Cisco Cisco IOS Software Release 12.2(11)YU

This section describes unexpected behavior in Release 12.2(11)YU.

If you are using ISDN PRI with MGCP on an MRP300 with two VWIC-1MFT-T1s, the PRI line that is 
associated with Slot 1 in the VWIC-1MFT-T1 will not work properly.

Workaround—Install a VWIC-2MFT-T1 in the MRP300 and leave the other MRP slot empty.

When a call to the PSTN is being made through MRP FXS and FXO interfaces on which the 
forward-digits all command has been entered, it is possible that the DTMF tones might be echoed back 
to the call originator, due to a suspected problem with the echo canceller. 

Workaround—Tuning the echo canceller settings and disabling the forward all digits functionality on 
the necessary FXS and FXO interfaces should help solve this problem. Refer to the following 
documentation for more information:

If you are using an MRP or ASI with an E1 or T1 CAS trunk, if you change the TDM clocking on an E1 
or T1 controller from an export clock configuration to an import clock configuration, and if the E1 or T1 
controller is shut down when its clocking is changed, then configuring a DS0 group and entering a no 
shut command on that controller will cause intermittent call failures on some time slots. 

For example, if interface T1 0/0 is configured as an export clock and interface T1 0/1 is also configured 
as an export clock, the following sequence of commands will cause intermittent call failures on T1 0/1:

    controller T1 0/0

    shutdown

    no ds0-group 0 timeslots 1-24

    no tdm clock T1 0/0

    controller T1 0/1

    shutdown

    no ds0-group 1 timeslots 1-24

    no tdm clock T1 0/1

    tdm clock T1 0/0 voice export line

    tdm clock T1 0/1 voice import T1 0/0 internal

    controller T1 0/0

    ds0-group 0 timeslots 1-24 type e&m-wink-start

    no shutdown

    controller T1 0/1

    ds0-group 1 timeslots 1-24 type e&m-wink-start

    no shutdown