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ISDN BRI Phone Line with Different Phone Numbers ???

Hi anyone please clarify my below doubts;

I have two remote sites, each connected back to HQ router with ISDN BRI line.

At my HQ router, I have two BRI ports with two different ISDN lines to cater for the two remote sites. If I have one ISDN line with two phone numbers at HQ, can I use it to replace the two existing different ISDN lines so that each remote site can diual different number of that ISDN line ?

If yes, in term of BRI Channel and Bandwidth allocated, one ISDN BRI line with two phone numbers and the two ISDN BRI phone lines, are they the same ?

Please help to confirm.

3 REPLIES

Re: ISDN BRI Phone Line with Different Phone Numbers ???

ISDN provides 128 kbps bandwidth on one BRI port. It has 2 channels each 64 kbps each. So for the same BRI port, you can have two phone numbers. Each call will get 64 kbps bandwidth. So if you use a single BRI port at the HQ, and each remote site dials into it, each site will get 64k. If you use two BRI cards at HQ, you can configure dialer profiles at the remote sites, and make each of the remote sites get 128k.

New Member

Re: ISDN BRI Phone Line with Different Phone Numbers ???

Hi Shanky, .

For one ISDN line, it comes with one NT1 box, there are two S/T ports, each can connect to an ISDN device, so each S/T port can give max how much bandwidth (64K / 128K) ?

If physically I connect only one S/T port to my router BRI port, so how can I configure my router to enjoy the 128 K bandwidth ?

In yr last answer, you said by playing around with the dialer profiles at remote sites, I can gain 128K, is that meant the 2nd B-Channel of ISDN line at the remote being triggered ?

Is it using "load-threshold" ? Please clarify how to do it .

Thank you so much.

Please help.

Re: ISDN BRI Phone Line with Different Phone Numbers ???

For every single ISDN line, you will get 128 kbps bandwidth, if you place 2 calls, each 64k each. Since you have 2 S/T ports on the NT 1 box, If you connect two ISDN devices one each to each port, both devices will share the 128 kbps bandwidth.

If you physically connect only one S/T port to your router BRI port, to get 128 k bandwidth, you can play around with Dialer Load-threshold command

YOu can set the load threshold to 50 percent (128) so that when the traffic on B1 channel reaches 50 percent, second call is placed. If you want both BRI channels to come up as soon as the ISDN Link comes up, you can set load threshold to 1.

ALso you might want to additionally configure ppp multilink on the ISDN interface of the router.

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