Session initiating method and system

Disclosed are a session initiating method and system, comprising: a calling terminal transmits a call request message to a service server, and the service server transmits a call notification message to a push server according to the call request message; after receiving the call notification message transmitted by the push server, a called terminal establishes a network connection to the service server, and obtains the call request message. The present invention can initiate a session without the called terminal being online.