[Galene] Re: Fw: Re: Versioning the Galene protocol

[Juliusz Chroboczek <jch@irif.fr>]

> Why support multiple versions of the same protocol? Wouldn't that only
> complicate things at the Galene side? I don't mind personally to stick
> to a version of the protocol, that was made to work with that particular
> version of Galene.

If the server cannot support multiple versions, then every change to the
protocol breaks all non-web clients.  (There's Galene-stream already, and
I'd really like to see a native client for Android that can do screenshare.)

> Would that be to be able to subscribe to certain kind of messages? (e.g. chat)

In order to join a group, you currently do:

    C->S: join(groupname)
    S->C: joined(groupname)
    S->C: chathistory, chathistory, chathistory
    C->S: request(audio, video)

There is no way to avoid receiving the chat history, and there's no way to
avoid receiving chat messages.  The proposed protocol is

    C->S: join(groupname)
    S->C: joined(groupname)
    C->S: request(audio, video, chat)
    S->C: chathistory, chathistory, chathistory

Unless you explicitly request chat, you're not going to get the burst of
chathistory messages, and you're not going to get any chat messages.

> Would it be a problem to just be able to use newly added group actions
> in the protocol without explicitly having to mention that it's part
> of an extension?

If you send a groupaction that the server doesn't know about, you'll
receive an error message.  It would be useful to be able to avoid exposing
a group action in the UI if the server doesn't support it, and that's what
the extension mechanism could be useful for.  Whether this will prove
necessary will depend on whether useful native clients surface.

Ideally, of course, we'd have a single protocol that is used across
multiple servers.  Unfortunately, the only standardised videoconferencing
protocols are SIP and Jingle, both of which are somewhat strange (streamed
XML, giggle).

-- Juliusz