T1 controller configuration

[sarahr202]

Hi everybody

Please consider the follwng example

R1  ------T1------------------R2

R1 has t1 controller in module/slot: 1/1

So if I configure T1 controller installed in( module/slot) , 1/1 ,with channel-group 1, will it create a serial int on R1 as:

int s1/1:1

I am trying to understand the syntax of serial interface created when we configure T1 controller card on a router.

Can i say

when we configure t1 controller card on a router it will create a serial  int as:

int s a/b: n

where a/b refers to  corresponding module/slot where T1 card is installed and "n" refers to number specified in channel group command.

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Let say we we want to connect R1 and R2 with T1 line. Both routers have t1 controller installed.

When we configure t1 controller cards on both routers ,do channel-group number has to mach on both routers ?

thanks and have a great day.

[Giuseppe Larosa · Accepted solution]

Hello Sarah,

generally speaking your understanding is correct.

However, there is a special case that is channel-group 0 unframed in this case if supported the group number must match and must be 0 and the corresponding serial interface will be ser x/y:0. ( This feature is hardware dependent not all t1/e1 controllers support the unframed option).

In all other cases, what really counts is the set of DS0 timeslots that are members of the channel-group: as you have noted the channel-group number can be different on the two routers, but they must agree on what timeslots to use or connectivity will be broken.

The DS0 timeslots identify exact positions in the framing structure of the signal for this the need of exact match.

In simple words if R1 uses a channel-group that uses timeslots 0-9 and the other device uses timeslots 10-19 each device sends in some positions that are not examined by the other side.

Hope to help

Giuseppe

[sarahr202]

thanks Giuseppe

So If R1 uses slots timeslots 1 through   5 while R2 uses timeslots 6 through 11. R2 will not examine the data sent by R1 because R2 is not checking these time slots i.e time slots1 through 5. Likewise, R1 will not examine the data sent by R2 because R1 is not checking these time slots i.e timeslots 6 through 11.

If above is correct, then it means when we use channel -group 1 timeslots 1-5 on R1, We are telling R1 use time slots 1-5 for sending and receiving data.

Similarly, If we use channel-group 1 time slots 6-10, we are telling R2 to use timeslots 6 -10 for sending and receiving data.

Is my understanding correct?

You have a great day!

[Giuseppe Larosa · Accepted solution]

Hello Sarah,

your understanding is correct is not enough to use the same number of timeslots the two endpoints have to agree on what timeslots they use for sending and receiving traffic

Have a nice week

Hope to help

Giuseppe

[sarahr202]

Thanks Giuseppe