Path: utzoo!attcan!uunet!ogicse!ucsd!ucbvax!MCIMAIL.COM!0004219666
From: 0004219666@MCIMAIL.COM (Bob Stine)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Looking for probes for TCP/IP
Message-ID: <14901114140441.0004219666NB4EM@mcimail.com>
Date: 14 Nov 90 14:04:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 31

>... I plan to implement an application which we think has characteristics
>typical of visualization applications ...[t]hen tap in the protocols at
>different levels and take various measurements to identify where the
>bottlenecks are (if any).  
> ...
>    The measurements we would like to take include:
>       (i)     Dynamic queue length at the various queues
>       (ii)    Various delays a packet experiences
> ...
>
>Are there probe and measurement utility programs which will allow us
>to take these measurements without any kernel modifications? 

Christos,

You might check RFC 1147, "A Network Management Tool Catalog," for a list of
several tools.  Unfortunately, to the best of my recollection, the only tools
capable of monitoring actual queue lengths require some (well-documented) kernel
mods.  I could be wrong about this.  My gut feeling, however, is that getting
the queue lengths will require some special instrumentation, which in turn will
require kernel mods.

At any rate, I recommend that you take a look at the catalog entry describing
NETMON and iptrace, developed by Allison Mankin, of MITRE.  NETMON is
essentially kernel instrumentation for BSD-UNIX.  You might conclude that
avoiding mods to the kernel is not a hard-and-fast requirement.

For background on TCP/IP, I'd also recommend that you read RFC 1122,
"Requirements for Internet hosts -- communication layers."

- Bob Stine