Installation guide

Release Notes for Cisco uBR7200 Series for Cisco IOS Release 12.1 T

78-10643-04 Rev. B0

System Requirements

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CM-initiated dynamic MAC messages: Dynamic Service Addition (DSA) and Dynamic

Service Deletion (DSD). These messages allow dynamic SIDs to be created and deleted at

run-time on a per-VoIP call basis.

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Unsolicited grant service (constant bit-rate scheduling) on the upstream: This helps provide a

higher-quality channel for upstream VoIP packets from an Integrated Telephony Cable Modem

(ITCM) such as the Cisco uBR924 Cable Access Router.

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Ability to provide separate downstream rates for any given ITCM, based on the IP-precedence

value in the packet: This helps separate voice signaling and data traffic that goes to the same

ITCM to address rate shaping purposes.

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Concatenation—To increase the per-CM upstream throughput in certain releases of software,

Cisco uBR7200 series software supports a concatenated burst of multiple MAC frames from a

CM that supports concatenation.

Note All DOCSIS 1.0 extensions are activated only when a CM or Cisco uBR924 that

supports these extensions solicits services via dynamic MAC messages or the

feature set. If the CMs in your network are pure DOCSIS 1.0-based, they will

receive regular DOCSIS 1.0 treatment from the CMTS.

• Clock Synchronization

The Cisco uBR7200 series support clock hardware and software to enable high-quality delivery of

IP telephony services through synchronized data transmissions. To support the clock feature set, a

Cisco uBR7246 VXR chassis must be used. The Cisco uBR7246 VXR must contain a clock card

and an MC16S or MC16E Cable Modem Card. Only the MC16S and the MC16E Cable Modem

Cards support the external clock reference from the clock card to distribute that signal to CMs or

set top boxes (STBs) attached to the specific network segments. The chassis must be running Cisco

IOS Release 12.1(1a)T1 or higher.

Each cable modem must also support VoIP applications and the clock reference feature set to enable

synchronized timing. The Cisco uBR924 Cable Access Router, running Cisco IOS

Release 12.0(7)T or later, supports the clock reference feature set automatically.

Hardware Supported

Cisco IOS Release 12.1(5)T supports the following Cisco uBR7200 Series Universal Broadband

Routers:

• Cisco uBR7223

• Cisco uBR7246

• Cisco uBR7246 VXR

For detailed descriptions of the new hardware features, see the “New and Changed Information” section

on page 18.