Problems with Sun 3/160 RS232 connections.

[Howard Weiss]

We've got a local network made up of SUN 3/160s, 3/260s, and 3/60s.  All
the 3/60s are running SUN OS 4.0 (as well as one of the 160s with the
other machines running OS 3.2).  When the 60s were delivered, they each
had 4 meg of memory (boy was 4.0 slow!), but they have since been upgraded
to 12 meg each.

We use RS232 connections to access several other machines which are not
connected to our Ethernet cable.  When the 3/60s only had 4 meg, the RS232
connections (running tip) were fine at 9600 baud - no flow control, no
parity errors, perfect communications.  After upgrading the memory, the
SUN seems unable to keep up with the other end of the 9600 baud connection
(in many cases a very old PDP 11/70).  Tandem mode takes care of most of
the problems except when running a raw mode program on the 11/70 which
ignores the XON-XOFF flow control resulting in lost characters.  This
occurs now whether using tip or kermit, although it is worse with tip.

Anyone have any ideas why this should have happened AFTER upgrading!  By
the way, when running tip or kermit from one of our 8 meg 160s, we
experience no problems.

Howard Weiss