It is disclosed a method (and related apparatus) comprising establishing a control session by transmitting and receiving control session-related messages, transmitting restart information indicating a restart of a network element, receiving at least one protocol-related message of a first control session including session-related detail information, transmitting a restoration request message based on the session-related detail information, receiving at least one session parameter necessary for restoring the at least one first session, and restoring the at least one first session based on the received session-related detail information and the at least one session parameter. It is further disclosed a method (and related apparatus) comprising receiving restart information indicating a restart of a network element, processing at least one protocol-related message of a first control session to include session-related detail information, and transmitting at least one session parameter necessary for restoring the at least one first session, and the at least one protocol related message.