Re: [hybi] With deflate-stream / websocket traceroute action

[Andy Green <[e-mail]>]

On 02/25/2011 08:02 AM, Somebody in the thread at some point said:

Hi -

> What if we'd like to introduce a new control frame that is intended
> to communicate with intermediaries (imagine, trace-route mechanism,
> etc.) in the future, then the 'compression' layer gets in the way
> and all intermediaries have to decompress stream all the time.

The intermediaries have to rewrite the compression too if there's ever 
anything they don't pass through, if the compression has any state held 
at both ends.


I thought about traceroute a bit when I wrote libwebsockets-test-ping 
which uses PING / PONG control frames just like normal ping app.

In fact you can do traceroute just with PING / PONG if the standard 
allowed for

  1) PONG MAY contain additional text after the PING payload echo

  2) PING MUST contain a TTL byte at the start

  3) Intermediaries MAY decrement the TTL when passing on PING

  4) PONG SHOULD be issued by intermediary IF TTL = 0 after the 
decrement and MUST be by the endpoint regardless of TTL

  5) When PONG issued, intermediary or endpoint MAY append its ID text

-Andy