Channel Groups in multiple data T1 multilink PPP

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Oct 20th, 2008
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3725 with 12.3(7)T and VWIC-2MFT-T1. Two T1 lines set up in multilink ppp configuration to aggregate bandwidth. Controller T1 0/0 set up with channel-group 0 and controller T1 0/1 set up with channel-group 1. I am confused about channel-group config when both T1 lines aggregated. Should I use the same channel-group and why? or, why not? We are not splitting channels between different uses) Will using one group decrease the aggregated bandwidth total? (As I said, I don't understand channel groups that well, except I get splitting channels when used for different purposes (e.g. some to data and some to voice).

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Richard Burts Mon, 10/20/2008 - 10:46
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In the situation that you describe I do not believe that it makes much difference whether you use the same channel-group identifier or use different ones. Especially if you are putting all channels into a single channel group then the main impact that I am aware of about the channel group identifier is what numeral goes into the serial interface identifier. If both T1s use channel group 0 then you would get serial interfaces like:



and if you use different channel group identifiers you would get something like:



The choice of channel group identifiers has no impact on aggregated bandwidth.




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