E1 match/mapping Serial interface

[jaspreetw]

I have Observed that normally we have E1 a/b/c matched to Serial interface like serial4/a/b,I have a cofusion that how and why this is done, if we have E1 card on router we can do straight away..

[jackyoung]

Normally, it depends on the router model to have different presentation of module no. In you example.

Serial a/b/c = slot a, module b, port c in Cisco 7xxx. Sometimes one module can support two mini-module, so the 'b' will be the mini-module no.

The 'a' is the slot no. in each device.

If it is a 36xx. It may looks like serial a/c = slot a, port c.

Hope this helps.

[jaspreetw]

thanx jack, but how serial interface is mapped/matched to the E1 controller.

Like Router A E1 1/0/6 -- SERIAL1/0/6:0

and why is it necessary if we have E1 card.

[tdrais]

I suspect you are talking about the controler configuration and the serial configuration.

This varies a little depending on the type of interface card.

Some cards have the ability to break the circuit into multiple serial interfaces. You can map the individual channels to differrent serial logical serial ports.

control e1 x/x/x

channel group 0 timeslots 1-5

channel group 1 timeslots 6-10

....

Serial x/x/x:0

serial x/x/x:1

When you are mapping all the channels to serial interface or when your card does not support mapping to multiple channel groups it does not appear to make much sense. I suspect it is for consitancey of configuration more than anything else.

[jackyoung]

I beleive it is a multichannel interface (e.g. channelized E1 / PRI), the no. behind : is the channel no.

Check below for info. and sample config.

http://www.cisco.com/univercd/cc/td/doc/product/core/7206/7206cfig/3281chan/index.htm

Hope this helps.