The WebSocket protocol "Last Call"

http://datatracker.ietf.org/doc/draft-ietf-hybi-thewebsocketprotocol/

by frsyuki • 15 years ago

58 12 15 years ago

datatracker.ietf.org

andypants• 15 years ago

Finally! I'm sick of web hosts claiming the protocol is still changing constantly, so they won't support websockets on their servers.

pilif2• 15 years ago

in their defense though, that was (and is - until the final RFC is released) true. Depending on your infrastructure (reverse proxies, firewalls) supporting just one version can already be painful.

Supporting different versions, incompatible to each other is even more painful.

And as a generic host you can't make all your customers constantly update their application especially when you consider that various browsers out there support (or don't support) different revisions of the protocol.

braindead_in• 15 years ago

Is there a good overview of websockets? I just glanced at the spec and it looks quite complex. Especially the part about framing. Do websockets have any relation to TCP sockets? If over TCP, why do they use their own framing?

udp• 15 years ago

Because TCP doesn't provide any framing - it's just a stream of data. Text based protocols usually use newlines as delimiters, and binary protocols usually prefix each message with a size.

metabrew3• 15 years ago

Is there a good 'diff', detailing what's changed between revisions?

I need to read up on the latest version - anyone know if it avoids breaking http, and will work with proxies out of the box? (ie no essential body data without a content-length header)

yuhong• 15 years ago

Yep, they use masking to prevent security holes in proxies from being exploited.

mloughran• 15 years ago

Yes, you can get a text diff from http://datatracker.ietf.org/doc/draft-ietf-hybi-thewebsocket...

pilif2• 15 years ago

As people here seem to really like and actively use WebSockets already, let me ask a question: How well does this behave with various proxy servers on both ends (client and server)?

I have this nagging feeling that yet another cool technology will probably not be usable for the foreseeable future because it gets broken in unpredictable ways by either forced proxy servers or, my bane of existence, personal firewalls.

Are there numbers out there about percentages of successful connections (though considering browser support, those numbers are probably skewed because this is still limited to early adopters which either don't run personal firewalls or are able to fix them)?

If connections fail, how do they fail?

metabrew3• 15 years ago

The version of websockets currently in the wild (-76) doesn't play well with proxies at all.

The handshake requires sending 8 bytes of body data, without a suitable content-length header. Without the content-length header, http proxies won't pass on those 8 bytes, so handshakes fail.

Hopefully this is addressed in the newest revision.

speckledjim2• 15 years ago

All 3 versions are reasonably successful, and in any event, it's not rocket science to try websocket and fallback on comet upon failure.

The latest version is probably the most robust if your ISP likes fiddling with your HTTP though.

The WebSocket protocol "Last Call"

Related Stories