164: 6161: 6159: 6156: 6154: 6151: 6147: 6144: 6142: 6139: 6138: 6137: 6134: 6132: 6131: 6127: 6125: 6122: 6119: 6116: 6114: 6111: 6109: 6106: 6104: 6101: 6099: 6098:Smoke signals 6096: 6092: 6089: 6087: 6084: 6082: 6079: 6078: 6077: 6076:Semiconductor 6074: 6070: 6067: 6066: 6065: 6062: 6060: 6057: 6055: 6052: 6050: 6047: 6045: 6042: 6040: 6037: 6035: 6032: 6030: 6027: 6025: 6022: 6018: 6015: 6014: 6013: 6010: 6008: 6005: 6003: 6000: 5998: 5995: 5993: 5990: 5988: 5985: 5983: 5980: 5978: 5975: 5973: 5970: 5968: 5965: 5963: 5960: 5956: 5953: 5951: 5948: 5946: 5943: 5941: 5938: 5937: 5936: 5935:Digital media 5933: 5929: 5926: 5924: 5921: 5919: 5916: 5914: 5911: 5910: 5909: 5906: 5904: 5901: 5899: 5896: 5894: 5891: 5889: 5886: 5884: 5881: 5879: 5876: 5875: 5873: 5871: 5867: 5863: 5856: 5851: 5849: 5844: 5842: 5837: 5836: 5833: 5823: 5813: 5801: 5795: 5792: 5790: 5787: 5785: 5782: 5780: 5777: 5775: 5772: 5771: 5769: 5765: 5759: 5756: 5754: 5753:Nuisance call 5751: 5749: 5746: 5744: 5741: 5740: 5738: 5734: 5728: 5725: 5723: 5720: 5718: 5715: 5713: 5710: 5708: 5705: 5703: 5700: 5698: 5695: 5693: 5692:Fibre-optical 5690: 5688: 5685: 5683: 5680: 5679: 5677: 5673: 5667: 5664: 5662: 5659: 5658: 5656: 5652: 5646: 5643: 5641: 5638: 5636: 5633: 5631: 5628: 5626: 5623: 5622: 5620: 5616: 5612: 5605: 5600: 5598: 5593: 5591: 5586: 5585: 5582: 5570: 5567: 5565: 5564:Microblogging 5562: 5560: 5557: 5556: 5554: 5550: 5544: 5541: 5539: 5536: 5532: 5529: 5528: 5527: 5526:Voice over IP 5524: 5522: 5519: 5517: 5514: 5512: 5511:LAN messenger 5509: 5507: 5504: 5502: 5499: 5497: 5494: 5493: 5491: 5489: 5485: 5479: 5476: 5474: 5471: 5467: 5464: 5462: 5459: 5458: 5457: 5454: 5452: 5449: 5447: 5444: 5442: 5439: 5437: 5434: 5433: 5431: 5429: 5425: 5419: 5416: 5414: 5411: 5409: 5406: 5404: 5401: 5399: 5396: 5394: 5391: 5390: 5387: 5383: 5376: 5371: 5369: 5364: 5362: 5357: 5356: 5353: 5346: 5342: 5338: 5336:at Wiktionary 5335: 5334: 5328: 5324: 5323: 5319: 5309: 5304: 5300: 5296: 5289: 5286: 5282: 5278: 5275: 5271: 5267: 5264: 5259: 5256: 5244: 5240: 5233: 5230: 5217: 5211: 5208: 5204: 5200: 5197: 5192: 5189: 5177: 5173: 5166: 5163: 5158: 5156:9780470377864 5152: 5148: 5144: 5143: 5135: 5132: 5120: 5116: 5109: 5106: 5101: 5095: 5091: 5084: 5081: 5069: 5065: 5064: 5056: 5055: 5047: 5044: 5032: 5028: 5027: 5019: 5018: 5010: 5007: 5002: 5000:9780470023631 4996: 4992: 4988: 4987: 4979: 4976: 4963: 4959: 4953: 4950: 4937: 4931: 4928: 4915: 4909: 4906: 4903:, March 1996. 