SMS/Messaging not working upon UE reattach

[somasekhar251]

Hi,
We are seeing a problem in the SMSC where one UE loses the ability to send messages after a cycle of deregistration and re-registration. Here's the sequence:

1. Deregister UE-A.
2. Send 3-4 messages to UE-A (while it's offline).
3. Re-register UE-A.
4. Now, when UE-A and UE-B try to message each other, UE-B cannot send.

I have already referred to the issue here: (#558), but our problem seems somewhat different.

message_not_forwarding.zip

Thanks & regards.

[herlesupreeth]

@somasekhar251 I noticed 2 things:

1. I think you are not using the latest commits from this repo or have not recompiled the base image of kamailio - Because I see SIP NOTIFY sent upon UE de-registration is not right towards both SMSC and UE
2. I see that S-CSCF is not publishing information about reg events to its subscribers (e.g. SMSC) as a result SMSC was not able to forward the SMS

I have now fixed the problem in point 2 by making SMSC always request reg information from SCSCF whenever it wants to forward the SMS to the destined UE. So please pull the latest commits from master branch and give it a try.

Please also note that if you send a SMS to a UE which is offline there is a high chance that it wont be delivered to that UE because there is no store and forward when online mechanism. There is a chance it will be delivered only if offline UE registers back within 6 seconds I think (2 * SMS retry every 3 seconds)