116:
be a pair of RF connectors for every service group, although it is possible to configure a network with different numbers of connectors that service a set of service groups, based on the number of downstream and upstream channels the cable modems in every service group use. Every connector has a finite number of channels it can carry, such as 16 channels per downstream connector, and 4 channels per upstream connector, depending on the CMTS. For example, if the cable modems on every service group use 24 channels for downstream, and 2 channels for upstream, then 3 downstream connectors can service the cable modems on two service groups, and be serviced by 1 upstream connector. A service group may serve up to 500 households. A service group has channels, whose bandwidth is shared among all members of the service group. The channels are later regrouped at the cable headend or distribution hub and serviced by CMTSs and other equipment such as Edge QAMs.
235:(Converged Cable Access Platform) combines CMTS and Edge QAM functionality in a single device so that it can provide both data (internet) with CMTS functionality, and video (TV channels) with Edge QAM functionality. Edge QAM (Quadrature Amplitude Modulator/Modulation) converts video sent via IP (internet protocol) or otherwise, into a QAM signal for delivery over a cable network. Edge QAMs are normally standalone devices placed at the "edge" of a network. They can also be connected to a CMTS core, to make up an M-CMTS system which is more scalable. A CMTS core is normally a conventional or I-CMTS that supports operation as a CMTS core in an M-CMTS system.
20:
120:
receiver modules that turn the RF signals into light pulses for delivery over fiber optics through an HFC network. Examples of optics platforms are the Arris CH3000 and Cisco Prisma II. At the other end of the network, an optical node converts the light pulses into RF signals again and sends them through a coaxial cable "trunk". The trunk has one or more amplifiers along its length, and on the trunk there are distribution "taps" to which customers' modems are connected via coaxial cable.
258:
Downstream
External PHY Interface (DEPI). The DEPI protocol controls the delivery of DOCSIS frames from the M-CMTS Core to the EQAM devices Some of the challenges that entail an M-CMTS platform are increased complexity in RF combining and an increase in the number of failure points. One of the benefits of an M-CMTS architecture is that it is extremely scalable to larger numbers of downstream channels.
87:. Different CMTSs are capable of serving different cable modem population sizes—ranging from 4,000 cable modems to 150,000 or more, depending in part on traffic, although it is recommended for an I-CMTS to service, for example, 30,000 subscribers (cable modems). A given headend may have between 1–12 CMTSs to service the cable modem population served by that headend or
115:
A CMTS has separate RF interfaces and connectors for downlink and uplink signals. The RF/coax interfaces carry RF signals to and from coaxial "trunks" connected to subscribers' cable modems, using one pair of connectors per trunk, one for downlink and the other for uplink. In other words, there can
610:
is 16 streams per slot, every slot has 16 connectors. The router has 14 slots but 2 are reserved, a service group has separate downlink and uplink cables at the CMTS according to diagram in Data-Over-Cable
Service Interface Specifications DOCSIS® 3.1 and the Arris E6000 manual where upstream and
119:
The RF signals from a CMTS, are connected via coaxial cable to headend RF management modules for RF splitting and combining, with other equipment such as other CMTSs so that several CMTS can service one service group, and then to an "optics platform" or headend platform, which has transmitter and
257:
MAC Component which is referred to as the M-CMTS Core. There are also several new protocols and components introduced with this type of architecture. One is the DOCSIS Timing
Interface, which provides a reference frequency between the EQAM and M-CMTS Core via a DTI Server. The second is the
243:
A CMTS can be broken down into several different architectures, Integrated CMTS (I-CMTS), Modular (M-CMTS), Virtual CMTS (vCMTS) and remote CMTS. An I-CMTS incorporates into a single unit all components necessary for its operation. There are both pros and cons to each type of architecture.
266:
Virtual CCAPs (vCCAPs) or virtual CMTSs (vCMTSs) are implemented on commercial off the shelf x86-based servers with specialized software, and can be used to increase service capacity without purchasing new CMTS/CCAP chassis, or add features to the CMTS/CCAP more quickly.
227:
cannot communicate directly with other modems on the line. In general, cable modem traffic is routed to other cable modems or to the
Internet through a series of CMTSs and traditional routers. However, a route could conceivably pass through a single CMTS.
636:
mentions "coax feeder cable" instead of trunk but mentions trunk or distribution amplifiers on the feeder which originates from an optical node or just node according to
Optical Node Series (NC) NC4000H4 1.2 GHz Fiber Deep Node
252:
In a M-CMTS solution the architecture of an I-CMTS is broken up into two components. The first part is the
Physical Downstream component (PHY) which is known as the Edge QAM (EQAM). The second part is the IP networking and
139:). The traffic winds its way through the HFC to end up at the cable modem in the subscriber's home. Traffic from a subscriber's home system goes through the cable modem and out to the Internet in the opposite direction.