4902: 4896: 4893: 4880: 4874: 4871: 4858: 4852: 4849: 4846: 4842: 4839: 4836:June 2, 1997 4835: 4831: 4828: 4822: 4819: 4806: 4800: 4797: 4781: 4774: 4771: 4759:. Sunsite.edu 4755: 4749: 4746: 4734: 4730: 4726: 4725:Network World 4722: 4715: 4712: 4707: 4703: 4696: 4693: 4685:September 14, 4680: 4676: 4669: 4667: 4663: 4650: 4646: 4640: 4637: 4632: 4628: 4624: 4620: 4613: 4606: 4603: 4600: 4595: 4592: 4588: 4587: 4579: 4577: 4573: 4557: 4553: 4549: 4545: 4541: 4537: 4533: 4526: 4519: 4516: 4511: 4507: 4502: 4497: 4493: 4489: 4482: 4475: 4473: 4471: 4469: 4467: 4463: 4451: 4449:9781118909706 4445: 4441: 4440: 4433: 4430: 4417: 4416:"Danny Cohen" 4411: 4408: 4396: 4392: 4385: 4382: 4374:September 21, 4369: 4363: 4360: 4347: 4341: 4338: 4334: 4330: 4327: 4322: 4319: 4311:September 21, 4307: 4303: 4296: 4293: 4288: 4284: 4283: 4276: 4273: 4270: 4264: 4261: 4257: 4250:September 19, 4242: 4235: 4228: 4226: 4222: 4209: 4205: 4199: 4196: 4184: 4180: 4173: 4170: 4158: 4154: 4147: 4144: 4132: 4128: 4121: 4118: 4105: 4101: 4095: 4092: 4079: 4075: 4069: 4066: 4053: 4049: 4043: 4040: 4032:September 20, 4028: 4024: 4017: 4014: 4009: 4003: 4000: 3987: 3983: 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2240: 2238: 2235: 2233: 2230: 2228: 2225: 2223: 2220: 2218: 2217:Audio over IP 2215: 2214: 2209: 2204: 2200: 2195: 2192: 2189: 2185: 2184: 2182: 2179: 2175: 2171: 2168: 2164: 2160: 2157: 2154: 2150: 2147: 2143: 2140: 2137: 2133: 2130: 2126: 2122: 2117: 2113: 2110: 2107: 2103: 2099: 2095: 2091: 2088: 2085: 2081: 2077: 2073: 2070: 2067: 2063: 2062: 2060: 2057: 2053: 2049: 2044: 2041: 2038: 2035: 2031: 2028: 2027: 2025: 2020: 2016: 2012: 2009: 2006: 2002: 1999: 1998: 1996: 1994: 1990: 1987: 1983: 1979: 1975: 1972: 1968: 1965: 1963: 1959: 1955: 1952: 1948: 1944: 1940: 1937: 1933: 1929: 1926: 1922: 1919: 1915: 1911: 1907: 1904: 1900: 1896: 1888: 1885: 1877: 1873: 1869: 1866: 1862: 1859: 1855: 1851: 1848: 1844: 1840: 1836: 1832: 1831: 1827: 1825: 1823: 1819: 1815: 1811: 1807: 1803: 1799: 1795: 1794:Lior Haramaty 1791: 1786: 1780: 1778: 1774: 1770: 1766: 1762: 1758: 1754: 1746: 1742: 1738: 1734: 1731: 1730:speech coding 1727: 1723: 1719: 1707: 1703: 1699: 1694: 1692: 1688: 1684: 1680: 1676: 1671: 1667: 1659: 1657: 1655: 1651: 1646: 1644: 1640: 1636: 1631: 1627: 1624:Operators of 1622: 1620: 1616: 1612: 1604:United States 1603: 1601: 1599: 1595: 1591: 1583: 1578: 1575: 1570: 1563: 1560: 1557: 1554: 1553: 1552: 1549: 1546: 1545:VoIP gateways 1542: 1534: 1532: 1530: 1526: 1522: 1518: 1513: 1511: 1506: 1502: 1494: 1492: 1490: 1482: 1480: 1478: 1470: 1466: 1462: 1460: 1456: 1454: 1446: 1444: 1442: 1438: 1434: 1426: 1424: 1422: 1418: 1414: 1410: 1405: 1396: 1384: 1379: 1370: 1369: 