ETSI TR 101 546 V1.1.1 (2011-10)

Technical Report
Access, Terminals, Transmission and Multiplexing (ATTM);
Integrated Broadband Cable and Television Networks;
Converged Cable Access Platform Architecture

2 ETSI TR 101 546 V1.1.1 (2011-10)

Reference
DTR/ATTM-003015
Keywords
access, broadband, cable, data, IP, IPcable,
modem
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ETSI
3 ETSI TR 101 546 V1.1.1 (2011-10)
Contents
Intellectual Property Rights . 6
Foreword . 6
1 Scope . 7
2 References . 7
2.1 Normative references . 7
2.2 Informative references . 7
3 Definitions and abbreviations . 9
3.1 Definitions . 9
3.2 Abbreviations . 10
4 VOID . 12
5 CCAP Architecture Goals, Benefits and Overview . 12
5.1 Fundamental Goals of the CCAP . 12
5.2 CCAP Benefits . 13
5.2.1 Service Multiplexing Flexibilities . 13
5.2.2 Bandwidth Capacity and Density Gains . 14
5.2.3 High Reliability and Redundancy Capabilities . 14
5.2.4 Configuration and Management Simplifications . 14
5.2.5 Rack-Space and Power Reduction . 14
5.2.6 RF Combining Simplifications . 16
5.2.7 IP Router Integration . 16
5.3 Supported Services in CCAP. 16
5.3.1 Video EQAM Services . 16
5.3.1.1 Broadcast Digital Video . 17
5.3.1.2 Switched Digital Video . 17
5.3.1.3 Video on Demand . 17
5.3.2 DOCSIS Service s . 17
5.3.2.1 High-Speed Internet . 18
5.3.2.2 IPCablecom VoIP . 18
5.3.2.3 Transparent LAN Service . 18
5.3.2.4 Next Generation Video Services . 19
5.3.3 DOCSIS Provisioning of EPON . 19
5.4 CCAP Architectures . 19
5.4.1 Integrated CCAP Architecture . 19
5.4.1.1 CCAP MPEG Video Headend Reference Architecture . 19
5.4.1.2 CCAP Data Reference Architecture . 21
5.4.1.3 Modular Headend Architecture Functionality . 22
5.4.2 Modular CCAP Architecture . 22
5.4.2.1 Modular CCAP Functional Architecture . 22
5.4.2.2 Packet Shelf Functionality . 23
5.4.2.3 Access Shelf Functionality . 23
5.4.2.4 Modular CCAP Data/Video Architecture . 23
5.4.2.5 Downstream-Only Access Shelf . 24
6 Summary of DOCSIS Specifications and Applicability . 24
6.1 DOCSIS 3.0 Specifications . 24
6.1.1 MAC and Upper Layer Protocols Interface Specification v3.0 . 24
6.1.2 Physical Layer Specification v3.0 . 24
6.1.3 DOCSIS Security Specification v3.0 . 25
6.2 CCAP Specifications . 25
6.2.1 CCAP Operations Support System Interface . 25
6.2.1.1 SNMP Requirements and Reporting Requirements . 25
6.2.1.2 CCAP Object Model . 25
6.2.2 Packet Shelf to Access Shelf Interface Specification . 25
6.3 Modular Headend Architecture Specifications . 26
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4 ETSI TR 101 546 V1.1.1 (2011-10)
6.3.1 Edge Resource Management Interface Specification . 26
6.3.2 DOCSIS Timing Interface Specification . 26
6.3.3 Video Stream Interface Specification . 26
6.4 Downstream RF Interface Specification . 26
6.5 DOCSIS Set-Top Gateway Specification . 27
6.6 Business Services over DOCSIS Specifications. 27
6.6.1 Layer 2 VPN Specification . 27
6.6.2 TDM Emulation Interface Specification . 27
6.7 DOCSIS Provisioning of EPON Specifications . 27
6.7.1 DOCSIS Provisioning of EPON Architecture Specification . 27
6.7.2 DOCSIS Provisioning of EPON MEF Specification . 27
6.7.3 DOCSIS Provisioning of EPON MAC and Upper Layer Protocols Specification . 27
6.7.4 DOCSIS Provisioning of EPON Operations Administration and Maintenance Specification. 27
6.7.5 DOCSIS Provisioning of EPON Operations Support System Interface Specification . 27
6.7.6 DOCSIS Provisioning of EPON Physical Layer Specification . 28
6.7.7 DOCSIS Provisioning of EPON Security Specification . 28
