Specifications

Release Notes for Cisco uBR924 Cable Access Router for Cisco IOS Release 12.1(5)T

OL-0385-04 Rev. B0 (2/2001)

Caveats

• CSCdp13089 and CSCdp90276

The voice-port cptone command does not support the set of telephony tones used in the Czech

Republic or in Switzerland. There is no workaround.

• CSCdr28707

The show interface command can show an impossible number of CRC errors on the cable interface

when transmitting VoIP traffic. When this error occurs, the number of cyclic redundancy check

(CRC) errors typically exceeds a billion errors and is greater than the total number of packets

transmitted on the interface. The workaround is to use the show interface cable 0 counters

command to display the correct number of errors.

• CSCdr45850 and CSCdr46128

The Cisco uBR924 Cable Access Router can crash when using an access list numbered 100 or 101

while running Cisco IOS Release 12.1 T images that support any form of IPSec encryption. Other

access lists, however, can be used without problem.

Workaround: Do not configure access list numbers 100 and 101 for any purpose. Use access lists

102 through 199 instead.

• CSCdr74817

Using the ip pim interface command on the cable interface can force the Cisco uBR924 to go

off-line. The workaround is to avoid enabling IP multicast on the cable interface using the ip pim

interface command.

• CSCdr76711

Upstream performance for data traffic on a DOCSIS 1.0 cable modem is limited to approximately

1.7 megabits per second, due to the limits of using one SID for data traffic, as required by the

DOCSIS 1.0 specification. This caveat cannot be resolved until the implementation of the DOCSIS

1.1 specification, which provides for multiple SIDs for data traffic. There is no workaround.

• CSCds74274

The Value Small Office image (ubr920-k1o3v4y556i-mz) should be used only if BPI is disabled;

otherwise, the cable access router might reload, requiring power cycling and reconfiguration before

it can come back online. There is no workaround.

Closed or Resolved Caveats—Release 12.1(5)T and Earlier Releases

All the caveats listed in this section are closed or resolved in Release 12.1(5)T:

• CSCdp04541

Previously, the Cisco uBR924 Cable Access Router would age out a CPE device’s MAC address

after one week of inactivity. This behavior did not conform to the DOCSIS specification, which

prohibits aging out of CPE devices.

This is resolved in Cisco IOS Release 12.1(1), so that CPE devices are no longer aged out.

• CSCdp25025 and CSCdr11675

These caveats improve the Cisco uBR924 router’s error handling when it does not receive a valid

response from the time-of-day (ToD) server during its power-on provisioning; an error message is

also displayed when a ToD failure occurs. These caveats also add support for using multiple ToD

servers when the DHCP server returns a list of two or more ToD servers.

This caveat is resolved in Cisco IOS Release 12.1(1)T.