SFTP client Expect 5.43 via PASE intermittently failing

I have an SFTP client Expect 5.43 via PASE intermittently failing.
This process runs every 15 minutes, 6 am to 9 pm, Sun thru Sat, so about 60 times per day.
40 failures since 11/20, when this converted from an FTP to SFTP.

When it fails, I get this error message.

ssh_exchange_identification: read: Connection reset by peer
Connection closed

The remote side has not found any issues on their side.
We haven't found any issues on our side.

What was discovered that at the same time of some of the failures, our ISP was having DOS attacks.

My question is two-fold.
1) During the initial SFTP handshake process, how long does this normally take?
2) Could the DOS attacks be slowing down the SFTP handshake process, thus not allowing it to complete in its required time interval X, whatever X is?

Thank You
_____
Paul Steinmetz
IBM i Systems Administrator

Pencor Services, Inc.
462 Delaware Ave
Palmerton Pa 18071

610-826-9117 work
610-826-9188 fax
610-349-0913 cell
610-377-6012 home

psteinmetz@xxxxxxxxxx
http://www.pencor.com/