頭を整理するためのMemo

GoogleTalkで使われているというjingle

XEP-0166: Jingle
XMPP protocol extension for initiating and managing peer-to-peer media sessions between two XMPP entities in a way that is interoperable with existing Internet standards
既存のInternet標準と共存できる方法で、２つのXMPPentities間でP2Pメディアセッションを確立、管理するためのXMPPプロトコルの拡張。

In essence, Jingle enables two XMPP entities (e.g., [email protected] and [email protected]) to set up, manage, and tear down a multimedia session. The negotiation takes place over XMPP, and the media transfer takes place outside of XMPP. The simplest session flow is as follows:
セッションのnegotiationはXMPPで、メディアはXMPP外で。

Initiator Responder  
| |  
| session-initiate |  
|\---\---\---\---\---\---\---\---\---->|  
| ack |  
|< \---\---\---\---\---\---\---\---\----|  
| [transport negotiation] |  
|<\---\---\---\---\---\---\---\---\--->|  
| session-accept |  
|< \---\---\---\---\---\---\---\---\----|  
| ack |  
|\---\---\---\---\---\---\---\---\---->|  
| AUDIO (RTP) |  
|< ===========================>|  
| |

Example 1. Initiator sends session-initiate

<iq from='[email protected]/orchard'  
id='jingle1'  
to='[email protected]/balcony'  
type='set'>  
<jingle xmlns='urn:xmpp:tmp:jingle'>  
action='session-initiate'  
initiator='[email protected]/orchard'  
sid='a73sjjvkla37jfea'>  
<content creator='initiator' name='voice'>  
<description xmlns='urn:xmpp:tmp:jingle:apps:rtp' media='audio'><payload -type id='96' name='speex' clockrate='16000'/> <payload -type id='97' name='speex' clockrate='8000'/> <payload -type id='18' name='G729'/> <payload -type id='0' name='PCMU' /> <payload -type id='103' name='L16' clockrate='16000' channels='2'/> <payload -type id='98' name='x-ISAC' clockrate='8000'/> </description></p> <transport xmlns='urn:xmpp:tmp:jingle:transports:ice-udp'/> </content>

  
</jingle>  
</iq>

Example 2. Responder acknowledges session-initiate ```xml ```

After successful transport negotiation (not shown here), the responder accepts the session by sending a session-accept action to the initiator.

Example 3. Responder definitively accepts the session

<iq from='[email protected]/balcony'
id='accept1'  
to='[email protected]/orchard'  
type='set'>  
<jingle xmlns='urn:xmpp:tmp:jingle'  
action='session-accept'  
initiator='[email protected]/orchard'  
responder='[email protected]/balcony'  
sid='a73sjjvkla37jfea'>  
<content creator='initiator' name='voice'>  
<description xmlns='urn:xmpp:tmp:jingle:apps:rtp' media='audio'><payload -type id='97' name='speex' clockrate='8000'/> <payload -type id='18' name='G729'/> </description></p> <transport xmlns='urn:xmpp:tmp:jingle:transports:ice-udp'> <candidate component='1'

  
foundation='1'  
generation='0'  
ip='192.0.2.3'  
network='1'  
port='45664'  
priority='1678246398'  
protocol='udp'  
pwd='asd88fgpdd777uzjYhagZg'  
type='srflx'  
ufrag='8hhy'/>  
</transport> </content>  
</jingle>  
</iq>

ここで ・受信側が使えるpayload-typeに絞り込まれて(?)レスポンス ・IPアドレスとポートが受信側のjulietから送信側のromeoへ行ってる。

IPアドレスとポートはどうやって取得してるんだろ。
この例では192..ってローカルのIPだけどNAT超えの時は、NATの外側のグローバルIPとポートが必要でしょう。

XEP-0166: Jingleでは省略されてる transport negotiation について調べる。