Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!think.com!cayman!brad From: brad@andros.cayman.com (Brad Parker) Newsgroups: comp.sys.mac.comm Subject: Re: MacTCP problem Message-ID: Date: 1 Dec 90 18:32:59 GMT References: <1990Nov30.205337.8345@ux1.cso.uiuc.edu> <693@nih-csl.nih.gov> Sender: news@cayman.COM Organization: /home/brad/.organization Lines: 30 Nntp-Posting-Host: In-reply-to: ken@helix.nih.gov's message of 1 Dec 90 02:22:00 GMT In article <693@nih-csl.nih.gov> ken@helix.nih.gov (Ken Weeks) writes: I've been using NCSA Telnet to talk to my VAX, which is running a Telnet server. I recently "converted" from the embedded TCP driver version to the Mac TCP version. No problems at first...but as of late, I've noticed a severe, repeatable "hang" when I use the VMS "TYPE" commands, or list a long directory. Just that session hangs - I can log in again and kill it I think the "mss" or maximum segment size of the TCP you are using is too large for your gateway. Under NCSA you can set it (in the config.tel file) to a small number like 512 which will not require that you gateway fragment the packets. Under MacTCP, is it not settable, and I think MacTCP 1.0 has a bug which causes it to guess wrong; (or at least guess a number which causes you to need a gateway which will fragment properly) I'll go out on a limb and guess that your mac is on localtalk and you're using a gateway to get to the ethernet. If the gateway is a fastpath, it may not support fragmentation of IP packets too big to be encapsulated in a single localtalk packet (~600 bytes); If the gateway is a gatorbox, you're software may be out of date as we used to have this problem but fixed it. If this makes no sense, send me mail and I'll explain more. -brad -- "Medea... she led Jason and Orpheus to the sacred garden which contained the fleece." Brad Parker Cayman Systems, Inc., Cambridge, Ma. brad@cayman.com