From:	MERC::"uunet!CRVAX.SRI.COM!RELAY-INFO-VAX"  2-DEC-1992 06:22:47.71
To:	INFO-VAX <INFO-VAX@KL.SRI.COM>
CC:	
Subj:	RE: lat session limit for circuits?

Hi,
 
It a while since I answered anything here, so...
 
Richard Ault <ault@edu.queens> wrote:
 
>I have a VAX that is acting as a 48-port terminal server while I wait for my
>network wiring to get done.  As long as no more than 16 users try to set
>host /LAT to the same node, everything is fine, but when the 17th user tries to
>set host /LAT to that node, s/he gets a:
>
>LAT-F-VCSESLIM session limit for LAT circuit exceeded
>
>message.  I've checked that neither node has session limits set and both allow
>more than 16 sessions as long as there are no more than 16 sessions between the
>same two nodes.  I'm running V5.5-2 on both nodes and the new LATmasher sw.
>
>I've got a nasty feeling that the LAT protocol has a 4-bit address in it some
>where and that LAT servers do something clever to avoid the problem.  Am I
>missing somthing?  Is there anything I can do to get more than 16 set host /LAT
>sessions between the same two nodes (without buying another E-net interface)? 
 
Jerry answered with an interesting hypothesis concerned with the capacity of
virtual circuits, which is actually nothing to do with the problem.
 
There is an undocumented qualifier to the LATCP SET NODE command:
 
        SET NODE /FORWARD_SESSION_LIMIT=n.
        
where "n" is the maximum allow number of sessions on an outgoing circuit from
a node. "n" may be between 16 (the default) and 255. The default value is what
is holding you back. SET NODE is implemented through an undocumented interface
($QIO SETMODE with item lists) that may change at any time.
 
I trust this answers your question.
 
Nick (who now mainly uses Compuserve VAXFORUM)