Operating a network node

A system for use in operating a network node in a telecommunications network,

• wherein the telecommunications network comprises a server responsible for providing telephony services including extension number dialing telephony services to a plurality of end devices,
• wherein the server is located in a first network in the telecommunications network,
• wherein the plurality of end devices comprises at least a first group of end devices located in a second, different network in the telecommunications network,
• wherein the first network is connected to the second network by a communications link,
• wherein the system comprises at least one memory including computer program code;
• and
• at least one processor in data communication with the at least one memory, wherein the at least one processor is configured to, at a network node located in the second network in the telecommunications network:
• monitor signaling messages transmitted between the server and end devices in the at least first group, each monitored signaling message comprising a telephone dialing number for a given end device in the at least first group and an extension number for the given end device;
• on the basis of the monitoring, store mapping data comprising mappings between telephone dialing numbers and extension numbers for end devices in the at least first group;
• and
• in response to detecting a loss of connectivity in the communications link between the first network in the telecommunications network and the second network in the telecommunications network, process extension number dialing request messages received from end devices in the first group according to a detected loss of connectivity operating mode, wherein the detected loss of connectivity operating mode processing is carried out at least in part on the basis of the stored mapping data.

A non-transitory computer-readable storage medium comprising computer-executable instructions which, when executed by a processor, cause a computing device to perform a method of operating a network node in a telecommunications network,

• wherein the telecommunications network comprises a server responsible for providing telephony services including extension number dialing telephony services to a plurality of end devices,
• wherein the server is located in a first network in the telecommunications network,
• wherein the plurality of end devices comprises at least a first group of end devices located in a second, different network in the telecommunications network, and
• wherein the first network is connected to the second network by a communications link,
• the method comprising, at a network node located in the second network in the telecommunications network:
• monitoring signaling messages transmitted between the server and end devices in the at least first group, each monitored signaling message comprising a telephone dialing number for a given end device in the at least first group and an extension number for the given end device;
• on the basis of the monitoring, storing mapping data comprising mappings between telephone dialing numbers and extension numbers for end devices in the at least first group;
• and
• in response to detecting a loss of connectivity in the communications link between the first network in the telecommunications network and the second network in the telecommunications network, processing extension number dialing request messages received from end devices in the first group according to a detected loss of connectivity operating mode, wherein the detected loss of connectivity operating mode processing is carried out at least in part on the basis of the stored mapping data.