Hey all: I've been thinking through how to handle technology agnostic messaging in ARI. Since Asterisk 10, we've had the ability to send/receive messages in Asterisk (either SIP or XMPP) using the dialplan in a cohesive fashion. Outbound messages are sent using the MessageSend dialplan application/AMI action; inbound messages are handled by a special purpose channel driver (Message) in the dialplan. Various functions (MESSAGE, MESSAGE_DATA) allow for extraction of message information from the received text message. While the existing process works, there's some drawbacks to it. (1) The dialplan is not an ideal place to process a text message. Doing a lot of string manipulations in the dialplan is not much fun. (2) Dispatching the channel servicing the message to a Stasis dialplan application (or to AGI, or any other externally controlled entity) is not ideal, as only a single instance of the channel driver exists to serve all messages. What's more, as a special purpose channel driver, there are many operations that could be executed on a 'normal' channel that would have odd effects on the Message channel. This creates a burden on the consumer of Asterisk to know what is acceptable and what is not. Ideally, we'd have a mechanism in ARI to send messages to SIP/XMPP endpoints/URIs and to be notified over the WebSocket when a message arrives at Asterisk that an application is interested in. This would never hit the dialplan: posting to a REST resource to send a message would get dispatched to the appropriate channel driver immediately; receiving a message would simply send an event out over the WebSocket. This should be possible with only minimal changes in Asterisk's messaging core. I've written a proposal up on the wiki for this here: https://wiki.asterisk.org/wiki/x/ew6wAQ ---- The highlights ---- Allow sending a message to an endpoint through the endpoints resource: POST /endpoints/PJSIP/alice/message { "from": "pjsip:bob", "body": "I am the very model of a major general" "variables": [ { "X-Foo-Bar": "I am a special header" }, { "X-Foo-Yack": "I am not" }, ], } Alternatively, if who you are sending the message to is a bit more arbitrary, simply send it directly to the technology and let the technology sort it out: POST /endpoints/PJSIP/message { "from": "xmpp:bob@xxxxxxxxxx", "to": "pjsip:generic/sip:alice@xxxxxxxxxxxxxxx" "body": "No, *I* am the very model of a major general" } Subscribing to an endpoint subscribes you to messages that are sent to/received from that endpoint: { "type": "MessageReceived", "from": "pjsip:alice", "to": "\"bob\" <bob@my_asterisk_server.org>", "body": "Who's the major general now?", "variables": [ {"SIP_RECVADDR", "127.0.0.1"}, ], } And that's about it. Enabling this functionality is pretty interesting - some SIP providers transform SIP MESSAGE requests into SMS messages; an XMPP chat room could be monitored such that a participant could choose to cause an audio conference to be automatically created and all current participants dialled; applications could use SIP and XMPP to send arbitrary messages to their Asterisk server to control their ARI application. Lots of 'unified communication' possibilities in there. Thoughts & comments appreciated - Matt -- Matthew Jordan Digium, Inc. | Engineering Manager 445 Jan Davis Drive NW - Huntsville, AL 35806 - USA Check us out at: http://digium.com & http://asterisk.org _______________________________________________ asterisk-app-dev mailing list asterisk-app-dev@xxxxxxxxxxxxxxxx http://lists.digium.com/cgi-bin/mailman/listinfo/asterisk-app-dev
