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DDR: Trying to bypass an ADSL’s restriction of my local loop.

Unanswered Question
Jun 4th, 2003
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I have connected a BRI and ADSL link’s into a CISCO 1721-ADSL. The ATM’s PVC over ADSL has a restriction of SCR=10% of PCR… As soon as ATM get congested I would like to add some B-channels of ISDN link. (BRI). Normally, I can add Bw, when my output queue at some point of use, in both way ó either. But did not find how to make the router react under network congestion.

I will appreciate any advice. Thks

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tepatel Thu, 06/05/2003 - 08:20
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You need to use "backup interface bri" command with "backup load " command under the atm interface. so that if the load on atm interface is beyond the configured threshold, bri line will be activated and load will be shared.

Now with that make sure that bri and atm line is terminated on the other side on the same equipment as well just like you have both the lines on the same 1721. Otherwise it will not work. Visit following link for backup config


Just add "backup load .." as described below


Eduardo Terrades Fri, 06/06/2003 - 00:19
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Thks, for your answer, but not pretty sure to understood.

I as long as I understood “backup-load” triggers the BRI, when the output queue of the router gets close to the “fixed” threshold value. It is a very useful command when I want to get more Bw available to Tx more packets away. But in my case, I want to bypass a “temporal” network congestion issue, the ATM-Broadband Network (where the ADSL local-loop is connected, PVC is a VBR-nrt) which has, under severe congestion, only the guaranty 10% of Bw (SCR). The most of the time (99,5% of the cases), I will have 85% of Bw available. If I set-up the threshold value, at the low value 10%, it will be a inefficient and expensive use of ISDN…

So, I suppose that the router will not be aware of that situation (network congestion) and it will still sending the packets over the ADSL loop, no matter if there a need of few ó lot of packets.


tepatel Fri, 06/06/2003 - 08:07
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Yeah..i got your point now..I don't think of any way to trigger the isdn to dialout in the event of temp. congestion.


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