Jingle In-Band Bytestreams Transport

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Jingle In-Band Bytestreams Transport This specification defines a Jingle transport method that results in sending data via the In-Band Bytestreams (IBB) protocol defined in XEP-0047. Essentially this transport method reuses XEP-0047 semantics for sending the data and defines native Jingle methods for starting and ending an IBB session. &LEGALNOTICE; xxxx ProtoXEP Standards Track Standards XMPP Core XEP-0047 jingle-ibb &stpeter; 0.0.1 2009-02-10 psa Rough draft.

&xep0166; defines a framework for negotiating and managing data sessions over XMPP. In order to provide a flexible framework, the base Jingle specification defines neither data transport methods nor application formats, leaving that up to separate specifications. The current document defines a transport method for establishing and managing data exchanges between XMPP entities using the existing In-Band Bytestreams (IBB) protocol specified in &xep0047;. This "jingle-ibb" method results in a streaming transport method suitable for use in Jingle application types where packet loss cannot be tolerated (e.g., file transfer); however, because the "jingle-ibb" transport method sends data over the XMPP channel itself (albeit not the Jingle signalling channel), it is intended as a transport of last resort when other streaming transports cannot be negotiated.

The approach taken in this specification is to use the existing IBB mechanisms described in XEP-0047 for transporting the data, and to define Jingle-specific methods only to start and end the in-band bytestream.

The basic flow is as follows.

|
  |  ack                       |
  |<---------------------------|
  |  session-accept            |
  |<---------------------------|
  |  ack                       |
  |--------------------------->|
  |  IBB "SESSION"             |
  |<==========================>|
  |  session-terminate         |
  |<---------------------------|
  |  ack                       |
  |--------------------------->|
  |                            |
  ]]>

This flow is illustrated in the following examples (to prevent confusion these use a "stub" transport instead of a real application type).

First the initiator sends a Jingle session-initiate request.

action='session-initiate' initiator='romeo@montague.lit/orchard' sid='a73sjjvkla37jfea'> ]]>

Note: The Jingle IBB Transport Method defines one attribute in addition to those defined in XEP-0047: the 'stanza' attribute. This attribute specifies whether the initiator intends to send IBB data using &MESSAGE; or &IQ; stanzas, but is purely advisory. The default value is "iq", and it is RECOMMENDED to send IBB data using IQ stanzas instead of message stanzas because IQ stanzas provide feedback to the sender regarding delivery to the recipient (e.g., if the recipient is on a small pipe and cannot handle a large volume of IBB packets in quick succession).

The responder immediately acknowledges receipt (but does not yet accept the session).

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If the offer is acceptable, the responder returns a Jingle session-accept and the initiator acknowledges the session-accept.

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The initiator then immediately begins sending IBB packets using an IQ-set for each chunk as described in XEP-0047, and the responder acknowledges each IQ-set.

qANQR1DBwU4DX7jmYZnncmUQB/9KuKBddzQH+tZ1ZywKK0yHKnq57kWq+RFtQdCJ WpdWpR0uQsuJe7+vh3NWn59/gTc5MDlX8dS9p0ovStmNcyLhxVgmqS8ZKhsblVeu IpQ0JgavABqibJolc3BKrVtVV1igKiX/N7Pi8RtY1K18toaMDhdEfhBRzO/XB0+P AQhYlRjNacGcslkhXqNjK5Va4tuOAPy2n1Q8UUrHbUd0g+xJ9Bm0G0LZXyvCWyKH kuNEHFQiLuCY6Iv0myq6iX6tjuHehZlFSh80b5BVV9tNLwNR5Eqz1klxMhoghJOA ]]> ]]>

Once the parties have finished using the bytestream (e.g., because a complete file has been sent), either party can send a Jingle session-terminate action.

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The other party then acknowledges the session-terminate and the Jingle session is finished.

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The same processing rules and usage guidelines defined in XEP-0047 apply to the Jingle IBB Transport Method.

The same security considerations defined in XEP-0047 apply to the Jingle IBB Transport Method.

This document requires no interaction with &IANA;.

This specification defines the following XML namespace:

urn:xmpp:jingle:transports:raw-udp:1

Upon advancement of this specification from a status of Experimental to a status of Draft, the ®ISTRAR; shall add the foregoing namespace to the registry located at &NAMESPACES;, as described in Section 4 of &xep0053;.

&NSVER;

The XMPP Registrar shall add to its registry of Jingle transport methods a definition for the "jingle-ibb" transport method. The registry submission is as follows:


  ibb
  A method for exchanging data over In-Band Bytestreams.
  streaming
  XEP-xxxx

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