6.8 Summary of DOCSIS Specification Applicability . 28
7 CCAP Features and Capabilities . 28
7.1 Service Multiplexing Capabilities . 28
7.1.1 CCAP Service Groups . 28
7.1.1.1 Broadcast Service Groups . 28
7.1.1.2 Switched Digital Video Narrowcast Service Groups . 29
7.1.1.3 VOD Narrowcast Service Groups . 29
7.1.1.4 DOCSIS Narrowcast Service Groups. 29
7.2 Optional Content Protection . 29
7.2.1 Network Decryption . 30
7.2.2 Access Encryption . 30
7.3 QAM Replication . 30
7.4 Spectrum Surveillance . 31
7.5 CCAP Configuration Management . 31
7.5.1 YANG Data Modelling Language and XML Background . 31
7.5.2 Configuration Object Model . 32
7.5.3 Configuration Data Model . 32
7.5.4 CCAP Configuration File Processing . 32
7.5.5 CCAP NETCONF-Based Configuration . 32
7.6 PON Configuration: DOCSIS Provisioning of EPON . 32
7.6.1 The DOCSIS and DPoE Networks . 33
7.6.2 DPoE Provisioning and Management . 34
7.6.3 Provisioning and Management of OLT Devices . 34
7.7 Protocol Support . 34
7.7.1 IP Versions. 34
7.7.2 VPN . 34
7.7.2.1 MPLS . 35
7.7.2.2 Multicast VPN (MVPN) . 35
7.7.3 Routing . 35
7.7.4 Multicast . 35
7.7.5 Modular CCAP: Packet to Access Shelf Interface (PASI) Protocols . 36
7.7.5.1 PASI Management Plane . 36
7.7.5.2 PASI Control Plane . 37
7.7.5.3 PASI Data Plane . 37
8 CCAP Implementations . 38
8.1 CCAP Interface Options . 38
8.1.1 Hybrid-Fibre Coax Interfaces . 38
8.1.1.1 Downstream RF Interfaces . 38
8.1.1.2 Upstream RF Interfaces . 38
8.1.2 Ethernet Passive Optical Network (EPON) Interfaces . 39
8.1.2.1 Split Ratios and Customers Served . 39
8.1.2.2 EPON Redundancy . 39
8.1.2.3 EPON Connectors . 39
8.1.3 Network Side Interface . 39
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5 ETSI TR 101 546 V1.1.1 (2011-10)
8.2 Platform Implementation Options . 40
8.2.1 I-CCAP Chassis Sizing . 40
8.2.2 M-CCAP Chassis Sizing and Physical Locations . 40
History . 44

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6 ETSI TR 101 546 V1.1.1 (2011-10)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://ipr.etsi.org).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Report (TR) has been produced by ETSI Technical Committee Access, Terminals, Transmission and
Multiplexing (ATTM).
ETSI
7 ETSI TR 101 546 V1.1.1 (2011-10)
1 Scope
The present document is intended to provide an introduction to the Converged Cable Access Platform (CCAP)
architecture. The CCAP architecture has been specified in an integrated and a modular implementation. The present
document describes both the integrated and modular architectures and discusses the various specifications that contain
normative requirements pertaining to the CCAP. In addition, the present document describes the architectural entities
and interfaces that make up the integrated and modular implementations, as well as the protocols they support. For the
modular implementation, the present document provides an overview of the operation of Packet Shelf and Access Shelf
devices, as well as the interface between them.
2 References
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
2.1 Normative references
The following referenced documents are necessary for the application of the present document.
Not applicable.
2.2 Informative references
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] ETSI EN 302 878-3: "Access, Terminals, Transmission and Multiplexing (ATTM); Third
Generation Transmission Systems for Interactive Cable Television Services - IP Cable Modems;
Part 3: Downstream Radio Frequency Interface; DOCSIS 3.0".
