Cisco Cisco IOS Software Release 12.2(8)YN
13
New Software Features in Release 12.2(8)YN
OL-3406-01 Rev E0
New and Changed Information
Note
Do not use the tdm connected command when both a BRI VIC (VIC-2BRI-NT/TE) and an E1/T1 VWIC
(such as the VWIC-1MFT-E1) are present in the same MRP. BRI and E1/T1 ports require independent
clock sources.
(such as the VWIC-1MFT-E1) are present in the same MRP. BRI and E1/T1 ports require independent
clock sources.
Tip
It is recommended that the tdm connected command be used when there is only one T1 or E1 port
configured for voice (or for voice and data) installed in the system.
configured for voice (or for voice and data) installed in the system.
Multichannel Support
Entering the [no] tdm multichannel command enables multi-channel support. This command provides
support for up to a maximum of eight channel groups, PRI data (PRI-D) channels, or PRI dialer calls on
a single T1 or E1 controller on an MRP, with supported speeds on the individual channels of 48Kbps,
56Kbps, and 64Kbps. If multi-channel support is not enabled, speeds of 48Kbps and 56Kbps are not
supported.
support for up to a maximum of eight channel groups, PRI data (PRI-D) channels, or PRI dialer calls on
a single T1 or E1 controller on an MRP, with supported speeds on the individual channels of 48Kbps,
56Kbps, and 64Kbps. If multi-channel support is not enabled, speeds of 48Kbps and 56Kbps are not
supported.
Enter the following command to enable multi-channel support (this feature is not enabled by default):
tdm multichannel {E1/T1} slot/port number timeslots range
where range can be 1-24 or 1-31.
The default is to have all timeslots in Serial Channel Controller (SCC) non-multi-channel support mode.
If all four SCCs are engaged by multiple channel groups (multi-channel and non-multi-channel modes)
on one controller, all High-Level Data Link Control (HDLC) resources will be allocated and no
additional channel groups can be created on the remaining controller. This situation is caused by the
fragmentation of channel groups on the controller. To work around this problem, do not interleave SCC
and multi-channel modes under one controller; instead, use consecutive channels of either SCC or
multi-channel modes.
on one controller, all High-Level Data Link Control (HDLC) resources will be allocated and no
additional channel groups can be created on the remaining controller. This situation is caused by the
fragmentation of channel groups on the controller. To work around this problem, do not interleave SCC
and multi-channel modes under one controller; instead, use consecutive channels of either SCC or
multi-channel modes.
For example, to set up a total of 11 channels in multi-channel mode, you could enter a command similar
to the following:
to the following:
tdm multichannel [T1/E1] 1/0 timeslots 1-11 (multi-channel mode)
In this example, only one SCC will be used and all remaining timeslots on 1/0 will use up the second
available SCC. There will be two SCCs available for the second controller. If you fragment the groups
by entering multiple tdm multichannel commands, all four SCCs will be used by one controller, leaving
no available SCCs for the remaining controller.
available SCC. There will be two SCCs available for the second controller. If you fragment the groups
by entering multiple tdm multichannel commands, all four SCCs will be used by one controller, leaving
no available SCCs for the remaining controller.
Note
HDLC is a protocol that provides Cisco serial encapsulation. When using non-multi-channel mode, only
four HDLC resources are available. In multi-channel mode, eight HDLC resources are available.
four HDLC resources are available. In multi-channel mode, eight HDLC resources are available.
Echo Cancellation Enhancement
Cisco IOS Release 12.2(8)YN on the Cisco ICS 7750 introduces support for a G.168-2000-compliant
echo canceller, with up to 64 ms of coverage. The standard Cisco echo canceller, which supports 32 ms
of coverage, is used by default. To enable 64-ms echo cancellation, enter the following command, in
global configuration mode:
echo canceller, with up to 64 ms of coverage. The standard Cisco echo canceller, which supports 32 ms
of coverage, is used by default. To enable 64-ms echo cancellation, enter the following command, in
global configuration mode:
voice echo-canceller extended