Handling resources in communications network

A method and apparatus for managing Time Division Multiplex resources for a pool of Mobile Switching Centre Servers in a communications network. Time Division Multiplex resources are arranged at a Media Gateway function serving the pool of Mobile Switching Centre Servers. Virtual Time Division Multiplex resources are allocated to each Mobile Switching Centre Server in the pool and mapped to the Time Division Multiplex resources. An ISUP signalling proxy function may be arranged at the Media Gateway function. TDM resources are allocated to at least one Mobile Switching Centre, and associated with an identifier of the Mobile Switching Centre Server. The TDM resources are mapped to the Time Division Multiplex resource to the identifier. When the media Gateway receives an ISU message, it replaces the identifier with an ISDN User Part signalling proxy function identifier before sending the message to a node in an external network.