SIP Methods
This page describes the Sip methods that are handled internally in Yate and how to enable the ones that are generically handled.
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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
- PRACK - Similar to ACK, but a provisional confirmation.
- 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
In Yate some SIP Methods are handled internally while others are handled generically.
Internally handled Methods
Internally handled methods means that if module ysipchan is enabled in Yate then no message like sip.methodname can be generated for them.
The methods handled internally by Yate are:
- INVITE
- CANCEL
- ACK
- BYE
- The above methods are handled internally by Yate if ysipchan is enabled in yate.conf, so that means that no message can be generated for them.
- REFER - if is set true in section [general], it is handled from [transfer] section
- OPTIONS - default is true but can be handled from configuration in section [general]
- REGISTER - if is set true in section [general] ] then it can be handled in [registrar] section. But for this to work you must
- INFO - if method is received in a dialog it is handled internally
- PRACK - internally, is set by default to false
Generically handled Methods
- INFO - this SIP method if is 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}<status><basic>\(.*\)</basic></status>=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
