Re: Guidance needed on well known ports

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu,  6 Apr 2006 21:37:49 -0400 (EDT), jnc@xxxxxxxxxxxxxxxxxxx (Noel
Chiappa) wrote:

>     > From: Joe Touch <touch@xxxxxxx>
> 
>     > TCPMUX doesn't 'handoff'. It expects that .. the service desired is
>     > served off of its port once opened after the initial exchange
>     > (in-band).
>     > .. The downside is that it then forces a two-step demultiplexing of
>     > incoming packets; there may be utility in a variant that allows the
>     > dest port to be unbound and later filled-in, or changed during the
>     > connection, so that services can be more efficiently demultiplexed.
> 
> I'm missing something here. A TCP connection is identified by the (srcaddr,
> sport, dstaddr, dport) tuple. TCB's are looked up by this tuple. Connections
> to TCPMUX will all have the same dstaddr/dport, but will presumably have
> different srcaddr's, and (presumably) random sport's, and can be
> distinguished that way.
> 
> Why can't the TCPMUX listener just bind the correct application to the TCB
> (after figuring out what the appropriate application is), and then forget
> about the connection, leaving it entirely to the application to deal with?
> All packets which belong to that connection will automatically go to that
> TCB, and thence to the application, with no second layer of demux needed.
> Am I missing something?
> 
No -- that's precisely how it works.


		--Steven M. Bellovin, http://www.cs.columbia.edu/~smb

_______________________________________________

Ietf@xxxxxxxx
https://www1.ietf.org/mailman/listinfo/ietf

[Index of Archives]     [IETF Annoucements]     [IETF]     [IP Storage]     [Yosemite News]     [Linux SCTP]     [Linux Newbies]     [Fedora Users]