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New Member

Voice Gateway PRI

Hope this is the right forum. We have a 3745 Voice gateway with dual-wic pri's in it and we are adding a 3rd PRI to this box. Is there a way to bond all of them together? Right now I believe we have the 2 pri's going over 1 D channel. Is there a way to add this new pri to this group? Hopefully this makes sense.

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Re: Voice Gateway PRI

I believe this is possible using NFAS. With NFAS you can bind all three PRIs to a single D-channel. However, you may want to consider using a backup D-channel as well.

New Member

Re: Voice Gateway PRI

I don't think we want to go with Nfas. Is there a way I can find out if our PRI's are setup this way?


Re: Voice Gateway PRI

Have you contacted your provider on how the PRIs are configured? If all 3 PRIs are coming from the same provider than they should be able to provide you with the answer.

Re: Voice Gateway PRI

If you have two PRIs using only one D-channel, and all B-channels are always available, you can almost bet that you are using NFAS.

Lookin in your config in the controller section for something like:

controller T1 7/4

framing esf

linecode b8zs

pri-group timeslots 1-24 nfas_d primary nfas_int 0 nfas_group 1

Note the "nfas_d" in the pri-group portion.

If you are trying to conserve B-channels, you can use nfas. However, in terms of bonding, you can achieve similar results by simply hunting across multiple PRIs. Inbound or outbound. The carrier configures the inbound hunt order, and you configure the outbound hunt order by dial-peer preference statements and "isdn bchannel-order" statements under your interface serial x/y:z configuration.

This approach doesn't save B-channels, but it does effectively & functionally "bond" several trunks together.

Let me know if this helps by rating the post.


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