192:
requests to the relevant servers. This DHCP server returns, for the most part, what looks like a typical response including an assigned IP address for the computer, gateway/router addresses to use, DNS servers, etc.
696:
Cisco DOCSIS 3.0 Downstream
Solution Design and Implementation Guide Chapter 3: Solution Overview for I-CMTS www.cisco.com/c/en/us/td/docs/cable/cmts/wideband/solution/guide/release_2-0/ds_solu/overvw_icmts.html
705:
Cisco DOCSIS 3.0 Downstream
Solution Design and Implementation Guide Chapter 2: Solution Overview for M-CMTS www.cisco.com/c/en/us/td/docs/cable/cmts/wideband/solution/guide/release_2-0/ds_solu/1overvw.html
611:
downstream ports use different connectors
Physical Layer Specification and also to make use of 192 connectors in 12 slots with 16 connectors per slot but only 96 downlink and 96 uplink service groups
275:
Remote CMTS/Remote CCAP moves all CMTS/CCAP functionality to the outside plant, in stark contrast to conventional CMTSs or CCAPs which are installed at a service provider location.
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is a CCAP (CMTS) that can handle 96 upstream and 96 downstream service groups for a total of 192 streams, divided by 12 available slots in the router's image and in
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750:
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can be routed (or bridged) through the
Ethernet interface, through the CMTS and then onto the RF interfaces that are connected to the cable company's
157:
Upstream data (data from cable modems to the headend or Internet) is carried in Ethernet frames encapsulated inside DOCSIS frames modulated with
146:
traffic. Traffic destined for the cable modem from the Internet, known as downstream traffic, is carried in IP packets encapsulated according to
578:
527:
Data-Over-Cable Service Interface Specifications DOCSIS® 3.0 MAC and Upper Layer Protocols Interface Specification CM-SP-MULPIv3.0-C01-171207
200:
is sometimes performed to prioritize application traffic, perhaps based upon subscribed plan or download usage and also to provide guaranteed
150:
standard. These packets are carried on data streams that are typically modulated onto a TV channel using either 64-QAM or 256-QAM versions of
79:
In order to provide high speed data services, a cable company will connect its headend to the Internet via very high capacity data links to a
734:
212:
service. However, the function of traffic shaping is more likely done by a Cable Modem or policy traffic switch. A CMTS may also act as a
189:
864:
685:
624:
has 16 ports for downstream signals, occupies 1 slot in a 14-slot e6000 chassis where 2 slots are reserved for router system modules
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177:(also known as the "T" channels), a much lower part of the frequency spectrum than the downstream signal, usually 5–42 MHz in
803:
428:
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Data-Over-Cable Service Interface Specifications DOCSIS® 4.0 Physical Layer Specification CM-SP-PHYv4.0-I06-221019. Cablelabs.
124:
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mentions upstream modules with 96 channels divided by 24 ports, and downstream modules with 128 channels divided by 8 ports
603:
162:
668:
102:
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Data-Over-Cable Service Interface Specifications DOCSIS® 3.1 Physical Layer Specification CM-SP-PHYv3.1-I19-211110
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Data-Over-Cable Service Interface Specifications DOCSIS® 3.0 Physical Layer Specification CM-SP-PHYv3.0-C01-171207
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48:
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591:
579:
https://www.commscope.com/globalassets/digizuite/1618-arris-centralized-vs-distributed-access-networks-wp.pdf
123:
In fact, most CMTSs have both Ethernet interfaces (or other more traditional high-speed data interfaces like
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The CMTS may also implement some basic filtering to protect against unauthorized users and various attacks.
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https://www.nctatechnicalpapers.com/Paper/2015/2015-evolution-of-cmts-ccap-architectures/download
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frequency sharing mechanisms. This is usually done at the "subband" or "return" portion of the
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interfaces on the other side. The Ethernet side is known as the Network Side Interface or NSI.
