Cell Relay Archive

[Chris_Martin <chm@netedge.com>]

Santosh S wrote:
> 
> Hello,
> 
> The IMA specs talks about an ID (IMA ID) assigned for a group. I am
> confused why the ID is required. Are there several groups between a set of

The IMA ID identifies the group.  This number is passed in ICP cells.

> near end and far end IMA units, each with a different set of Links

There could be. Muxes will collect data from IMA groups and multiplex
the data stream (of IMA cells) into higher rate (DS3, OC3) backbone
networks.  Several edge devices could be deployed in a carrier network
to collect traffic that feeds into a central backbone switch.

> associated with it ?  I don't think this is the case. Then is it that, the 

Why wouldn't this be the case?  Multiplexing lower rate NxT1 rate "UNIs"
(or T1 UNIs for that matter) seems like a rational thing to do. 

> group refers to a unit (i.e each IMA unit is identified as a group. So in
> a multi port switch if each port has an IMA unit, the IMA IDs correspond
> to the ports). I may be totally wrong in my interpretation.
> 
If a "unit" represents an access device, and the device was configured
with IMA links in a single IMA group, then the IMA ID could be used as a
way to identify the "units."  If you substitute the word "port" with
"IMA group" in the last 3 cases in your post, then I think you are right
on track.

Keep in mind that the "port" (in the IMA context as you have used it) on
a IMA-enabled switch does not correspond to the physical (T1/E1) ports,
but a collection of ports.  

> Can anyone clarify the above point.
> 
I hope this helps.

> Thanks.
> 
> Santosh
> 
> ...........................................................
> He that would govern others should first be the master of himself
> ...........................................................
> 
> Santosh S.
> 
> Phone  -       +91-080-5588422 extn-563
> e-mail -       santosh@wipinfo.soft.net
> ...........................................................

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Chris Martin         martin@NetEdge.com        http://www.netedge.com
NetEdge Systems      PHONE: (919) 991-9253     FAX: (919) 991-9160
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