In Unified Communications Managed API version 1.0, an endpoint can send messages to another endpoint without establishing a signaling session. Such an operation is referred to as page-mode messaging. In page mode, a message is delivered from the source to the target without a handshake being required between the two endpoints. Unified Communications Managed API version 1.0 exposes the SendMessage (or BeginSendMessage … EndSendMessage) method to support page-mode messaging.
The recipient of a page-mode message must subscribe to the MessageReceived event in order to receive this type of message.
For information about the programming pattern for sending and receiving page-mode messages, see Sending and Receiving Page-Mode Messages.