SIP Methods

Revision as of 13:24, 9 November 2012

This page describes the Sip methods that are handled by default in Yate and how to enable the ones that are not generically handled.

What is a SIP Request Method?

SIP Request Method defines the nature and the purpose of the SIP request.

SIP Methods:

• INVITE - Requests a session.
• ACK - Final response to the INVITE
• OPTIONS - Ask for server capabilities
• BYE - Terminates a session
• CANCEL - Cancel any pending requests.
• REGISTER - Registers the client with the server according to the address in the To he
• INFO - Sends information in the middle of a session that doesn't modify the session's state.
• SUBSCRIBE -Subscribes the device for an event notification.
• NOTIFY - Notifies all subscribers of an event.
• PUBLISH - Publishes an event to a server.
• REFER - Asks the client to issue a SIP request, typically a call transfer.
• MESSAGE - Sends an instant message using SIP.
• UPDATE - Modifies a session's state without altering the dialog state.

SIP Methods in Yate

Generically handled Methods

Some standard SIP methods can be handled internally by Yate like INVITE, CANCEL, ACK, BYE, REFER, OPTIONS and REGISTER.

For example SIP method INFO in a dialog is handled internally by Yate but dialogless is handled generically (by using parameter lazy100 in ysipchan.conf).

Enabling additional Methods

Use section [methods] from ysipchan.conf to allow/restrict the processing of specific SIP methods. For enabled methods yate will generate internal messages with name sip.<methodname> that can be handled from other modules.

Examples

Enable MESSAGE Method

This example allows chat and short files transfer between Twinkle clients using MESSAGE Request Method.

A MESSAGE request method transports instant messages using SIP.

regexroute.conf:

[extra]
sip.message=120
sip.publish=120
msg.route=25
msg.execute=90

[sip.message]
${xsip_type}^$=415
.*=echo Got SIP MESSAGE type '${xsip_type}' ${xsip_body_encoding} from '${username}': ${xsip_body}
.*=enqueue msg.execute;caller=${caller};called=${called};\
 domain=${domain};callto=lateroute/${called};\
 body_encoding=${xsip_body_encoding};type=${xsip_type};text=${xsip_body}
.*=200
 
[sip.publish]
${xsip_type}^application/pidf+xml$^=415
${xsip_body}\(.*\)=echo Got SIP PRESENCE from '${username}': 
.*=200

[msg.route]
.*=rename call.route;message=msg.route

[msg.execute]
${callto}^sip/\(sip:.*\)$=rename xsip.generate;\
method=MESSAGE;uri=;sip_From=<sip:${caller}@${domain$nosuch.dom}>;\

xsip_type=${type$text/plain};xsip_body_encoding=${body_encoding};\
xsip_body=${text}

In ysipchan.conf:

[general]
maxpkt=4096
generate=yes

[methods]
message=yes
publish=yes

Enable SUBSCRIBE Method

ysipchan.conf

[methods]
subscribe=yes

You then configure the allowed events for subscribing in sipfeatures.conf and define the logic for SUBSCRIBE/NOTIFY in subscription.conf.

See also

• List of SIP request methods
• Subscriptions module
• SIP Features Module