4.11 P2P Subscription and XPIDF Presence Format Example

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This example demonstrates how XPIDF format can be used in a P2P presence subscription.

P2P subscription and XPIDF presence format example

Figure 11: P2P subscription and XPIDF presence format example

User1 sends a SUBSCRIBE request to user2 to create a subscription for the presence event-package. This is indicated by the Event: presence header in the SUBSCRIBE request. The Accept header indicates that user1 accepts the XPIDF Presence Document format.

 SUBSCRIBE sip:user2@193.12.62.199 SIP/2.0 
 Via: SIP/2.0/UDP 193.12.63.150:13695 
 Max-Forwards: 70 
 From: "user1" <sip:host1>;tag=12e78ca4-85f7-4094-bbdf-e8e819188ae6 
 To: <sip:user2@193.12.62.199> 
 Call-ID: 21824beb-0ee4-4953-ad36-745a0614a0e9@193.12.63.150 
 CSeq: 1 SUBSCRIBE 
 Contact: <sip:193.12.63.150:13695> 
 User-Agent: Windows RTC/1.2 
 Event: presence 
 Accept: application/xpidf+xml 
 Content-Length: 0

User2 sends a 200 OK response to indicate that the SUBSCRIBE request has been accepted. The 200 OK response does not have a body.

 SIP/2.0 200 OK 
 From: "user1" <sip:host1>;tag=12e78ca4-85f7-4094-bbdf-e8e819188ae6 
 To: <sip:user2@193.12.62.199>;tag=112040_T193.12.62.199 
 Call-ID: 21824beb-0ee4-4953-ad36-745a0614a0e9@193.12.63.150 
 CSeq: 1 SUBSCRIBE 
 Via: SIP/2.0/UDP 193.12.63.150:13695 
 Expires: 28800 
 Content-Length: 0

User2 then sends a NOTIFY request to user1 to communicate its presence state, which is online in this example. The body of the NOTIFY request is an XML in the XPIDF format. The XML includes the presentity whose presence information is being communicated, the address element representing a particular endpoint for the presentity and the presence status for that endpoint.

 NOTIFY sip:193.12.63.150:13695 SIP/2.0 
 From: <sip:user2@193.12.62.199>;tag=112040_T193.12.62.199 
 To: "user1" <sip:host1>;tag=12e78ca4-85f7-4094-bbdf-e8e819188ae6 
 Call-ID: 21824beb-0ee4-4953-ad36-745a0614a0e9@193.12.63.150 
 CSeq: 2 NOTIFY 
 Via: SIP/2.0/UDP 193.12.62.199 
 Content-Length: 356 
 Contact: sip:user2@193.12.62.199 
 Event: presence 
 Content-Type: application/xpidf+xml 
  
 <?xml version="1.0"?> 
 <!DOCTYPE presence 
  PUBLIC "-//IETF//DTD RFCxxxx XPIDF 1.0//EN" "xpidf.dtd">  
 <presence>
 <presentity uri="sip:user2@193.12.62.199;method=SUBSCIRBE"/>
 <atom id="1002">
 <address uri="sip:user2@193.12.62.199 priority="0.600000">
     <status status="open"/>
     <msnstatus substatus="online"/>
 </address>
 </atom>
 </presence>

User1 acknowledges the receipt of the notification by sending a 200 OK response. The 200 OK response does not have a body.

 SIP/2.0 200 OK 
 Via: SIP/2.0/UDP 193.12.62.199 
 From: <sip:user1@193.12.62.199>;tag=112040_T193.12.62.199 
 To: "user2" <sip:host2>;tag=12e78ca4-85f7-4094-bbdf-e8e819188ae6 
 Call-ID: 21824beb-0ee4-4953-ad36-745a0614a0e9@193.12.63.150 
 CSeq: 2 NOTIFY 
 User-Agent: Windows RTC/1.2 
 Content-Length: 0