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ISR 4K NIM 4MFT-T1/E1 - no "interface Serial"

Level 1
Level 1

I'm configuring a new 4K router with a 4MFT-T1/E1, with the intent of using it as a branch router connected to a 2xT1 MPLS link.  I followed the instructions found on on this Cisco page to the letter, but something's still not right.  I had no issues defining the card type or the controllers, nor did I have a problem creating the Multilink interface.  However, I cannot configure the serial interfaces - "serial" is not an option under the "interfaces" command context.


R4261-1(config)# int serial ?

% Unrecognized command


The card does appear when I do a "show inventory."  Also, the T1s appear in a "show controllers" command output.

1 Accepted Solution

Accepted Solutions

Level 1
Level 1


You need to define the channel-group with the timeslots in the controller (in case you're using that T1 as a Data Interface):


channel group channel-group-number {timeslots range [speed kbps ] | unframed }


Or in case you're using it for voice you define it as a ds0-group or pri-group:


ds0-group ds0-group-number timeslots timeslot-list type {e&m-delay-dial e&m-immediate-start e&m-wink-start fxo-ground-start fxo-loop-start fxs-ground-start fxs-loop-start


Both configuration examples are on that same link you posted. When you do this it will create the interface you need with the channel-group / ds0-group number, for example:


If you create channel-group 1 and your card is on slot 0/0/0 it will create a Serial 0/0/0:1 Interface

If you create ds0-group 2 and your card is on slot 0/1/0 it will create a voice-port 0/1/0:2 Interface


Hope that helps