All I ran into a small problem with our SER server sending calls to a Quintum CRSP or Call Relay Server. Here is what I received back from the Quintum software group. The SIP device is our SER server. The Quintum CRSP is used to take inbound SIP calls and sends them out as H323 calls to a terminating PSTN gateway. SIP device makes call #1 to CRSP Call #1 gets alerting from H323 The same SIP device makes call #2 with same SIP call-ID, same ANI, Same DNIS Call #2 Fails CRSP frees the call #1 since it has the same call id Call #1 receives connect from H323 side System hangs They are in the process of changing their software to accommodate this SER issue but have advised me to contact the makers of the SIP device and let them know they are not following the SIP standard. I believe the SER is send a second "INVITE" because the CRSP didn't reply fast enough, or it is sending a re-"INVITE" after an "INVITE" timeout, which could be my bad. Rick T