IMS inbound roamer and short number dialing

摘要

Network nodes for an access network and a home network of a first UE are described for use when routing an originating call from the first UE in the access network including an IMS network. A network node receives a SIP INVITE message associated with the originating call from the first UE, and including a called party number associated with the call. The network node determines whether the first UE is visiting the access network and whether the called party number is associated with the access network. The network node determines whether the called party number is allowable in the access network. The network node modifies and transmits the received SIP INVITE message towards a home network of the first UE to cause the home network to route the originating call to the access network.