Message Multiplexing (memux) Charter
Name | Area |
| Directors |
| Description | Goals &
Milestones | Background
Working Group Name
Message Multiplexing (memux)
Transport Area Directors
Responsible Area Director
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Description of Working Group
The goal of this working group is to develop a lightweight protocol that
delivers multiplexed bidirectional reliable ordered message streams over
a bidirectional reliable ordered byte stream protocol (such as TCP).
This is envisioned as a relatively low-level piece of other protocol stacks,
fitting between, e.g., TCP and RPC. The length of a message is unrestricted
(e.g., not bounded by layer 2 or 3 packet sizes), and the payload of a
message is also unrestricted; such a message can be used directly, e.g.,
as a request or a response in an application-level request/response protocol.
Within each message stream, the messages are delivered reliably and in
order (as are bytes in TCP). Each message may be passed as a series
of chunks, so that the multiplexing does not introduce unnecessary synchronization
between streams. The MEMUX protocol will be layered on top of bidirectional
reliable ordered byte stream protocols (such as, but not limited to, TCP),
and multiplex many message streams over a single byte stream connection.
It should be possible to put multiple message chunks into one IP packet.
The MEMUX protocol will be lightweight in these two ways: (1) its overhead,
in bytes on the wire, will be low, and (2) opening and closing new message
streams, once the byte stream connection is established, will take few
bytes and impose no round-trip delays. The value of the MEMUX protocol
is twofold: (1) it provides a commonly useful service abstraction (bidirectional
reliable ordered arbitrary-sized message stream), and (2) the multiplexing
achieves the same results as state sharing between parallel TCP streams
(which is not widely available today). The second value may cease
to be unique in the future (when TCP and/or replacements that effectively
share state between parallel connections become widely available), but
having built other protocols and implementations on top of the service
provided by MEMUX enables a smooth transition to a MEMUX-- that delivers
the same service while doing no multiplexing of its own.
An informational goals document for the MEMUX protocol.
Standards-track specification of the MEMUX protocol.
Out of Scope
Replacing TCP; MEMUX is to be layered over TCP, not replace it.
Underlying connection agility; MEMUX will transport a given message stream
over exactly one byte stream.
Datagrams; MEMUX provides message stream connections.
Control channel vs. data channel separation; that distinction is to be
made at a higher layer, which will use MEMUX's service for whichever channel(s)
Integrated security functions; security is to be done above and/or below
Goals and Milestones
1999/03 - WG chartered.
1999/06 - Internet-Draft of goals document.
1999/10 - MEMUX specification submitted to IESG for publication as Proposed
Interest in a multiplexing protocol appeared at IETF-43 in the HTTPNG,
RUTS, SIGTRAN, MEGACO, and AAA meetings. The HTTP-NG
proponents submitted a draft multiplexing protocol (draft-gettys-webmux-00.txt)
on 1 August 1998 as part of the HTTP-NG suite.