730:
143:
633:
622:
https://www.normann-engineering.com/products/product_pdf/ccap_cmts/arris/e6000-cer-dcam2.pdf
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https://fccid.io/ANATEL/02605-15-07236/Manual-E6000/166C8E9C-8C13-4F42-B929-31E3DDBB82CA/PDF
552:
https://fccid.io/ANATEL/01759-14-07236/Manual-E6000/50DAF2B5-F106-42DF-A563-6008357AC079/PDF
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https://fccid.io/ANATEL/01759-14-07236/Manual-E6000/50DAF2B5-F106-42DF-A563-6008357AC079/PDF
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A Side-By Side Comparison of Centralized vs. Distributed Access Architectures. Commscope
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83:. On the subscriber side of the headend, the CMTS enables communication with subscribers'
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https://www.commscope.com/globalassets/digizuite/61837-e6000-cer-rel-6-0-data-sheet.pdf
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894:
354:
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63:, to cable subscribers. A CMTS provides many of the same functions provided by the
406:
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224:
205:
84:
56:
751:"Data-Over-Cable Service Interface Specifications Modular Headend Architecture"
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785:
592:
https://courses.cs.duke.edu/spring18/compsci356/slides/cable-hfc-intro.pdf
127:) as well as RF interfaces. In this way, traffic that is coming from the
339:
128:
99:
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E6000® Converged Edge Router Downstream Cable Access Module 2 (DCAM-2)
422:
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HFC Cable Architecture Wade Holmes one optical node per service group
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254:
178:
147:
639:
https://www.commscope.com/globalassets/digizuite/61985-nc4000h4.pdf
64:
18:
818:"Lessons from Operating Tens of Thousands of Remote PHY Devices"
209:
170:
158:
840:"Impact of CCAP to CM Distance in a Remote PHY Architecture"
398:(Exited CMTS business, remaining business later acquired by
329:
184:
A typical CMTS allows a subscriber's computer to obtain an
865:"DOCSIS Remote PHY Modular Headend Architecture (MHA v2)"
634:
https://archive.nanog.org/sites/default/files/08-Noll.pdf
804:"Harmonic's 'CableOS' now connected to 18.4M modems"
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506:
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16:Equipment used to provide high speed data services
523:
521:
726:Next Generation IPTV Services and Technologies
8:
94:One way to think of a CMTS is to imagine a
581:CMTS/CCAP handles service groups directly
161:, 16-QAM, 32-QAM, 64-QAM or 128-QAM using
51:or hubsite, which is used to provide data
729:. John Wiley & Sons. 2 January 2008.
602:E6000® Converged Edge Router Release 6.0
482:
378:Broadband Access Systems (Acquired by
7:
204:(QoS) for the cable operator's own
14:
454:Daphne sa (Acquired by Damery sa)
419:RiverDelta (Acquired by Motorola)
429:Pacific Broadband Communications
181:or 5–65 MHz in EuroDOCSIS.
414:CMTS business acquired by ARRIS
152:quadrature amplitude modulation
105:(connections) on one side and
29:cable modem termination system
23:Cable modem termination system
1:
451:Motorola (Acquired by ARRIS)
388:(CMTS business acquired by
142:CMTSs typically carry only
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330:Gainspeed (Nokia company)
335:WISI Communications GmbH
81:network service provider
673:www.lightwaveonline.com
550:The Arris E6000 manual
538:"Specifications Search"
441:(Exited CMTS business)
425:(Acquired by Motorola)
386:ADC Telecommunications
380:ADC Telecommunications
24:
444:LanCity (Acquired by
305:Coaxial Networks Inc.
300:Catapult Technologies
248:Modular CMTS (M-CMTS)
47:in a cable company's
22:
786:"CMTS Architectures"
675:. 13 September 2013.
512:Arris E6000 manual
405:Cadant (Acquired by
460:(Acquired by Cisco)
350:Huawei Technologies
458:Scientific Atlanta
371:3COM (Acquired by
320:Chongqing Jinghong
202:Quality of service
25:
758:www.cablelabs.com
736:978-0-470-16372-6
175:cable TV spectrum
133:hybrid fiber coax
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433:Juniper Networks
396:BigBand Networks
390:BigBand Networks
39:) is a piece of
37:CMTS Edge Router
35:, also called a
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57:cable Internet
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790:volpefirm.com
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767:on 2015-02-27
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872:. Retrieved
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762:the original
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85:cable modems
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43:, typically
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669:"StackPath"
446:BayNetworks
295:C9 Networks
290:ARRIS Group
271:Remote CMTS
225:cable modem
206:PacketCable
75:Connections
895:Categories
771:2015-02-27
477:References
366:Historical
186:IP address
179:DOCSIS 2.0
103:interfaces
55:, such as
565:"Exv99w1"
491:"exv99w1"
325:Damery sa
41:equipment
465:See also
340:Kathrein
129:Internet
100:Ethernet
71:system.
53:services
874:2 March
848:2 March
824:2 March
495:sec.gov
423:Terayon
412:Com21 (
360:Teleste
284:Current
208:-based
89:HFC hub
49:headend
45:located
870:. SCTE
820:. SCTE
733:
471:DOCSIS
255:DOCSIS
218:router
214:bridge
148:DOCSIS
96:router
868:(PDF)
843:(PDF)
765:(PDF)
754:(PDF)
407:ARRIS
400:ARRIS
169:or S-
167:ATDMA
125:SONET
98:with
67:in a
65:DSLAM
876:2024
850:2024
826:2024
731:ISBN
233:CCAP
210:VOIP
190:DHCP
171:CDMA
163:TDMA
159:QPSK
33:CMTS
216:or
137:HFC
69:DSL
59:or
897::
788:.
756:.
671:.
520:^
503:^
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373:HP
231:A
220:.
165:,
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144:IP
110:RF
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27:A
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