摘要 |
<p>An originating P-CSCF node receives a SIP INVITE request from first user equipment (UE) that originates a call to a second UE. If a relay candidate address for the first UE is not present in the SIP INVITE request, the SIP INVITE request is modified to include a first address provided by an originating IMS-AGW node as a relay candidate for the first UE and forwarded to the second UE. The originating P-CSDF node receives a SIP INVITE response message from the second UE in response to the SIP INVITE request. If a relay candidate address for the second UE is not present in the SIP INVITE response, the SIP invite response is modified to include a second address provided by an originating IMS-AGW node as a relay candidate for the second UE and forwarded t the first UE. The address information is used by both UEs in ICE operations.</p> |