A mobile user terminal 402 accesses a packet data network 450 through one or more of several network access points 404-412. One or more control points 432-440 determines which network access point or points the user terminal is to access. Control may be retained in the current control point, or transferred to another control point, whenever it is convenient. There are preferably several routers, each having an associated home agent 418-420 which determines which foreign agents need to be accessed on behalf of each user terminal. There are several foreign agents 422-430, which forward packets received from a user terminal's home agent to the control point currently controlling communications with the user terminal.