[Asterisk-Users] SIP: missing "180 ringing"

[Thilo Salmon]

Did any of you ever experience missing "180 ringing" messages when
dialing from a sip agent through an asterisk box? I tried both a Zap and
another SIP channel for dialout. Using a ISDN zap channel the call setup
would look like

SIP-UA       *          PSTN

  |          |            |
  |INVITE->>>|            |
  |          |            |
  |<<<-Trying|            |
  |          |            |
  |          |SETUP->>>>>>|
  |          |            |
  |<-Sess Prog            |
  |          |            |
  |          |<<-SETUP ACK|
  |          |            |
  |          |<<-CALL PROC|
  |          |            |
  |          |<<-ALERTING |
  |          |            |
  |          |<<-CONNECT  |
  |          |            |
  |          |CONNECT ACK>|
  |          |            |
  |<<<-200 OK|            |
  |          |            |        

I would expect the incoming ALERTING message to trigger a 180 ringing
message on the sip side. Some user agents appear to not indicate
"Ringing" to the caller unless the see this message. So it would be very
desirable to have those.

This behaviour occurs with 0.7.2, the lastest stable and the last weeks
unstable checkout. Has anybody seen this before?

Thilo