Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

how many B channel is up?

"When the ISDN call has been established, one B channel will be up and the other one will be shown as down" How it works? Why don't both channel up? If they won't come up at the same time, when will the second B channel up?

2 REPLIES

Re: how many B channel is up?

Hi

Second B-Channel will only come up based on the load conditions or if you have configured it to do so.

Either you should have configured dialer threshold value to bring the second interface in addition to multilink command or ppp multilinks maximum command.

regds

New Member

Re: how many B channel is up?

The most common cause would be:

1. You only purchased 1 BRI channel from your provider

2. Your provider configured their end to use different numbers on the two B channels

3. You didn't configure bundling of two ISDN channels

Root cause of your problem could be one or more of the above.

To configure bundling of ISDN channels, configure the following on your Dialer or BRI interface:

encapsulation ppp

ppp multilink

ppp dialer-threshold 1 either

WARNING: the bundling of ISDN channels can only work if you purchased two ISDN channels from your provider. If you only purchased a single channel, configuring multilink can cause the second channel to flap every second, which in turn can cost you BUCKET LOADS of cash!

HTH

191
Views
4
Helpful
2
Replies
CreatePlease login to create content