Hi all,
I'm facing an odd issue where if an external phone calls an internal phone, I can tell that the internal phone start ringing 2secs before the mobile phone hear the ringing tone, causing the internal user to pick up the call right away and not hearing anything for about 1-2secs. If the user waits 3-4secs prior to pick up the call everything work fine. In this current situation I believe the delay is introduced by the original IPTSP forwarding the DIDs to our IPTSP as if I call the same internal phone from the same external phone but directly to our IPTSP DID the delay is drastically reduced.
I have already put in place the SIP early offer on the CUCM trunk to our SBC but this does not seem to prevent the delay.
Have you ever experienced a similar issue and do you think there is a way to delay a phone and make it ringing after a certain amount of time?
Thank you!
