No Ringback on SIP calls

You may have ringback for some calls, but not others. The difference in the SIP signaling is that you may find that the carrier might be sending a 183 PROGRESS, rather than a 180 ringing. For the SBC to allow the ringback to come from the carrier, then we need to make sure the Audiocodes SBC is set to support PRACK.

  1. Login to the Audiocodes
  2. Set your view to advanced
  3. Expand SIP Definitions > Click General Parameters
  4. Set PRACK Mode to “Supported”
  5. Click Apply
  6. Click Burn
  7. Expand Coders and Profiles
  8. Click the Carrier/ ITSP
  9. Change PRACK mode to Optional