I used an Adtran 5600 connected to a PM2 for a while, and switched to
synchronous as fast as I could. I am not sure why, but I noticed two
problem behaviors:
1. The connection was not stable. It would drop and reset 3-5 times per
day. Granted, it cycled fairly quickly, but it was noticeable and 56K
lines aren't supposed to do that, AFAIK.
2. More seriously, the connection performance seemed to deterioriate down
to extremely poor throughput, and then slowly speed up and then slow
dowwn. It was at the troughs that the connection would break if it was
going to.
So, even though synchronous ports cost *A LOT* more than async ports, I
moved my connection to a sync port and it is much faster and hasn't
dropped in 30 days.
Darren Ellis
darren@wordwrap.net / darren@cybernexus.net
Internet/WAN Technician