METHOD FOR MAINTAINING SIP CALLS IN THE EVENT OF HARDWARE FAILURE OF REDUNDANT IP SYSTEMS

摘要

The prior art cannot satisfy the increased demands imposed on the protection of an SIP call, since the data which are relevant to the call and are dynamically handled as standard during call set-up have to be restored again in the event of failure of a device which is used to route the call so that said call is not lost. The reason for this is that the data which are known as SDP (Session Description Protocol) data and relate to the terminal point are not present in the redundant device, which is switched to stand-by in the event of a fault. The invention solves this problem by taking the data which relate to the terminal point from an adjacent node, where said data are stored, using protocol-related messages when changing over to the redundant device and by transmitting said data to the redundant device.