Suddenly, latency...

I have two TS MEI single port PortServers connected via “Serial Bridging”.

I backed up their configurations and was comparing them and noticed that one has the following line:

set buffers range=1 size=32 state=off

Where the other has no “set buffers…” command at all.

Any ideas what this is for and why it would only be on one of the boxes?

The buffer setting only applies to port logging which is enabled under the Advanced Serial settings >
__Enable Port Logging
Log size:

If this value is not check marked, the log size would have no bearing here.

With regards to the problem, what exactly is the behavior you are seeing? Had this been working for some time?

Some things to look at by running the following command from the root prompt:

#> info serial:1

Values showing for norun, noflow, nframe, nparity, and nbreak are indications of errors.

You also might want to check on possible network latency/bandwidth issues.