1. A method for re-assigning Serving Call Session Control Function (S-CSCF) services to a user of a Home Subscriber Server (HSS), in a telecommunications network, the method comprising: i) assigning a first S-CSCF to the user during an internet protocol multimedia subsystem (IMS) registration procedure; ii) uploading dynamic registration information from the first S-CSCF to the HSS during the IMS registration procedure, wherein the dynamic registration information comprises information created during the IMS registration procedure; iii) storing the dynamic registration information in the HSS; and iv) downloading the stored dynamic registration information from the HSS to a second S-CSCF during a S-CSCF re-assignment procedure for the user; wherein the dynamic registration information comprises at least one of a binding address, a binding duration, a path header value, Expires header, Contact header.