Hi experts.

I am using FS for transcoding a call between an iPhone (AMR codec used) to a Cisco 880 Voice simulating PSTN (a legacy phone is connected here).

A call is initiated by iPhone and terminated to the fixed phone; if the B side is silent (VAD enabled), the Cisco 880 stops sending RTP towards FS and, then, FS to iPhone.

After 10sec not receiving RTPs, iPhone drops the call with "Reason: SIP;cause=200;text="RTP Timeout" ".

I tried several options to make the FS not stopping sending RTPs towards iPhone or any other possibility to avoid this issue, but I was not able to get a workaround.

Any idea?

Br. Stefano