[cs615asa] Hi professor:

[hchen29]

 > Could you provide us some advises?

Hello,
Try this trick: try to open two ssh tools (terminal on Mac or putty on 
Windows). The first one do the ssh and then do the ssh at the same time 
on the other one (there is no need to wait for the failure feedback from 
the server of the first ssh). Then you will get login on the second ssh 
tool. Most time this trick will work except for some time from 1:00am - 
3:00am.

best