iOS "No RTP activity" for voice calls


Hi everyone,

We've been successfully running a couple of apps (iOS and Android) for the last 2-3 years using WCS.

We utilize WCS as a wss-SIP gateway connected to Asterisk. Asterisk forwards outgoing calls to our providers via SIP.

However, over the past month, we've started receiving some complaints from our customers. They mention connecting to calls but experiencing no audio on both incoming and outgoing sides. This results in a timeout due to "No RTP activity," leading to the call being disconnected.

After reviewing information on the Forum, I've tried to clarify a few points regarding our issue:

  • The system works well for Android, and generally for iOS, but all complaints are specifically from iOS users.
  • We replicated the issue with an iOS 15 Pro terminal, version 17.1.1. The problem occurs both with our office Wi-Fi network and with 4G, leading us to rule out network issues, especially since my iPhone 11 with version 17.1.2 works perfectly.
  • The log from the failed instance shows this. I also have a pcap file indicating more than 2 MB of UDP messages between the iOS device and the server, suggesting that the handsets are transmitting media (though I can't confirm this as it's wss and encrypted).
Thanks in advance and best regards.



Additional information: We have upgraded the iPhone 15 to version 1.7.2, but the issue still persists.

Today, we've had more than 50 calls with this problem. :-(

server_logs$ grep "No RTP" flash* | wc -l


Staff member

1. Please make report and submit using this form
If server build is too old (what is version?), please provide SSH access through the same form.
2. Please provide pcap dump of SIP call between WCS and Asterisk, plus corresponding logs.
3. Try to build the minimal app
And let us know if issue is reproduced with the built app.
4. If issue is reproduced with this minimal app, please provide SIP credentials (one SIP account) and IVR callee number.
We will connect to your WCS server and make the call for debug.


Thanks a lot for your quick answer.
Before doing all the report process we have upgrade the beta version of one app to the release 2.6.120 and now we don't reproduce the issue.
We are testing it in more detail to be sure that it fixs the issue. We'll keep you informed

Thanks again