From owner-freebsd-hackers Mon May 29 11:19:15 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id LAA04095 for hackers-outgoing; Mon, 29 May 1995 11:19:15 -0700 Received: from cs.pdx.edu (root@cs.pdx.edu [131.252.20.183]) by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id LAA04088 for ; Mon, 29 May 1995 11:19:14 -0700 Received: from sirius.cs.pdx.edu (root@sirius.cs.pdx.edu [131.252.20.199]) by cs.pdx.edu (8.6.10/CATastrophe-12/23/94-P) with ESMTP id KAA16968; Mon, 29 May 1995 10:43:41 -0700 for Received: from localhost (jrb@localhost.cs.pdx.edu [127.0.0.1]) by sirius.cs.pdx.edu (8.6.10/CATastrophe-9/18/94-C) with ESMTP id KAA22513; Mon, 29 May 1995 10:42:09 -0700 for Message-Id: <199505291742.KAA22513@sirius.cs.pdx.edu> To: hackers@FreeBSD.org Subject: Van Jacobson releases vat/sd/wb for linux Date: Mon, 29 May 1995 10:42:08 -0700 From: James Binkley Sender: hackers-owner@FreeBSD.org Precedence: bulk Anything that could be done to get them to make vat/sd/wb binaries for freebsd? The following forwarded from the rem-conf mbone list. In any case, the discussion of multicast problems is interesting. regards, Jim Binkley jrb@cs.pdx.edu --------------------------------------------------------- ------- Forwarded Message Return-Path: rem-conf-request@es.net Return-Path: Received: from osi-west.es.net (osi-west.es.net [128.55.32.32]) by cs.pdx.edu (8.6.10/CATastrophe-12/23/94-P) with SMTP id BAA00659; Sat, 27 May 1995 01:47:45 -0700 for Received: from rx7.ee.lbl.gov by osi-west.es.net with ESnet SMTP (PP); Sat, 27 May 1995 00:08:46 -0700 Received: by rx7.ee.lbl.gov (8.6.12/1.43r) id AAA23238; Sat, 27 May 1995 00:09:19 -0700 Message-Id: <199505270709.AAA23238@rx7.ee.lbl.gov> To: mbone@isi.edu, rem-conf@es.net Subject: linux vat, sd & wb available on ftp.ee.lbl.gov Date: Sat, 27 May 95 00:09:17 PDT From: Van Jacobson Two weeks ago I sent a message saying we had just purchased a machine for linux development & it would probably take about two weeks to port vat, sd & wb to linux. Thanks to a lot of help from Craig Leres, it only took 9 days. We then spent 4 days trying (unsuccessfully) to fix a problem with the linux multicast code so we could offer a patch with the tools. Since the tools are usable even without fixing the kernel problem, we've decided to release them without a kernel patch. They're available in the usual place. I.e., ftp://ftp.ee.lbl.gov/conferencing/vat/linux-vat-3.5.tar.Z ftp://ftp.ee.lbl.gov/conferencing/wb/linux-wb-1.59.tar.Z ftp://ftp.ee.lbl.gov/conferencing/sd/linux-sd-1.17.tar.Z Everything has been build under the Slackware 1.2.8 distribution. The tools were all linked '-static' in the hopes of minimizing problems with different versions of various libraries. They were also all compiled "-g" so interested parties could send us gdb tracebacks with bug reports. Since -g makes the binaries huge, you might want to strip them if your system is tight on disk space. Let us know of any problems. Thanks. - Van Jacobson & Steve McCanne - ------------ This is the README.linux from vat: Notes on vat for linux. Wed May 24 08:50:53 PDT 1995 This is the first release of vat for linux. It has had very little testing so expect bugs. There are some minor problems due to the way PC audio cards work & a major problem from a missing part of the linux multicast code. The audio problems are: - Most PC audio is half-duplex (cannot play & record at the same time) so none of the 'speakerphone' or full-duplex audio modes of vat are available. Essentially you always run in "mike mutes net" mode. We have a PAS-16 on order (the one card we know of that does full duplex audio) and hope to work on full-duplex linux audio support whenever it shows up. That's probably at least a month away. - The linux audio driver doesn't include any way to set the play or record volume so the volume sliders do nothing. The major problem is the multicast code is that multicast through the loopback interface does not work. This is a very serious deficiency since local (loopback) multicast sockets are used to implement "conference busses" that vat/vic/etc. use to do things like pass the audio hardware between different vats, automatically switch video windows on audio activity, etc. We, and others, also have floor & conference control agents (for moderated meetings) and key distribution agents (for private meetings with dynamic membership control) in the works. None of these things will work on linux without fixing the linux kernel. I was hoping to come up with a patch for this but, since the loopback interface is used (wrongly, in my view) to implement the IP_MULTICAST_LOOP socket option, quite a lot of code needs to be changed & I haven't yet figured out enough of the linux socket buffer & locking/ipl conventions to make the changes. Ignoring the future tools that won't work, right now you will find that the lack of local multicast makes it *very* difficult to switch the audio between multiple instances of vat. You will probably want to run just one at a time. There is another, minor, multicast bug that doesn't allow the multicast ttl to be set to 0 (the spec specifically defines 0 as "this machine"). I think the code in linux/net/inet/ip.c should be patched as follows: diff -c -r1.1 ip.c *** 1.1 1995/05/27 06:24:35 - --- ip.c 1995/05/27 06:25:28 *************** *** 2090,2096 **** unsigned char ucval; ucval=get_fs_byte((unsigned char *)optval); ! if(ucval<1||ucval>255) return -EINVAL; sk->ip_mc_ttl=(int)ucval; return 0; - --- 2090,2096 ---- unsigned char ucval; ucval=get_fs_byte((unsigned char *)optval); ! if(ucval>255) return -EINVAL; sk->ip_mc_ttl=(int)ucval; return 0; This bug currently has little effect but will be annoying if the loopback bug is fixed. Good luck. Please send any bug reports to "vat@ee.lbl.gov". Thanks. ------- End of Forwarded Message