From 56770630c06b93188174fe371b2bd2d7627e6808 Mon Sep 17 00:00:00 2001 From: Peter Saint-Andre Date: Mon, 2 Dec 2013 20:17:57 -0700 Subject: [PATCH] 0.0.2 --- inbox/sox.xml | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/inbox/sox.xml b/inbox/sox.xml index 1b27bd22..3321c002 100755 --- a/inbox/sox.xml +++ b/inbox/sox.xml @@ -28,6 +28,12 @@ fluffy@cisco.com fluffy@cisco.com + + 0.0.2 + 2013-12-02 + psa +

Clarified scope and intent of the protocol.

 + 0.0.1 2013-06-12 @@ -38,8 +44,8 @@

The Session Description Protocol (SDP) &rfc4566; is widely used to communicate information about media sessions, typically using the offer/answer model &rfc3264;. For example, when the Session Initiation Protocol (SIP) &rfc3261; is used for establishing media sessions, the payloads of the SIP messages contain SDP payloads. The use of SDP continues to gain force, since SDP has been adopted for use in the WebRTC technologies being defined at the &IETF; and &W3C; for real-time communication among web browsers.

-

Some user agents that might want to participate in WebRTC interactions use XMPP as their primary or only communication channel. For example, a browser-based XMPP application might use a JavaScript library that connects to an XMPP server using &xmppoverwebsocket; or using &xep0124; and &xep0206;. Although such an application could use &xep0166; and &xep0167; between the client and the server, converting the Jingle XML format into SDP (and associated SIP headers) might require use of a server-side gateway, and such a gateway might introduce unnecessary complexity into the system (e.g., keeping session state in the gateway). Enabling the user agent to natively send SDP (and a minimal set of SIP headers) can make it easier for XMPP client developers to build real-time communication applications using existing SDP and SIP libraries, especially in the context of WebRTC.

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By specifying a way to send SDP/SIP over XMPP (a.k.a. "SoX"), this document effectively defines another reliable transport method for SIP/SDP messages. However, it is envisioned that this method will be used only by XMPP-only endpoints, not by native SIP or dual-stack SIP/XMPP &cusax; endpoints. It is important to note that SoX is not intended to deprecate Jingle, only to provide a convenient way to reliably transport SIP/SDP traffic for communication with native SIP and dual-stack SIP/XMPP endpoints. Finally, because SoX payloads contain only minimal SIP headers (needed for message delivery in certain scenarios) and SDP content, the method is not designed for sending arbitrary SIP message bodies, only SDP.

+

Some user agents that might want to participate in WebRTC interactions use XMPP as their primary or only communication channel. For example, a browser-based XMPP application might use a JavaScript library that connects to an XMPP server using &xmppoverwebsocket; or using &xep0124; and &xep0206;. Although such an application could use &xep0166; and &xep0167; between the client and the server, converting the Jingle XML format into SDP (and associated SIP headers) might require use of a server-side gateway, and such a gateway might introduce unnecessary complexity into the system (e.g., keeping session state in the gateway). Enabling the user agent to natively send SDP (and a minimal set of SIP headers) can make it easier for XMPP client developers to build real-time communication applications using existing SDP and SIP libraries, especially in the context of WebRTC. Even outside of WebRTC, the ability to send SDP/SIP over XMPP can be useful in deployments where XMPP-capable endpoints need to communicate with SIP endpoints such as IP phones.

+

By specifying a way to send SDP/SIP over XMPP (a.k.a. "SoX"), this document effectively defines a reliable transport method for SIP/SDP messages. However, it is envisioned that this method will be used only by XMPP-only endpoints, not by native SIP or dual-stack SIP/XMPP &rfc7081; endpoints. It is also important to note that SoX is not intended to replace Jingle as a general-purpose method for negotiating media sessions among XMPP entities; instead, it provides a convenient way to reliably transport SIP/SDP traffic for communication from XMPP-only endpoints to native SIP and dual-stack SIP/XMPP endpoints. Finally, because SoX payloads contain only minimal SIP headers (needed for message delivery in certain scenarios) and SDP content, the method is not designed for sending arbitrary SIP message bodies, only SDP.

 @@ -128,7 +134,7 @@ a=sendrecv -

Address mapping between SIP and XMPP can be a challenge. See &xmppsipcore; for details.

+

Address mapping between SIP and XMPP can be a challenge. See &stoxcore; for details.

The 'to' attribute and 'from' attribute of the XMPP &MESSAGE; stanza need not match the "To" header and "From" header of the SoX payload. For example, the sender might know (based on vCard data or a directory lookup) that the SIP address of the intended recipient is different from the XMPP address of the intended recipient. This is possible in so-called CUSAX scenarios; although the CUSAX specification recommends that all SDP signalling be sent over SIP rather than XMPP, the sender might be an XMPP-only endpoint and the intended recipient might be a CUSAX endpoint.

However, in general it is easier for a user agent to simply set the SIP "To" and "From" headers to the same identifiers (JIDs) used for the XMPP 'to' and 'from' attributes.