A method and apparatus are described for negotiating “keep-alive” message frequencies of applications running on a wireless transmit/receive unit (WTRU). A node may include a negotiation and synchronization function (NSF) configured to collect information including frequencies of keep-alive messages required by application servers for different applications running on the WTRU, and send a keep-alive message frequency negotiation request message to the application servers to negotiate for a more proper frequency for each application on behalf of the WTRU. The node may further include a buffering and caching function (BCF) configured to cache and buffer application specific attributes including an indication of whether each of the applications needs to send periodic keep-alive messages to an associated application server. The node may be a packet data network gateway, a negotiation and caching gateway, or a serving gateway.