[i.2] DOCSIS Set-top Gateway (DSG) Interface Specification: "CM-SP-DSG", Cable Television
Laboratories, Inc.
[i.3] DOCSIS Timing Interface Specification: "CM-SP-DTI", Cable Television Laboratories, Inc.
[i.4] Edge QAM Video Stream Interface Specification: "CM-SP-EQAM-VSI", Cable Television
Laboratories, Inc.
[i.5] DOCSIS Edge Resource Manager Interface: "CM-SP-ERMI", Cable Television Laboratories, Inc.
[i.6] IEEE Standard for Information technology: "Telecommunications and information exchange
between systems-Local and metropolitan area networks-Specific requirements-Part 3: Carrier
Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical Layer
Specifications Amendment: Media Access Control (MAC) Parameters, Physical Layers, and
Management Parameters for 10 Gbs Operation".
[i.7] IEEE Std 802.3ba-2010: "IEEE Standard for Information Technology Specific Requirements -
Part 3: 40Gb/s and 100Gb/s Ethernet".
[i.8] Business Services over DOCSIS: "Layer 2 Virtual Private Networks", CM-SP-L2VPN, Cable
Television Laboratories, Inc.
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8 ETSI TR 101 546 V1.1.1 (2011-10)
[i.9] ETSI EN 302 878-4: "Access, Terminals, Transmission and Multiplexing (ATTM); Third
Generation Transmission Systems for Interactive Cable Television Services - IP Cable Modems;
Part 4: MAC and Upper Layer Protocols; DOCSIS 3.0".
[i.10] Operations Support System Interface Specification: "CM-SP-OSSIv3.0", Cable Television
Laboratories, Inc.
[i.11] ETSI EN 302 878-2: "Access, Terminals, Transmission and Multiplexing (ATTM); Third
Generation Transmission Systems for Interactive Cable Television Services - IP Cable Modems;
Part 2: Physical Layer; DOCSIS 3.0".
[i.12] IETF RFC 2328/STD0054: "OSPF Version 2", April 1998.
[i.13] IETF RFC 2453/STD0056: "RIP Version 2", November 1998.
[i.14] IETF RFC 3209 RSVP-TE: "Extensions to RSVP for LSP Tunnels", December 2001.
[i.15] IETF RFC 3376: "Internet Group Management Protocol Version 3", October 2002.
[i.16] IETF RFC 4023: "Encapsulating MPLS in IP or Generic Routing Encapsulation (GRE)",
March 2005.
[i.17] IETF RFC 4364: "BGP/MPLS IP Virtual Private Networks (VPNs)", February 2006.
[i.18] IETF RFC 5420: "Encoding of Attributes for MPLS LSP Establishment Using Resource
Reservation Protocol-Traffic Engineering (RSVP-TE)", February 2009.
[i.19] IETF RFC 4448: "Encapsulation Methods for Transport of Ethernet over MPLS Networks",
April 2006.
[i.20] IETF RFC 4601: "Protocol Independent Multicast - Sparse Mode (PIM-SM): Protocol
Specification (Revised)", August 2006.
[i.21] IETF RFC 4664: "Framework for Layer 2 Virtual Private Networks (L2VPNs)", September 2006.
[i.22] IETF RFC 4724: "Graceful Restart Mechanism for BGP", January 2007.
[i.23] IETF RFC 4761: "Virtual Private LAN Service (VPLS) Using BGP for Auto-Discovery and
Signalling", January 2007.
[i.24] IETF RFC 4874: "Exclude Routes - Extension to Resource Reservation Protocol-Traffic
Engineering (RSVP-TE)", April 2007.
[i.25] IETF RFC 5036: "LDP Specification", October 2007.
[i.26] IETF RFC 5303: "Three-Way Handshake for IS-IS Point-to-Point Adjacencies", October 2008.
[i.27] IETF RFC 5709: "OSPFv2 HMAC-SHA Cryptographic Authentication", October 2009.
[i.28] IETF RFC 5711: "Node Behavior upon Originating and Receiving Resource Reservation Protocol
(RSVP) Path Error Messages", January 2010.
[i.29] ETSI EN 302 878-5: "Access, Terminals, Transmission and Multiplexing (ATTM); Third
Generation Transmission Systems for Interactive Cable Television Services - IP Cable Modems;
Part 5: Security Services; DOCSIS 3.0".
