Multimedia communications in a telecommunications network

1. A communications network configuration for delivery of multimedia services to terminal devices, said communications network configuration comprising a packet network to which a plurality of terminal devices are connected, a service provider network for providing multimedia services to said terminal devices, a virtual circuit switched network provided intermediate said packet and service provider networks, and a gateway distributed over said virtual circuit switched network comprising a client application unit interfacing said virtual circuit switched network to said packet network and a virtual channel interface unit interfacing said virtual circuit switched network to said service provider network, wherein said client application unit is configured to bind one or more logical channels for a multimedia call requested by one of said terminal devices to association tags for respective virtual channels of said virtual circuit switched network and to forward said association tags to said virtual channel interfacing unit, and said virtual channel interfacing unit is configured to assign to said multimedia call one or more virtual channels associated with said association tags and to inform the client application unit of channel numbers for said one or more assigned virtual channels to thereby complete set up of the multimedia call.

2. The network configuration as claimed in claim 1 , wherein said virtual circuit switched network comprises an asynchronous transfer mode (ATM) network.

3. The network configuration as claimed in claim 2 , wherein said ATM network is adapted to carry traffic in AAL-2 minicells.

4. The network configuration as claimed in claim 2 , wherein said virtual channel interfacing unit comprises an AAL-2 interface unit.

5. The network configuration as claimed in claim 4 , wherein said distributed gateway further incorporates a telephony service manager for establishing calls between said terminal devices and said service provider network.

6. A method of transmitting service traffic in a communications network for delivery of multimedia services to terminal devices, said communications network comprising a packet network to which a plurality of terminal devices are connected, a service provider network for providing multimedia services to said terminal devices, and a virtual circuit switched network provided intermediate said packet and service provider networks, the method comprising:

transmitting said multimedia service traffic via a gateway distributed over said virtual circuit switched network, said gateway comprising a client application unit interfacing said virtual circuit switched network to said packet network and a virtual channel interface unit interfacing said virtual circuit switched network to said service provider network;

at said client application unit, binding one or more logical channels for a multimedia call requested by one of said terminal devices to association tags for respective virtual channels of said virtual circuit switched network and forwarding said association tags to said virtual channel interfacing unit; and

at said virtual channel interfacing unit, assigning to said multimedia call one or more virtual channels associated with said association tags and informing the client application unit of channel numbers for said one or more assigned virtual channels to thereby complete set up of the multimedia call.

7. A distributed gateway for a communications network configuration for delivery of multimedia services to terminal devices, said communications network configuration comprising a packet network to which a plurality of terminal devices are connected, a service provider network for providing multimedia services to said terminal devices, and a virtual circuit switched network provided intermediate said packet and service provider networks, said distributed gateway being distributed over said virtual circuit switched network and comprising a client application unit interfacing said virtual circuit switched network to said packet network and a virtual channel interface unit interfacing said virtual circuit switched network to said service provider network, wherein said client application unit is configured to bind one or more logical channels for a multimedia call requested by one of said terminal devices to association tags for respective virtual channels of said virtual circuit switched network and to forward said association tags to said virtual channel interfacing unit, and said virtual channel interfacing unit is configured to assign to said multimedia call one or more virtual channels associated with said association tags and to inform the client application unit of channel numbers for said one or more assigned virtual channels to thereby complete set up of the multimedia call.

8. distributed gateway as claimed in claim 7 , and further incorporating a telephony service manager for establishing calls between said terminal devices and said service provider network.