Patent ID: 7400881

Claim:
A method, comprising: receiving, at a first call control node, a registration message from a mobile station, said registration message comprising a logical name referring to said mobile station; sending a request to map said logical name to an International Mobile Subscriber Identity referring to said mobile station in a directory; sending a request to update a location of said mobile station to a home location register said request of said first call control node comprising said International Mobile Subscriber Identity; receiving a request to allocate a roaming number from said home location register based on an inquiry message from a second call control node, said inquiry message comprising at least a called party number; forwarding an inquiry response message to said home location register for further transmission to said second call control node comprising at least said roaming number; receiving a call set-up request message comprising at least the called party number from said second call control node in said first call control node; and mapping said called party number to said logical name referring to said mobile station in said directory at a second request of said first call control node, thereby routing calls in a communication system comprising at least one mobile station, the first call control node, the second call control node, the directory and the home location register.