Communication system and method

A computer program product for operating a modem for use at a terminal, the modem having a processing apparatus, a first interface apparatus comprising a first wireless transceiver for connecting to a wireless cellular network, and a second interface apparatus for connecting to the terminal;

• wherein the computer program product comprises code embodied on a non-transitory computer-readable medium and configured so as when executed on the processing apparatus of said modem to:
• transmit a first request message to a part of the wireless cellular network to request establishment of a channel to access a further, packet-based network via the first interface apparatus, wherein the first request message requests said as being of a type that supports both a first and second version of a packet protocol;
• wherein the processing apparatus is configured to receive a first response message via the first interface apparatus, the first response message indicating rejection of the first request, and the code is configured so as when executed to, upon detecting that a field in the first response message defines a reason other than said part of the wireless cellular network does not support first and second versions of the packet protocol on a single channel, transmit a default request message to said part of the wireless cellular network to request establishment of a channel to access the further, packet-based network via the first interface apparatus, wherein the default request message requests said channel as being of a type that supports the first version of the packet protocol.

A method of operating a modem at a terminal, the modem having a first interface apparatus comprising a first wireless transceiver for connecting to a wireless cellular network, a second interface apparatus for connecting to the terminal, wherein the method comprises:

• transmitting a first request message to a part of the wireless cellular network to request establishment of a channel to access a further, packet-based network via the first interface apparatus, wherein the first request message requests said as being of a type that supports both a first and second version of a packet protocol;
• receiving a first response message via the first interface apparatus, the first response message indicating rejection of the first request, and
• upon detecting that a field in the first response message defines a reason other than said part of the wireless cellular network does not support first and second versions of the packet protocol on a single channel, the method further comprising:
• transmitting a default request message to said part of the wireless cellular network to request establishment of a channel to access the further, packet-based network via the first interface apparatus, wherein the default request message requests said channel as being of a type that supports the first version of the packet protocol.

A system comprising:

• a terminal;
• a wireless cellular network;
• and
• a modem for use at the terminal, the modem comprising:
• first interface apparatus comprising a first wireless transceiver arranged to connect to a wireless cellular network;
• second interface apparatus arranged to connect to the terminal;
• and
• processing apparatus arranged to transmit a first request message to a part of the wireless cellular network to request establishment of a channel to access a further, packet-based network via the first interface apparatus, wherein the first request message requests said channel as being of a type that supports both a first and second version of a packet protocol;
• wherein the processing apparatus is further arranged to receive a first response message via the first interface apparatus, the first response message indicating rejection of the first request,
• wherein the processing apparatus is further arranged, upon detecting that a field in the first response message defines a reason other than said part of the wireless cellular network does not support first and second versions of the packet protocol on a single channel, to default to transmit a default request message to said part of the wireless cellular network to request establishment of a channel to access the further, packet-based network via the first interface apparatus, wherein the default request message requests said channel as being of a type that supports the first version of the packet protocol.