Installation guide

44
Release Notes for Cisco uBR7200 Series for Cisco IOS Release 12.1 T
78-10643-04 Rev. B0
Caveats
Workaround: It is recommended that the user not use this non default upstream channel setting of
128 ticks/mslot, channel width = 200000, until an image with the fix is available. The problem will
NOT happen with the default setting of minislot size = 8 ticks, channel width = 1600000. However,
if for any reason user MUST use minislot size = 128 ticks, the following hidden command can be
used to allow CMs to complete initial ranging.
cmts(config-if)#no cable downstream map-guardband
However, the above workaround can cause a non optimal operation of the upstream burst receiver.
Some CRC errors/No energy detection problem can be produced as a side result of the workaround.
Thus, the workaround is recommended only if the user MUST use minislot size=128 ticks.
This is resolved in Cisco IOS Release 12.1(2)T.
• CSCdr47549
An upstream reset function that was added for MC16E cards caused MC16B cards to lose upstream.
This is resolved in Cisco IOS Release 12.1(2)T.
• CSCdr23835
If at least three cable interfaces were configured in a bundle and the bundle master was not the
lowest-numbered cable interface, removing one of the slave interfaces from the bundle followed by
removing another slave caused a crash. This is resolved in Cisco IOS Release 12.1(2)T.
• CSCdr23090
If a frequency hop was triggered on an upstream port serving constant bit rate (CBR) slots, the
Cisco uBR7200 series router crashed. This is resolved in Cisco IOS Release 12.1(2)T.
• CSCdr19087
In bundling, if the IP address on the master interface was configured with certain values, modems
on all cable interfaces within the bundle were not able to pass the CM initialization phase. This is
resolved in Cisco IOS Release 12.1(2)T.
• CSCdr13184
A problem occurred when there was simultaneous traffic to the same CM with different IP
precedence rate limits, which are configured by using the Cisco Vendor-specific subtype IP
precedence rate limit. This is resolved in Cisco IOS Release 12.1(2)T.
• CSCdp98512
If a Cisco uBR7200 Series Universal Broadband Router had non compliant DOCSIS CMs on an
upstream port that ranged with a negative timing offsets, the modems deceived the CMTS Map
building code into using a large Map Advance when the dynamic Map Advance algorithm was
active on each upstream port.
The result of this situation was that all other CMs on that upstream port were unable to send data
upstream to the CMTS and went offline. The router generated a warning log message every time a
CM with bad timing offset was detected. A sample warning message follows:
%UBR7200-5-BADTXOFFSET:Bad timing offset -10 detected for cable modem 0010.9500.0a6a
This is resolved in Cisco IOS Release 12.1(2)T.
• CSCdp89661
If an administrator tried to delete a CMTS-created static QoS profile used for G.729 or G.711
upstream CBR service, the CMTS prevented destruction of such profiles. The Cisco uBR7200
crashed when the first Voice/Fax call using the undeleted profile terminated. This is resolved in
Cisco IOS Release 12.1(2)T.