From owner-freebsd-hackers Mon Feb 2 01:10:55 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id BAA29454 for hackers-outgoing; Mon, 2 Feb 1998 01:10:55 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from manuel.nta.no (manuel.nta.no [128.39.1.196]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id BAA29437 for ; Mon, 2 Feb 1998 01:10:48 -0800 (PST) (envelope-from Igor.Alekseev@kjeller.fou.telenor.no) From: Igor.Alekseev@kjeller.fou.telenor.no X400-Received: by mta tf in /PRMD=telenor/ADMD=TELEMAX/C=no/; Relayed; Mon, 2 Feb 1998 10:10:25 +0100 Date: Mon, 2 Feb 1998 10:10:25 +0100 X400-Originator: Igor.Alekseev@kjeller.fou.telenor.no X400-Recipients: non-disclosure:; X400-MTS-Identifier: [/PRMD=telenor/ADMD=TELEMAX/C=no/;1268 98/02/02 10:10] Content-Identifier: 1268 98/02/02 Alternate-Recipient: Allowed Message-ID: <"1268 98/02/02 10:10*/G=Igor/S=Alekseev/OU=kjeller/O=fou/PRMD=telenor/ADMD=TELEMAX/C=no/"@MHS> To: freebsd-hackers@FreeBSD.ORG Subject: help with real time monitoring of TCP control variables Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG X-To-Unsubscribe: mail to majordomo@FreeBSD.org "unsubscribe hackers" Hi, I am doing network performance evaluations with FreeBSD 2.2.5 with ENI ATM card, using HARP atm software. Is it possible to do the real time monitoring (by real time I mean synchronised with tcpdump output) of TCP connection control variables for a particular connection, such as SND.NXT, CWND, SSTHRESH, RTT estimate? Is there a standard mechanism for doing this kind of thing or is some source code change required of tcp code? In any case, could anyone, please give me a hint on the best way to do it? What I need - is basically dumping the above variables into a file along with timestamp, say every time a segment is received or sent. It does not have to be anything extremely versatile, just quick and easy hack will suffice for the time being. By looking at the archives of this list, I found that such discussion was held 2.5 years ago, but I did not find any definite answer to the question posed. Maybe things have changed since then? Thanks in advance, Igor V. Alekseev Visiting reseacher, Telenor, Norway