[Serusers] SER/Asterisk PSTN Call Transfer Issue.

Hi We have a phone system consisting primarily of SER and Asterisk, and are having trouble transferring inbound calls from the PSTN. We believe the problem is basically that because our phones register with SER, the Asterisk box never sees the call from the original callee to the new callee. i.e. caller --> PSTN --> Asterisk --> SER --> callee's SIP phone callee's SIP phone --> SER --> new callee's SIP phone when the original caller hangs up, the transfer is requested, however Asterisk does not know anything about the second call shown above, and so we see an error about "supervised transfer requested; callid not found". We have found that if, in our SER config, we route 8<extension> through Asterisk, having stripped off the leading '8', and on to the SIP phone via SER, then it works, because Asterisk then 'knows' about the new call, since the second call above becomes callee's SIP phone --> SER --> Asterisk --> SER --> new callee's SIP phone Of course, this is a rather inelegant fix, especially when we actually have more than one PSTN gateway. Does anyone know if there is a more flexible fix, either on the SER or Asterisk side, that might fix our problem? thanks peter -- peter gradwell. gradwell dot com Ltd. http://www.gradwell.com/ -- engineering & hosting services for email, web and voip -- -- http://www.peter.me.uk/ -- http://www.voip.org.uk/ --