Installation guide

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

78-10643-04 Rev. B0

New and Changed Information

Concatenation is enabled by default for current cable modem cards (see the “Cable Modem Cards”

section on page 9), but can be disabled with the Cisco IOS no cable upstream number

concatenation interface command. The show controller command displays whether concatenation

is enabled on an interface.

Note Concatenation is supported only with cable modems that support DOCSIS

concatenation.

• Embedded Client Signaling (dynamic SIDs)—Supports the dynamic creation, configuration, and

deletion of Service Identifiers (SIDs) to accommodate different classes of service. This allows

cable modems to request high-priority or high-bandwidth data streams as needed, such as when a

VoIP call is made.

Note Dynamic SIDs can be used only with cable modems that also support this

feature. Otherwise, cable modems must use the static SIDs supported in

previous releases.

• IP Precedence-Based Rate Limiting—In addition to the currently supported traffic shaping

techniques, Cisco IOS Release 12.1(1a)T1 supports a new configuration field that associates a

maximum bandwidth (in kbps) with a particular setting of the IP type of service (ToS) bits. This

can be used to ensure that certain traffic, such as data, does not exceed a preset rate limit and

thereby interfere with higher-priority real-time traffic, such as VoIP calls.

• Support for Unsolicited Grants—New fields in the DOCSIS configuration file can be used so that

when a cable modem requests a voice or fax SID, the MAC scheduler on the Cisco uBR7200 series

router schedules fixed periodic slots on the upstream for that traffic flow. The cable modem does

not have to contend for these slots, and because the Cisco uBR7200 series router controls the

timing of the slots, it has a very precise control over potential delay and jitter. This provides a

Constant Bit Rate (CBR) traffic flow for real-time traffic such as voice and fax calls.

In addition, the Cisco uBR7200 series router can create QoS profiles for G.711 fax traffic and

G.729 voice traffic. These profiles can be customized with the scheduling parameters required for

the G.711 and G.729 CODECs being used at the subscriber’s site.

Dynamic Mobile Hosts

This feature addresses a security hole that occurs when the Cisco uBR7200 router supports mobile

hosts. (Mobile host are hosts that can move from one modem to another modem). Anyone who knows

the MAC address of a mobile host can “fake” the mobile host, thereby causing denial of access for the

real mobile host.

To avoid this security hole, the Dynamic Mobile Hosts feature pings the mobile host on the old SID to

verify that the host has indeed been moved.

Enhanced Modem Status Display

The Cisco uBR7200 Series Universal Broadband Router supports polling of the cable modems to obtain

parameter and status information on an ongoing basis. Two new Cisco IOS commands are added to

support this feature.