Ethereal-dev: Re: [ethereal-dev] An idea

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From: Guy Harris <gharris@xxxxxxxxxxxx>
Date: Tue, 15 Feb 2000 10:19:52 -0800
On Tue, Feb 15, 2000 at 09:15:12AM +0100, andreas.sikkema@xxxxxxxxxxx wrote:
> 
> 
> 
> 
> > Presumably, in that case, frames 3, 4, 6, and 7 would all probably be
> > HTTP, so you might want to flag the entire connection between machine A
> > port 1010 and machine B port 2020 as HTTP - preferably in one operation,
> > not 4 (or more).
> 
> But not necesarrily http!

I was just using HTTP as an example.

> I might know that when I receive a certain message a certain time later
> there might be unrecognized (because it's not a known port) messages
> exchanged...
> 
> Suppose a protocol uses messagetype A to control a connection and
> messagetype B to exchange data.

Over the same connection (for connection-oriented transport protocols)
or host/port pair (connectionless transport protocols), or over
different connections or host/port pairs?

I.e., in this example:

> 	Sender 1				Sender 2
> 1	A:connection_req		
> 2					A:req_ack
> 3	A:set_connection		
> 4					A:set_ack
> 5	A:set_ports			
> 6					A:portset_ack
> 7	B:data				
> 8	B:data
> 9					B:data
> 10	A:connection_end		
> 11					A:end_ack
> 
> In the current situation messages 7,8,9 are not recognized, but from the
> information in messages 5 and 6 _I_ know that the messages 7,8,9 are a
> known format,

it sounds as if all the messages are going over the same (TCP, say)
connection or (UDP, say) host/port pair - or does the "set_ports" and
"portset_ack" imply that messages 7-9 are going over a different
connection or host/port pair?

> it's just that ethereal has no way of knowing that.

Why not? Why can it not infer from messages 1-6 that messages 7, 8, and
9 are of protocol type B, if it's capable of understanding message type
A?