[i.30] TDM Emulation Interface Specification: "CM-SP-TEI-I06", Cable Television Laboratories, Inc.
[i.31] IETF RFC 6020: "YANG - A Data Modelling Language for the Network Configuration Protocol
(NETCONF)".
[i.32] Data-Over-Cable Service Interface Specifications: "CCAP Operations Support System Interface
Specification", CM-SP-CCAP-OSSI, Cable Television Laboratories, Inc.
[i.33] DOCSIS Provisioning of EPON Architecture: "DPoE-SP-ARCHv1.0", Cable Television
Laboratories, Inc.
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9 ETSI TR 101 546 V1.1.1 (2011-10)
[i.34] DOCSIS Provisioning of EPON MEF Specification: "DPoE-SP-MEFv1.0", Cable Television
Laboratories, Inc.
[i.35] DOCSIS Provisioning of EPON MULPI Specification: "DPoE-SP-MULPIv1.0", Cable Television
Laboratories, Inc.
[i.36] DOCSIS Provisioning of EPON OAM Specification: "DPoE-SP-OAMv1.0", Cable Television
Laboratories, Inc.
[i.37] DOCSIS Provisioning of EPON OSSI Specification: "DPoE-SP-OSSIv1.0", Cable Television
Laboratories, Inc.
[i.38] DOCSIS Provisioning of EPON Physical Layer Specification: "DPoE-SP-PHYv1.0", Cable
Television Laboratories, Inc.
[i.39] DOCSIS Provisioning of EPON Security Specification: "DPoE-SP-SECv1.0", Cable Television
Laboratories, Inc.
[i.40] EQAM Architectural Overview Technical Report: "CM-TR-MHA", Cable Television
Laboratories, Inc.
[i.41] CCAP Packet Shelf to Access Shelf Interface Specification: "CM-SP-CCAP-PASI", Cable
Television Laboratories, Inc.
[i.42] IETF RFC 3810: "Multicast Listener Discovery Version 2 (MLDv2) for IPv6", June 2004.
[i.43] IETF RFC 4741: "NETCONF Configuration Protocol", December 2006.
[i.44] IETF RFC 4760: "Multiprotocol Extensions for BGP-4", January 2007.
[i.45] IETF RFC 5120: "M-ISIS: Multi Topology (MT) Routing in Intermediate System to Intermediate
Systems (IS-ISs)", February 2008.
[i.46] 802.3ah-2004: "IEEE Standard for Information Technology - Telecommunications and
information exchange between systems - Local and metropolitan area networks - Specific
requirements - Part 3: Carrier Sense Multiple Access With Collision Detection (CSMA/CD)
Access Method and Physical Layer Specifications Amendment: Media Access Control Parameters,
Physical Layers, and Management Parameters for Subscriber Access Networks".
[i.47] 802.1Q-2003: "IEEE Standards for Local and Metropolitan Area Networks: Virtual Bridged Local
Area Networks".
[i.48] 802.3av-2009: "IEEE Standard for Information technology-- Telecommunications and information
exchange between systems--Local and metropolitan area networks-- Specific requirements Part 3:
Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and Physical
Layer Specifications Amendment 1: Physical Layer Specifications and Management Parameters
for 10 Gb/s Passive Optical Networks".
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
Access Shelf (AS): one of the two chassis that make up a Modular CCAP implementation. The Access Shelf is
primarily responsible for MPEG processing and access functions (PHY, PON, etc.) normally associated with the CMTS
and the Edge QAM
Cable Modem Termination System (CMTS): headend component that provides the operator network side termination
for the DOCSIS link. A CMTS communicates with a number of Cable Modems to provide data services
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10 ETSI TR 101 546 V1.1.1 (2011-10)
Converged Cable Access Platform (CCAP): headend component that provides the functionality of a CMTS and an
Edge QAM in a single architecture with greater QAM density and overall capacity
Edge QAM (EQAM): head-end or hub device that receives packets of digital video or data from the operator network.
