Conversation key distribution method of crossing gate-guard management range under direct route mode

The present invention provides a session key distribution method Gatekeeper across the range of a direct routing mode, the core of: allocating a session key between the calling and called DH negotiation between the master node, the home gatekeeper of the called node. The present invention requires only a main, home gatekeeper of the called node participating in the distribution process the session key, the session key so only the master home gatekeeper of the called node is visible, the message transmission delay is reduced, to avoid the session secret key insecurity in the transmission process, but also the aspect of the present invention is broader scope; thereby achieving the purpose of improving the safety message transmission, message transmission to improve efficiency.