1363: 1361: 1355: 1353: 1351: 1347: 1339: 1337: 1335: 1327: 1325: 1323: 1319: 1314: 1312: 1308: 1304: 1300: 1294: 1292: 1288: 1284: 1280: 1276: 1272: 1269:protocol for 1268: 1264: 1259: 1257: 1253: 1249: 1245: 1241: 1237: 1232: 1229: 1225: 1221: 1216: 1214: 1210: 1206: 1202: 1198: 1190: 1188: 1185: 1181: 1177: 1172: 1169: 1161: 1159: 1157: 1151: 1149: 1144: 1139: 1137: 1133: 1125: 1123: 1121: 1117: 1113: 1109: 1104: 1102: 1098: 1093: 1090: 1086: 1081: 1079: 1073: 1070: 1062: 1060: 1056: 1054: 1049: 1047: 1043: 1039: 1032: 1030: 1028: 1023: 1021: 1017: 1013: 1009: 1005: 1001: 997: 993: 989: 986: 975: 972: 964: 961:November 2019 954: 950: 944: 943: 938:This section 936: 932: 927: 926: 920: 918: 916: 912: 908: 900: 895: 891: 887: 883: 879: 876: 872: 869: 865: 862: 859: 855: 851: 848: 847: 846: 844: 840: 836: 828: 826: 822: 820: 816: 812: 808: 803: 801: 797: 789: 787: 785: 780: 776: 771: 769: 765: 761: 757: 753: 748: 746: 742: 738: 734: 728: 726: 722: 718: 714: 713:queuing delay 710: 705: 703: 699: 693: 690: 686: 682: 678: 673: 671: 667: 661: 659: 655: 650: 646: 637: 635: 633: 628: 626: 621: 617: 615: 606: 602: 595: 593: 589: 587: 582: 580: 576: 569: 567: 565: 561: 556: 549: 547: 545: 541: 538: 533: 531: 527: 521: 519: 515: 507:Corporate use 506: 504: 502: 498: 496: 492: 484: 478: 475: 472: 468: 464: 461: 457: 453: 452: 451: 448: 446: 442: 433: 426: 421: 416: 413: 410: 407: 404: 401: 398: 394: 391: 388: 384: 381: 378: 375: 372: 369: 366: 363: 360: 357: 354: 351: 348: 345: 342: 339: 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Retrieved 5243:AppleInsider 5232: 5220:. Retrieved 5210: 5191: 5179:. Retrieved 5175: 5165: 5141: 5134: 5122:. Retrieved 5118: 5108: 5089: 5083: 5071:. Retrieved 5061: 5053: 5046: 5034:. Retrieved 5024: 5016: 5009: 4985: 4978: 4966:. Retrieved 4962:the original 4952: 4940:. Retrieved 4930: 4918:. Retrieved 4908: 4900: 4895: 4883:. Retrieved 4873: 4861:. Retrieved 4851: 4821: 4809:. Retrieved 4799: 4787:. Retrieved 4773: 4761:. Retrieved 4748: 4738:February 10, 4736:. Retrieved 4724: 4714: 4705: 4695: 4683:. Retrieved 4678: 4653:. Retrieved 4649:the original 4639: 4622: 4618: 4605: 4594: 4583: 4563:. Retrieved 4556:the original 4535: 4531: 4518: 4491: 4487: 4453:. Retrieved 4438: 4432: 4420:. Retrieved 4410: 4398:. Retrieved 4394: 4384: 4372:. Retrieved 4362: 4350:. Retrieved 4340: 4321: 4309:. Retrieved 4305: 4295: 4287:the original 4281: 4275: 4263: 4255: 4248:. Retrieved 4241:the original 4212:. Retrieved 4207: 4198: 4186:. Retrieved 4183:The National 4182: 4172: 4160:. 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