It re-packetizes the video or data into an MPEG transport stream and digitally modulates the transport stream onto a
downstream RF carrier using QAM
Ethernet Passive Optical Network (EPON): point-to-multipoint, fibre to the premises network architecture in which
unpowered optical splitters are used to enable a single optical fibre to serve multiple premises
hybrid fibre-coax System: broadband bidirectional shared-media transmission system using optical fibre trunks
between the head-end and the fibre nodes, and coaxial cable distribution from the fibre nodes to the customer locations
NETCONF: IETF network management protocol that provides mechanisms to manipulate the configuration of a
device. NETCONF executes YANG-based XML files containing configuration objects
Packet Shelf (PS): one of the two chassis that make up a Modular CCAP implementation. The Packet Shelf is
responsible for the packet processing functions, such as subscriber management, service flow management, layer-3
routing and higher layer protocol manipulation, as well as Access Shelf command and control
RF combiner: headend equipment that accepts multiple input signals and delivers a single output that is equal in phase
and amplitude
service group: set of channels for a given service (e.g. Video On Demand, High-Speed Internet) delivered via a number
of fibre nodes to corresponding subscribers of that service to a single subscriber device
YANG: language used to model data for the NETCONF protocol. A YANG module defines a hierarchy of data which
can be used for NETCONF-based operations, including configuration, state data, remote procedure calls (RPCs), and
notifications
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AES Advanced Encryption Standard
ANCP Access Node Control Protocol
AS Access Shelf
ASM Any-Source Multicast
AWGN Additive White Gaussian Noise
BGP Border Gateway Protocol
CA Conditional Access
CATV Cable Television
CBR Constant Bit Rate
CCAP Converged Cable Access Platform
CLI Command-Line Interface
CM Cable Modem
CMTS Cable Modem Termination System
CPE Customer Premises Equipment
CSA Common Scrambling Algorithm
DES Data Encryption Standard
DHCP Dynamic Host Configuration Protocol
DLC Downstream Line Card
DOCSIS Data-Over-Cable Service Interface Specifications
DPIC Downstream Physical Interface Card
DPoE DOCSIS Provisioning of EPON (Ethernet Passive Optical Network)
DRFI Downstream RF Interface
DSG DOCSIS Set-top Gateway
DTI DOCSIS Timing Interface
ECM Encryption Control Message
ECMD ECM Decoder
ECMG ECM Generator
EoC Ethernet over Coax
EPL Ethernet Private Line
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11 ETSI TR 101 546 V1.1.1 (2011-10)
EPON Ethernet Passive Optical Network
EQAM Edge QAM
ERM Edge Resource Manager
ERMI Edge Resource Manager Interface
EVPL Ethernet Virtual Private Line
EXP Experimental
FFT Fast Fourier Transform
Gbps Gigabits per second
GigE Gigabit Ethernet
GRE Generic Routing Encapsulation
HFC Hybrid Fibre/Coaxial
HSI High-Speed Internet
I-CCAP Integrated CCAP
ID Identifier
IETF Internet Engineering Task Force
IGMP Internet Group Management Protocol
IP Internet Protocol
IPDR IP Detail Record
ISIS Intermediate System to Intermediate System
IS-IS Intermediate System To Intermediate System Protocol
L2VPN Layer 2 Virtual Private Network
LAN Local Area Network
LDP Label Distribution Protocol
LSP Label-Switched Path
MAC Media Access Control
M-CCAP Modular CCAP
M-CMTS Modular CMTS
MCX Micro Coaxial
MEF Metro Ethernet Forum
MHA Modular Headend Architecture
MHz Megahertz
MIB Management Information Base
MPEG Moving Picture Experts Group
MPLS Multiprotocol Label Switching
MPTS Multi-Program Transport Stream
MT Multi Topology
MULPI MAC and Upper Layer Protocols Interface
MVPN Multicast Virtual Private Network
NA Not Applicable
NNI Network to Network Interface
NSI Network-Side Interface
OAM Operations Administration and Maintenance
OLT Optical Line Termination
ONU Optical Network Unit
OOB Out Of Band
OSPF Open Shortest Path First protocol
OSS Operations Support System
OSSI Operations Support System Interface
OTT Over-the-Top
P2MP Point-to-Multipoint
PASI Packet to Access Shelf Interface
PC Physical Contact
PCR Program Clock Reference
PE Provider Edge
PE-CE Provider-Edge - Customer-Edge
PEG Public, Education, and Government channels
PHY Physical Layer
PIC Physical Interface Card
PIM-DM Protocol Independent Multicast - Dense Mode
