Date: Fri, 28 Jan 94 04:30:02 PST From: Advanced Amateur Radio Networking Group Errors-To: TCP-Group-Errors@UCSD.Edu Reply-To: TCP-Group@UCSD.Edu Precedence: Bulk Subject: TCP-Group Digest V94 #25 To: tcp-group-digest TCP-Group Digest Fri, 28 Jan 94 Volume 94 : Issue 25 Today's Topics: GPIB and packet jnos gateway MTU, TCP MSS, TCP WIN New NET/Mac (hamradio TCP/IP) for the Macintosh TPC MSS and TCP WIN per port Send Replies or notes for publication to: . Subscription requests to . Problems you can't solve otherwise to brian@ucsd.edu. Archives of past issues of the TCP-Group Digest are available (by FTP only) from UCSD.Edu in directory "mailarchives". We trust that readers are intelligent enough to realize that all text herein consists of personal comments and does not represent the official policies or positions of any party. Your mileage may vary. So there. ---------------------------------------------------------------------- Date: Thu, 27 Jan 94 16:33:29 CST From: garnier@sol.med.ge.com (Dave Garnier x7-4286) Subject: GPIB and packet To: tcp-group@ucsd.edu *>FYI - *> *>The Circuit Cellar BBS has a parallel to GPIB adapter info and SW *> *>GPIBLPT.ZIP *I tried to look for it with archie but could not find any references. *Could you put it somewhere where I could ftp this file from. Could some kind soul post the fone number to this group? Thanks much! dave garnier wb9own ge medical systems, milwaukee garnier@sol.med.ge.com ------------------------------ Date: Thu, 27 Jan 1994 08:22:14 -0500 From: Gary Skuse Subject: jnos gateway To: TCP-Group@UCSD.Edu I am running jnos on a dos box which is connected to a landline by a serial port and to our University's extended LAN via an ethernet connection. I would like to set up a gateway between the two so that I can call in by telephone and get out over the Internet. I can figure out how to telnet but I can't ftp. Has anyone done this? I would appreciate any suggestions anyone has to offer. Eventually I would like to do something similar at home so that I can access my ethernet network at home via the telephone from work. tnx and 73, ka1njl ------------------------------ Date: Thu, 27 Jan 1994 10:31:25 -0800 (PST) From: uswnvg!tconboy@uunet.UU.NET (Terry A. Conboy) Subject: MTU, TCP MSS, TCP WIN To: uunet!ucsd.edu!tcp-group@uunet.UU.NET It seems that there is a minor confusion about these parameters. My (probably meager) understanding is that your MTU determines the biggest datagram that you send (allowing for 40 bytes of TCP/IP overhead) and that MSS and WIN control what is sent TO you. In other words, if you are sending mail or files to another host, your MSS and WIN have no effect on what you send out to them. I have a PC with a 1200 bps KISS TNC and a 2400 bps SLIP link. I set the MTU on the TNC to 296 since the radio path is sometimes marginal to some stations I communicate with. I set the MTU on the SLIP to 1064 to allow big datagrams to be sent to my computer at work over a 2400 bps dialup. I set TCP MSS to 1024 and TCP WIN to 2048 to allow up to 2 datagrams to be outstanding without an ACK. This works well in practice, since the congestion window (Cwind) typically gets adjusted down to the MTU-40 of the station at the other end of the radio link very quickly. So for me, having MSS or WIN per port isn't very important. However, it does require that the station at the other end of a radio link be intelligent in setting his MTU on the radio port. I've gleaned this from reading the docs, watching lots of traces, and looking at the 'socket nnn' displays. If there's a flaw in my reasoning, let me know. 73, Terry -- Terry Conboy email: tconboy@uswnvg.com U S WEST NewVector Group packet: n6ry@n7ipb.wa.usa 3350 - 161st Ave SE, MS 571 office: (206) 450-8388 Bellevue, WA 98008 fax: (206) 450-8399 ------------------------------ Date: Thu, 27 Jan 1994 10:13:03 +0100 From: adam@igg.tno.nl (Adam van Gaalen PA2AGA) Subject: New NET/Mac (hamradio TCP/IP) for the Macintosh To: ham-digital@ucsd.edu, tcp-group@ucsd.edu The Netherlands, January 25, 1994. Hello dear reader, Today I distributed the file NET_Mac2.3.35.sea.hqx... In this version of NET/Mac I implemented the following: - New parameter for 'perform' command - New: 'reboot_on_bad_date' } These new commands were implemen- - New: 'sourcewhendone' } ted to make it easier to maintain - New: 'resetsmtpto' } an unattended slip-telephone-link - Improved the generation of dynamic aliases - Some more 'enhancements' for q-and-d AppleTalk-fix - Some more 'enhancements' for q-and-d fix This version obsoletes all versions of info-mac/comm/radio-netmac in the Sumex-Aim archives. The new NET/Mac has been uploaded to ucsd.edu, to the directory /hamradio/packet/tcpip/incoming. If it's not there (anymore), then look at /hamradio/packet/tcpip/mac. Kind regards, Adam PA2AGA (e-mail: adam@igg.tno.nl ) ( or: pa2aga@igg.tno.nl for letters only, NO BIG files here) ------------------------------ Date: Thu, 27 Jan 94 07:04:23 CST From: Jack Snodgrass Subject: TPC MSS and TCP WIN per port To: tcp-group mailling list Someone posted a message or sent me a note saying that they had fixed JNOS to allow a MSS and WINDOW value to be asinged to each port. I forgot who it was, but they said that they'd post the changes this week. I'm anxios to see the code. I've tried setting the MTU on the port to less than the TCP MSS and I'm not happy with the results. Stuff seems to go smoother when I just reduce the MSS for the entire system rather than reducing the MTU for a single port. I see packets being broken up into mtu size pieces but NOS doesn't seem to re-assemble them and acknowledge them all the time. I'm not familiar enough with the process to figure out what's wrong, but I did see the same group of MTU sized packets be sent several times and never ack'd by the receiving system. Anyway... I'd like to mod the code to use a MSS and WINDOW based on the port. At least in my enviornment, stuff does not change from port to port so that should not cause a problem. Thanks. 73's de Jack - kf5mg Internet - kf5mg@kf5mg.ampr.org - 44.28.0.14 AX25net - kf5mg@kf5mg.#dfw.tx.usa.noam - home (817) 488-4386 Dialup - kf5mg@tcet.unt.edu - work (looking for) ------------------------------ End of TCP-Group Digest V94 #25 ******************************