Active sessions and dialogs may be moved between connections and P-CSCFs.
For example, in some embodiments either new bindings may be created with
a different connection for a Public User ID or the UE may re-register one
or more specific bindings for a Public User ID from one connection to
another. The capabilities improve service continuity when handing over
between IP-CANs. FIG. 13 illustrates exemplary messaging for moving
bindings to a new connection for a Private User ID between UE (1305) and
P-CSCF (1307) when the UE (1305) is in a visited IP-CAN, that is, visited
network (1303). The UE (1305) invokes the unprotected global seamless
re-registration of the embodiments via an unprotected initial
registration procedure wherein the UE (1305) includes a "seamless-ims"
parameter in the Require and Proxy-Require headers of the REGISTER
request (1313). The S-CSCF (1311) provides the capability to subsequently
re-register bindings over new or existing connections.