So here's a weird one. I've already found a workaround for it, but I don't understand WHY it's necessary or what is going on. (At the very least, even if I don't get an answer, I hope this might help someone else who is struggling with the same or a similar issue.)
As I've written before, we're transitioning an MICS 0x32 cabinet from 15 analog DS-loop trunks from the LEC to T1 (non-PRI, E&M + DID). Actually, we're migrating over to a VoIP trunk, and using T1 to interface the MICS with the VoIP trunk (using Asterisk + an Asterisk T1 interface card).
Incoming calls work great...DID and all. No problems so far.
For outgoing, I put all T1 trunk lines in a common line pool, pointed a route at that pool, and assigned a dest code to that route. What's happening is that if I pick up an Intercom line and dial that dest code, if I have Asterisk generate a dial-tone, I'll hear dial-tone for about 1 second after dialing the dest code, and then the phone will suddenly drop the call and display "Line in use". If I turn off dial-tone generation on Asterisk, the Norstar behaves appropriately.
After some trial-and-error, I discovered that if I introduce a brief delay before Asterisk begins generating dial-tone after the line is seized by the Norstar, then the Norstar won't think the line it just tried to grab is in use (100ms seems to be enough time).
It's almost like the Norstar hears "noise" on the line the second it goes off-hook and doesn't recognize it to be dial-tone noise, so it assumes the line must be in use. By introducing a brief delay, it now hears silence when it first goes off-hook and so doesn't freak out. I wonder if it could simply be a bug...the MICS is still on 4.1 s/w.
Any ideas? The 100ms delay is no big deal and really not noticeable. But I just thought it strange, esp. since I haven't run into anybody else who has documented similar behavior with MICS and non-PRI T1.
Thanks,
-- Nathan
As I've written before, we're transitioning an MICS 0x32 cabinet from 15 analog DS-loop trunks from the LEC to T1 (non-PRI, E&M + DID). Actually, we're migrating over to a VoIP trunk, and using T1 to interface the MICS with the VoIP trunk (using Asterisk + an Asterisk T1 interface card).
Incoming calls work great...DID and all. No problems so far.
For outgoing, I put all T1 trunk lines in a common line pool, pointed a route at that pool, and assigned a dest code to that route. What's happening is that if I pick up an Intercom line and dial that dest code, if I have Asterisk generate a dial-tone, I'll hear dial-tone for about 1 second after dialing the dest code, and then the phone will suddenly drop the call and display "Line in use". If I turn off dial-tone generation on Asterisk, the Norstar behaves appropriately.
After some trial-and-error, I discovered that if I introduce a brief delay before Asterisk begins generating dial-tone after the line is seized by the Norstar, then the Norstar won't think the line it just tried to grab is in use (100ms seems to be enough time).
It's almost like the Norstar hears "noise" on the line the second it goes off-hook and doesn't recognize it to be dial-tone noise, so it assumes the line must be in use. By introducing a brief delay, it now hears silence when it first goes off-hook and so doesn't freak out. I wonder if it could simply be a bug...the MICS is still on 4.1 s/w.
Any ideas? The 100ms delay is no big deal and really not noticeable. But I just thought it strange, esp. since I haven't run into anybody else who has documented similar behavior with MICS and non-PRI T1.
Thanks,
-- Nathan
