Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!samsung!zaphod.mps.ohio-state.edu!sunybcs!sybil.cs.Buffalo.EDU!tksjmi
From: tksjmi@sybil.cs.Buffalo.EDU (JoAnn Illuzzi)
Newsgroups: comp.protocols.tcp-ip.ibmpc
Subject: 3Com ethernet problem
Message-ID: <14274@eerie.acsu.Buffalo.EDU>
Date: 6 Dec 89 13:52:24 GMT
Sender: nobody@acsu.buffalo.edu
Reply-To: tksjmi@sybil.cs.buffalo.edu (JoAnn Illuzzi)
Organization: SUNY/Buffalo Computer Science
Lines: 47


 I am having some ftp problems involving pc's using 3c501s.  I am pretty
 sure ps/2s with 3c523s are having the problem also.

 I can't get a handle on the circumstances that cause this problem. 
 I am posting 'the facts' about what happens in the hope of getting
 some feedback from this list.

 Ftps involving a pc will 'go to sleep' for several minutes, and this
 happens with files over 4k or so.  The transfer is going, but the ftp
 literally stops for a few minutes.  

 On a lanayzer, here is what seems to happen, I am including seq and
 ack numbers if they help-

    mini/mainframe			pc with 3c501

     data to pc
    seq=119062017
    ack=30347265
					   ack
					seq=30347265
					ack=119062529
     
   --- no activity for 2 minutes 43 seconds ----------------
					   ack
					seq=15114455
					ack=92480666
  --- 2 second wait here -----------------------------------
					   ack
					seq=30347265
					ack=119062529
     data to pc
   seq=119062529
   ack=30347265
 ----  normal stuff ----------

 What is causing this delay of almost 3 minutes??  I don't have this
 problem between larger machines, only when it is pc-mini/whatever,
 mini/whatever to pc.  

 I have tested mainly with NCSA telnet 2.2tn, but have the same results
 with other software packages like ka9q and ftp inc's pc/ftp.

 Any suggestions are welcome!  
 thanks
 JoAnn