Transcript DOCSIS IP-video Bypass Architecture (DIBA) an Architecture for

DOCSIS IP-video Bypass Architecture
(DIBA)
an Architecture for IPTV over Cable
Speaker:陳羿仲
Advisor:吳和庭
2012/4/10
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Outline
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Introduction
Modular CMTS for IP-Video
DOCSIS IP-video Bypass Architecture (DIBA)
DIBA development network
CONTROL PLANE: DIBA LEVERAGES STANDARD
PCMM AND CMTS FUNCTIONS
• Over-the-top video
• References
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Introduction
• IPTV
• Data over Cable Service Interface Specification
(DOCSIS)
• Video on Demand (VoD)
• MPEG
• EdgeQAM (E-QAM) modulator
• Cable Modem Termination System (CMTS)
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Modular CMTS for IP-Video
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The DOCSIS Modular-CMTS (M-CMTS) architecture defined a common EdgeQAM (E-QAM) architecture in which the E-QAMs are separate from the CMTS
core.
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The CMTS core does much of the DOCSIS downstream processing, but the final
DOCSIS downstream emerges from the E-QAM.
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A strategy of using M-CMTS to provide IPTV VoD would call for deploying MCMTS EQAMs for DV-VoD first, and adding M-CMTS core capacity as needed to
transition the digital video VoD to IPTV-VoD.
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The M-CMTS core capacity used for IPTV-VoD would quickly exceed the CMTS
capacity used for high speed data (HSD). A straightforward implementation of
M-CMTS for IPTV, therefore, will require many times the cost of MCMTS core
capacity as that currently used for HSD.
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DOCSIS IP-video Bypass Architecture (DIBA)
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The ‘Hairpin’ Cost
Designed for Economy
Video Encapsulation by DIBA Edge-QAMs
Encapsulation scheme for IP-video
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The ‘Hairpin’ Cost
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Video Encapsulation by DIBA EdgeQAMs
• instead of traveling from the edge (or last-hop) router to the CMTS, the
packets bypassthe CMTS and instead go to the DIBA Encapsulator/EdgeQAM
• Secondly, the DIBA EdgeQAM is modified to perform the necessary DOCSIS
framing on the incoming, video bearing IP packets
• The cable modem cannot distinguish these channels from equivalent ‘unsynchronized’ channels from a CMTS or MCMTS DEPI EdgeQAM
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Video Encapsulation by DIBA EdgeQAMs
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Encapsulation scheme for IP-video
• Encapsulation is the inclusion of one data structure within
another structure so that the first data structure is hidden for
the time being
• Generic Routing Encapsulation (GRE): defined by RFC 2784, is
a simple IP packet encapsulation protocol. A GRE tunnel is
used when IP packets need to be sent from one network to
another, without being parsed or treated like IP packets by
any intervening routers
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Encapsulation scheme for IP-video
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Design for Economy
• DIBA accomplishes the goals of the M-CMTS without the unnecessary
expense of the M-CMTS core processing. It also works with integrated
CMTSs
• Operators can deploy independently scalable numbers of downstream
channels without changing the MAC domain or the number of upstream
DOCSIS channels
• These downstream channels are available for VoD/IP and switched-digitalvideo/IP. They can also lower the cost to deliver video over DOCSIS service
to be competitive with today’s MPEG VoD
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Design for Economy
• A DOCSIS 3.0 cable modem can receive multiple downstream DOCSIS
channels, but only one needs to be fully functional at the MAC layer
• This primary or synchronized channel will convey the DOCSIS timestamps
to the CMs; manage ranging to provide the proper time-base to the cable
modem; instruct the cable modems when to transmit upstream; deliver
other MAC layer messages for cable modem registration, maintenance,
etc
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DIBA development network
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DIBA development network
• PacketCable is an industry consortium founded by CableLabs with the goal
of defining standards for the cable television modem access industry.
• Policy server is a security component of a policy-based network that
provides authorization services and facilitates tracking and control of files.
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CONTROL PLANE: DIBA LEVERAGES STANDARD
PCMM AND CMTS FUNCTIONS
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1. IPTV client requests IP video by way of a SIP invite, which passes first to the
Proxy-CSCF. The P-CSCF forwards the service request and QoS requirements to the
DIBA application manager. This information then passes to the PCMM policy server,
and finally to CMTS.
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2. CMTS checks authorization of CM for desired class of service and if QoS can be
supported.
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3. The CMTS requests the necessary additional downstream channel capacity on a
DIBA E-QAM from the Edge Resource Manager.
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4. The CMTS configures the CM for the appropriate DOCSIS channel and video flow
from the DIBA EdgeQAM.
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5. CMTS makes available certain additional fields necessary for DIBA encapsulation
by the Edge-QAM / Encapsulation Engine, e.g., the CPE MAC address. The CMTS
signals OK back to the Policy Server and DIBA Application Manager.
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CONTROL PLANE: DIBA LEVERAGES STANDARD
PCMM AND CMTS FUNCTIONS
• 6. The DIBA application manager configures the edge router so as to
identify the IP packets that are to be bypassed, e.g., based on the
source and destination IP addresses; source and destination Port
numbers; IP protocol type. Thus, instead of being forwarded to the
CMTS, packets of the new DIBA video flow will be tunneled to the
DIBA EdgeQAM, e.g., by a Generic Routing Encapsulation Tunnel.
• 7. The DIBA App Manager signals OK back to the P-CSCF
• 8. The P-CSCF then forwards the SIP INVITE to the IPTV Server,
which forwards it to the VoD server.
• 9. A SIP OK is sent from the VoD server back along this chain to the
IP set-top. The video flow begins.
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Over-the-top video
• over-the-top content (OTT) means on-line delivery of video
and audio without the Internet service provider (Comcast,
Verizon, etc.) being involved in the control or distribution of
the content itself
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Over-the-top video
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References
• Joyce, G.; Bao, J.; Patrick, M.; Flanagan, D. “DOCSIS IP-Video
Bypass Architecture (DIBA), an Architecture for IPTV over
Cable “, Consumer Communications and Networking
Conference, 2009. CCNC 2009. 6th IEEE
• Wikipedia
• RFC-2784
• Cablelabs : http://www.cablelabs.com/
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Thank you , Q&A
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