CAS E1 Signalling

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I try to find some information about CAS E1 signalling and how it’s handled by Asterisk. My customer wants to connect to a BT ITS Netrix by CAS E1 E&M. The system is intended to take the channels and mix them
(meetme / confbridge) and send the audio back mixed to each.

The layout:
BT ITS Netrix: CAS E1 E&M <-> MUX – WAN – MUX <-> Digium TE220, Asterisk

I’ve found some documensts describing the Dahdi configuration for CAS
E1, but I have some unanswerd questions:

1. In asterisk can I get the channel-number of the call so I can have different logic for the different channels?

2. How do I handle answer / hangup with CAS? Will DAHDI keep this channels up, or should I query the state of the channels (how?) and bring them up myself if they are down (Dial?)

3. Other suggestions?

CAS is unknown territory for me so I appreciate all the pointers you have. Thank you!

2 thoughts on - CAS E1 Signalling

  • 1. In asterisk can I get the channel-number of the call so I can have Sure, I guess I would just create different incoming contexts for your various channels in chan_dahdi.conf. Or you could write some dialplan foo.

    DAHDI will interpret the CAS signalling and pass those up to userspace as hookstates. All of this should be seamless to you as an Asterisk user. The usual channel Answer() and Hangup() is all that’s needed, just like on any other type of channel.

    Have fun