24 Mar
2022
24 Mar
'22
3:38 p.m.
Hi everyone,
I'm facing the following situation.
Clients are connected over TLS. Therefore there is no retransmission in
Kamailio.
How can I prevent this call drop?
+---+ +-----------+ +-----+
+-----+
| A | | Kamailio | | B1 |
| B2 |
+---+ +-----------+ +-----+
+-----+
| | |
|
| INVITE | |
|
|------------------------------------>| |
|
| | -------------------\ |
|
| |-| Parallel forking | |
|
| | |------------------| |
|
| | |
|
| | INVITE |
|
| |---------------------->|
|
| | |
|
| | INVITE |
|
|
|--------------------------------------------------->|
| | |
|
| | 180 Ringing |
|
| |<----------------------|
|
| | |
|
| | |
180 Ringing |
|
|<---------------------------------------------------|
| | |
------------------------\ |
| | |-| User
answers the call | |
| | |
|-----------------------| |
| | |
|
| | 200 OK |
|
| |<----------------------|
|
| | |
|
| 200 OK | |
|
|<------------------------------------| |
|
| | |
|
| ACK | |
|
|------------------------------------>| |
|
| | |
|
| | ACK |
|
| |---------------------->|
|
| ------------------------------\ | |
|
|-| Session established with B1 | | |
|
| |-----------------------------| | |
|
| | |
| ----------------------------\
| | |
|-| Client changes network |
| | |
| | LTE to Wifi or vice versa |
| | |
| | Temporary connection lost |
| | CANCEL |
| |---------------------------|
|
|----------------------------------------------X |
| | |
| -------------------------------------------------\
| | |
|-| Reconnected with different IP |
| | |
| | CANCEL is missed and client continues ringing. |
| | |
| | User answers the call. |
| | |
200 OK | |------------------------------------------------|
|
|<---------------------------------------------------|
| | |
|
| 200 OK | |
|
|<------------------------------------| |
|
| | |
|
| | |
BYE |
|
|<---------------------------------------------------|
| | |
|
| BYE | |
|
|<------------------------------------| |
|
| ---------------------------\ | |
|
|-| Session terminated by B2 | | |
|
| | Call Drop | | |
|
| |--------------------------| | |
|