Hello Everyone.
Do you know which parameter configures the call time in IMS?
In our current scenario VoLTE calls are droping after 30 minutes.
1 Like
What is the cause in bye?
Is it rtp inactivity?
If yes we need to increase rtp inactivity time.
RTP inactivity timer is usually 20 seconds, no way to have it 30 minutes…
1 Like
I’m trying to simulate this scenario now to take some traces, but it doesn’t seem to be related to RPT.
I’m mean, the customer who informed us about this situation has tested several times, and he was talking the whole call, but in all attempts the call dropped in exactly 30 minutes.
It seems to be some IMS parametrization.
You need to know the reason on the bye.
Do a capture.
There is such timer in TAS.
Is TAS probably sending the bye with a cause stating something?
Default value of this timer is 30 minutes.
So can be changed to 1-2 hours as convenient.
What is this TAS?
TAS = Telephony App Server
A Telephony Application Server (TAS) is a SIP user agent that maintains call state and provides basic call processing services. It’s a central function in telco networks that keeps connection status stable using the Session Initiation Protocol (SIP) network protocol.
The bye received came as “Normal Call Clearing”.
I will check the timer in TAS.
Find this timer in the TAS and give it a try.
And please let us know how it went.
I think it’s session timer set at x-CSCF nodes (P/S) or all nodes involving SIP.
I am not sure, you can check with IMS team. It’s default value is 1800s.
It’s a type of handshake mechanism between terminals and networks by periodically using UPDATE messaging.
By setting a session timer, the system can automatically release resources if no activity or handshake messages are detected within a specified period.
You can check if someone has set the timer now or changed to default value.
Yeah, I think this is the problem.
I saw this Session Expire in the invite, and I’m trying to find this configuration in IMS.
Check your features of session border controller.
Some vendors provide session timer as a feature.
I was wondering, does in the trace/pcap you see another invite (re-invite) like to refresh the session-expires in a 200 ok?
And if the 200 ok indeed arrived, take a look at the rtp port to see if it’s changed from the initial rtp port.
Name of this parameter is Long Call Duration.
This one is session timer.
Both can cause the drop.
First please clarify if BYE is generated by TAS or x-cscf.
And also from MO or MT leg.
Than we can comment more accurate.
Normally this is due to maximum time duration or long time duration that is set in TAS, this timer determine the maximum duration of call, after that the network release the call, in Nokia TAS the parameter is: call-duration-timer
Hey guys, just to update you!
We identified that there are a lot of ways to do this “session expires” through the IMS.
In our scenario, the parameter that was terminating the call was in ISBC.
1 Like
Wooowww, thanks for the share!
So was it a timer?