IN STRICTEST CONFIDENCE
BT Wholesale
Issue 1: 2012© British Telecommunications plc
Page 32 of 33
IN STRICTEST CONFIDENCE
9.3
Outbound Calls Fail
Check that the Device is registered as above.
Check that the SIP/RTP ports are not being blocked by a firewall on the network. Details of the
ports can be found in the Security Guide under Support Centre
»
Downloads
»
General Help &
Information.
Check whether any calls can be made between extensions on the PBX; if not they the issue is
likely to be local to the PBX.
Check that the device is sending out SIP messaging for calls by taking a SIP Protocol Trace and
looking for outbound INVITES within this.
Check that the INVITE’s are not being continually challenged by the Registrar with 401
responses; if they are then check the SIP Networking Authentication Information details are
the same as those set in the Business Portal.
Check that the expected outbound CLI of either the Trunk Group or the Trunk User is being
presented in either the From or the P-Asserted-Identity in the outbound SIP INVITE.
If the Trunk Group or Trunk User DDI’s are being sent out in the INVITE make sure that they are
in the correct format i.e. 441234567890.
If none of the above points highlight the cause please take a SIP trace of a call failing where
possible and raise a ticket with Support.