Kris Boutilier
2004-Oct-06 02:43 UTC
[Asterisk-Users] Can Asterisk provide Answer Supervision signalling to a channel b ank via T1?
I have an older Newbridge Mainstreet 3624 upon which I'm terminating some analog DID lines. They are effectively loop-start trunks with battery supplied by me (ie. FXO) and consumed by the serving central office. One major part of DID is the requirement for providing Answer Supervision in the form of battery polarity reversal on the analog trunks. Without it wierd things start happening, like one way audio, calls torn down by the CO after a timeout period and so on... On my channel bank the reversal relays seem to be controlled by the state of the A bit going across the T1 to the bank - in all other ways they're loop start trunks. Is there a way to get Asterisk to correctly present the Answer state in that bit? I believe what I'm looking for is FXO/DPT (Dial Pulse Terminate). The central office half would be the FXS/DPO (Dial Pulse Originate) side. I've tried Koolstart, but the only time it toggles the A bit is upon disconnect and then only for about half a second. Which seems to be an attempt at open loop disconnect supervision. I think what I'm looking for is a bit progression like this: Tx Rx (relative to channel bank) ABCD ABCD 0000 0101 Both ends on hook 1100 0101 Call starting, near end still on hook 1100 1111 Call connected, both ends off hook ... 0000 1101 Far end hangup, near end still off hook 0000 0101 Call torn down, both ends on hook However, if anyone has a good reference for RBS bit patterns for DPO/DPT perhaps they could post it to the list? Thanks. Kris Boutilier Information Systems Coordinator Sunshine Coast Regional District