<div dir="ltr">Hi everyone,<br><br>I'm facing the following situation.<div><br>Clients are connected over TLS. Therefore there is no retransmission in Kamailio.<br><br>How can I prevent this call drop?<br><br><br><font face="monospace"><br>+---+                             +-----------+              +-----+                      +-----+<br>| A |                             | Kamailio  |              | B1  |                      | B2  |<br>+---+                             +-----------+              +-----+                      +-----+<br>  |                                     |                       |                            |<br>  | INVITE                              |                       |                            |<br>  |------------------------------------>|                       |                            |<br>  |                                     | -------------------\  |                            |<br>  |                                     |-| Parallel forking |  |                            |<br>  |                                     | |------------------|  |                            |<br>  |                                     |                       |                            |<br>  |                                     | INVITE                |                            |<br>  |                                     |---------------------->|                            |<br>  |                                     |                       |                            |<br>  |                                     | INVITE                |                            |<br>  |                                     |--------------------------------------------------->|<br>  |                                     |                       |                            |<br>  |                                     |           180 Ringing |                            |<br>  |                                     |<----------------------|                            |<br>  |                                     |                       |                            |<br>  |                                     |                       |                180 Ringing |<br>  |                                     |<---------------------------------------------------|<br>  |                                     |                       | ------------------------\  |<br>  |                                     |                       |-| User answers the call |  |<br>  |                                     |                       | |-----------------------|  |<br>  |                                     |                       |                            |<br>  |                                     |                200 OK |                            |<br>  |                                     |<----------------------|                            |<br>  |                                     |                       |                            |<br>  |                              200 OK |                       |                            |<br>  |<------------------------------------|                       |                            |<br>  |                                     |                       |                            |<br>  | ACK                                 |                       |                            |<br>  |------------------------------------>|                       |                            |<br>  |                                     |                       |                            |<br>  |                                     | ACK                   |                            |<br>  |                                     |---------------------->|                            |<br>  | ------------------------------\     |                       |                            |<br>  |-| Session established with B1 |     |                       |                            |<br>  | |-----------------------------|     |                       |                            |<br>  |                                     |                       |                            | ----------------------------\<br>  |                                     |                       |                            |-| Client changes network    |<br>  |                                     |                       |                            | | LTE to Wifi or vice versa |<br>  |                                     |                       |                            | | Temporary connection lost |<br>  |                                     | CANCEL                |                            | |---------------------------|<br>  |                                     |----------------------------------------------X     |<br>  |                                     |                       |                            | -------------------------------------------------\<br>  |                                     |                       |                            |-| Reconnected with different IP                  |<br>  |                                     |                       |                            | | CANCEL is missed and client continues ringing. |<br>  |                                     |                       |                            | | User answers the call.                         |<br>  |                                     |                       |                     200 OK | |------------------------------------------------|<br>  |                                     |<---------------------------------------------------|<br>  |                                     |                       |                            |<br>  |                              200 OK |                       |                            |<br>  |<------------------------------------|                       |                            |<br>  |                                     |                       |                            |<br>  |                                     |                       |                        BYE |<br>  |                                     |<---------------------------------------------------|<br>  |                                     |                       |                            |<br>  |                                 BYE |                       |                            |<br>  |<------------------------------------|                       |                            |<br>  | ---------------------------\        |                       |                            |<br>  |-| Session terminated by B2 |        |                       |                            |<br>  | | Call Drop                |        |                       |                            |<br>  | |--------------------------|        |                       |                            |</font><br></div></div>