PIM-SM Protocol Independent Multicast - Sparse Mode
PON Passive Optical Network
PS Packet Shelf
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12 ETSI TR 101 546 V1.1.1 (2011-10)
PSTN Public Switched Telephone Network
QAM Quadrature Amplitude Modulation
QoS Quality of Service
QPSK Quadrature Phase Shift Keying
RF Radio Frequency
RFC Request for Comments
RFoG Radio Frequency over Glass
RIP Routing Information Protocol
RSVP Resource Reservation Protocol
RSVP-TE RSVP - Traffic Engineering
SC Subscriber Connector
SCTE Society of Cable Telecommunications Engineers
SDV Switched Digital Video
SIP Session Initiation Protocol
SNMP Simple Network Management Protocol
SPTS Single Program Transport Stream
SRM Session Resource Manager
SSM Source-Specific Multicast
STB Set-Top Box
TDM Time-Division Multiplexing
TEI TDM Emulation Interface
TLS Transparent LAN Service
TTL Time-To-Live
UCH Universal Cable Holder
UDP User Datagram Protocol
UML Unified Modelling Language
VBR Variable Bit Rate
VLAN Virtual LAN
VOD Video On Demand
VoIP Voice over IP
VPLS Virtual Private LAN Service
VPN Virtual Private Network
VSI Video Stream Interface
XML Extensible Markup Language
4 VOID
5 CCAP Architecture Goals, Benefits and Overview
5.1 Fundamental Goals of the CCAP
The Converged Cable Access Platform (CCAP) is intended to provide a new equipment architecture option for
manufacturers to achieve the Edge QAM and CMTS densities that cable operators require in order to address the costs
and environmental challenges resulting from the success of narrowcast services. The CCAP leverages existing
technologies, including DOCSIS 3.0, Modular Headend Architecture, and current HFC architectures; and also can
include newer ones, such as Ethernet optics and EPON (Ethernet Passive Optical Network).
The CCAP provides an alternative approach to the implementation of converged video and data services described in
the Modular Headend Architecture (MHA) Technical Report (i.e. Modular CMTS with Universal Edge QAM). Similar
to MHA, the CCAP provides sharing of QAM channels for different narrowcast services, but adds the capability of
sharing broadcast QAM channels.
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13 ETSI TR 101 546 V1.1.1 (2011-10)
The key functional goals for CCAP include:
• Flexible use of QAM channels for the various services offered by cable operators, enabling modification to the
number of QAMs using MPEG transport stream-based services (e.g. for VOD, SDV, etc.) versus DOCSIS-
based services (e.g. HSI, voice, video over IP, etc.) over time though a single configuration point.
• Individually configurable assignment of QAM channels to various service groups, such that it would be
possible to have HSI/voice service groups, VOD service groups, and/or SDV service groups overlap in
different ways without requiring that these service groups be identical.
• Efficient implementation of separate sets of QAM channels for narrowcast and broadcast applications, such
that QAM channels for narrowcast services can be individually implemented for each RF port, and QAM
channels used for broadcast services can be shared among the RF ports in each downstream line card (DLC).
• Simplification of the RF combiner network by providing all QAM channels for all digital services from a
single RF port, only leaving certain legacy functions for RF combining.
• Option to add content scrambling - both standardized and proprietary (e.g. PowerKEY™, DigiCipher®, etc.) -
without requiring special-purpose hardware, such that a CCAP from any vendor can optionally implement the
appropriate scrambling mechanisms without increasing the complexity of the platform.
• A transport-agnostic network architecture allowing implementation of EPON and other access network
technologies natively within the CCAP. The CCAP will be expected to support additional access technologies
and higher capacity uplink interfaces in the future with pluggable or otherwise replaceable components,
allowing upgrade to a new access technology via installation or replacement of access modules.
• Modularization of the software environment, allowing upgrades to be applied to specific services without
impacting other services. This partitioning also helps to ensure that software issues in the implementation of a
given service do not necessarily impact other partitioned services.
