3241 ISDN GW backup D-channel using NFAS

[peterson.m]

Hello,

We have 4 ISDN PRI's from ATT provisioned as a trunk group with 1 primary D-channel and 1 backup D-channel.  In the Codian gateway under the port configuration, it only gives the option of Primary or None for D-Channel type.  How can we designate a backup D-channel?  L1/L2 status shows Up on my end, but ATT shows the D channels locked on their side, and I'm getting "parse_q931_header: invalid protocol discrimator" warnings in the log.  All other configurations match up to what they have (type National, NFAS interface ID's, etc.).

Thanks,

Mike

[chmcmaho]

Hi Mike - As we discussed. Postings so that others are aware as well.

Regards - Charlie

Backup D channel for NFAS is not supported at this time. The best you
can do at this time is to have two FAS T1's with each D channel running as
primary.

For example;

Running NFAS without a backup D channel would work. 

Circuit     D-channel     NFAS Group ID     IID
1           Primary       1                 0
2           None          1                 1
3           Primary       2                 0
4           None          2                 1