Patent ID: 7899043

Claim:
A method for implementing call routing, to be used in a next generation network using soft switch control devices as core control devices, comprising implementing the call routing by route service devices, wherein each route service device is only connected with one or more of the soft switch control devices and one or more of other route service devices, wherein the route service devices and the soft switch control devices are networked in a layered way, wherein implementing the call routing by the route service devices comprises the following steps of: (a) when a route of a user in the next generation network changing, a soft switch control device that the user moves to or moves out of reporting a changed route information related to the user to a route service device at father node of the one of the soft switch control devices, the changed route information including user characteristics information, report node information and route operation type; (b) the route service device that received the reported changed route information looking up a record of the user to be registered from a route information database, and registering a route record of the user to the route information database according to the reported changed route information and content of the record of the user; (c) when a route information of the user reflects a change between the route service device that finished registration and its father node, the route service device that finished the registration broadcasting the route information reflecting the change to the route service device at father node of the route service device that finished the registration; (d) the route service device that received the broadcasted route information registering and broadcasting the received broadcasted route information according to the same method as the route service device that received the reported changed route information; (e) when calling across domains, the soft switch control device to which the calling belongs initiating an inquiry to the route service device at the father node of the soft switch control device to which the calling belongs; (f) the route service device that received a request of the inquiry looking up a route record of the user to be looked up from the route information database, if an inquiring result of the route of the user or an inquiring result indicates that the user does not exist is obtained, performing step (h), otherwise, performing step (g); (g) the route service device that received the request of the inquiry continuing the inquiry to a node in said route record, if there is no route record, continuing an inquiry to its father node, and returning to step (f); and (h) the route service device that received the request of the inquiry returning the inquiring result to the node that initiated the inquiry, any node that receives the inquiring result continuing to return the inquiring result, until returning to the soft switch control device which first initiated the inquiry.