• Significant operational improvements, including environmental efficiencies (e.g. reduced space, power
consumption, and heat dissipation), implementation of functions such as upstream health monitoring,
continuous wave carriers for plant amplifier biasing, and many other operational enhancements.
The CCAP can be implemented as a single integrated chassis or implemented in a "modular" fashion, consisting of
more than one device. Despite the multiple chassis approach, a modular CCAP (M-CCAP) is seen and managed as a
single network entity by the operations support system (OSS). Multiple different modular architectures are possible and
permitted, provided they appear and are managed as a single network entity. However, for the purposes of the present
document, an M-CCAP is defined as an architecture that is composed of two types of devices:
• A single Packet Shelf (PS) that contains the packet processing functions, such as subscriber management,
service flow management, layer-3 routing and higher layer protocol manipulation.
• One or more Access Shelves (AS) that contains the upstream and downstream PHY functions normally
associated with the CMTS and the Edge QAM, and nearly all of the DOCSIS MAC.
5.2 CCAP Benefits
Whether implemented in an integrated chassis or in a modular manner, the CCAP provides the following operational
benefits.
5.2.1 Service Multiplexing Flexibilities
The CCAP provides efficient implementation of Edge QAM (EQAM) blocks by implementing separate sets of QAM
channels for narrowcast and broadcast applications. QAM channels for narrowcast services are individually
implemented for each RF port, while QAM channels used for broadcast services are shared among all the RF ports in
each downstream line card (DLC). The number of narrowcast and broadcast QAMs supported on each RF port is
flexible.
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14 ETSI TR 101 546 V1.1.1 (2011-10)
The CCAP provides the ability to map narrowcast and broadcast QAMs in different combinations to specific
downstream ports via configuration. The same narrowcast video QAM can be mapped to multiple downstream ports,
allowing for overlap of SDV and VOD service groups. This allows an operator to create service groups on a decoupled,
service-by-service basis and effectively deal with service group inequalities.
The CCAP can configure any QAM in a given CCAP RF port for DOCSIS or Edge QAM applications. This allows all
QAMs for a given service group to be generated from a single RF port. By allowing the configuration of any QAM on
any RF port for broadcast, SDV, VOD, or DOCSIS, the CCAP provides the ability to transition to next generation video
services (via DOCSIS or a new access technology) as necessary.
5.2.2 Bandwidth Capacity and Density Gains
The CCAP is designed to greatly increase the capacity of a single edge device, delivering all narrowcast and broadcast
services via the downstream RF ports deployed (15-20 downstream ports on a small chassis; 40-60 on a larger chassis).
The CCAP is expected to support multiple 10, 40, and/or 100 GigE interfaces with the ability to support a downstream
capacity of over 150 Gbps. On a typical downstream line card in a large CCAP chassis, this traffic will be utilized by up
to 12 downstream RF ports. QAM channels are flexible across service types. Each downstream port is capable of
supporting up to 158 QAM channels. For example, a port could have 64 narrowcast QAMs and 96 broadcast QAMs.
Each upstream port is capable of supporting a minimum of 4 DOCSIS RF upstream channels, with 6 channels being a
recommended implementation. Support for higher data rates is possible with implementation of newer access
technologies, such as EPON via DPoE. The ratio of downstream to upstream ports is variable, with an expected ratio of
2 upstream ports for every downstream port.
5.2.3 High Reliability and Redundancy Capabilities
Given the scope of each RF port providing all services for a given service group, it is important that the operation be
highly reliable. Therefore, a CCAP is expected to support redundancy for critical components; however, even in a non-
redundant configuration, the CCAP should provide sufficient up time. This, coupled with management of service group
size, allows the size of failure groups to be reduced.
The CCAP is designed with a "wire once" approach: physical interface cards (PICs) implement the upstream and
downstream physical interfaces, allowing replacement of line cards without impact to the cabling. N+1 redundancy
allows line card replacement without impacting services for longer than the failover time and without the need to re-
wire upstream and downstream connections. This reduces mean time to recovery for the CCAP.
The CCAP is designed such that software upgrades can be performed against a specific functional module, allowing an
upgrade to a specific service that does not impact other services on the CCAP. Previous versions of the
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