Re: [hybi] hum #3: Message

[Ian Hickson <[e-mail]>]

On Thu, 5 Aug 2010, Salvatore Loreto wrote:
> 
>    * A message may be composed of one or more "frame"s
>    * Each frame has a length indication, encoded in a fixed number of
>      bits (where that lengths is fixed in the specification to be written)

When transfering large blocks of data, chunking is quite inefficient. This 
means that we'd need to make sure that the fixed width field is at least 
long enough to handle large chunks of data.

At terabit Ethernet speeds, 32 bits is not enough since you could transfer 
that much in mere seconds, so presumably we'll use 64 bits.

Do we really want a length that long? 

The alternative is variable width lengths, which are no more complicated 
to implement than fragmentation, and which do not preclude using 
fragmentation either, and which remain compact at any length.


>    * A message may be composed of one or more "frame"s

I think we should obtain real-world experience with how people use 
WebSockets before we add fragmentation support to the technology. Since it 
can easily be worked around at the application layer (by having 
fragmentation in the subprotocol), we can easily collect information on 
how people are using this after we have initial deployments.


Other relevant e-mails on the subject from other people:

http://www.ietf.org/mail-archive/web/hybi/current/msg02841.html
http://www.ietf.org/mail-archive/web/hybi/current/msg02830.html
http://www.ietf.org/mail-archive/web/hybi/current/msg02892.html

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'