A user equipment (UE) attaches to a first access network, intending to access a packet data network (PDN) via a telecommunications system, and is assigned a PDN System Architecture Evolution (SAE) Gateway (GW). The identity of the PDN SAE GW is registered so that, if the UE attaches to another access network, triggering a new attach procedure, the identity is retrieved. A determination is then made whether the previously-assigned PDN SAE GW may be used for the present communications and, if so, it is reassigned. The identity of the PDN SAE GW is registered in an anchor node, which is in a preferred embodiment a Home Subscriber Server (HSS). If the previously-assigned PDN SAE GW cannot be used, or if the PDN SAE GW must be changed, then the communication is reassigned to a new PDN SAE GW.