I can telnet into a linux CentOs system but caot ssh into it. My colleagues say they can ssh into it

My company has a server (server A) in a data center belonging to a telecoms company. The server has no access from the inteet. I need to access this server because of a server application that I am working on.

We have a second server (server B) in the same data center that I can easily ssh into and my colleagues say they can both ssh and telnet into (server A) from this second server.

I can also telnet (server A) from (server B), but I caot ssh into (server A) from (server B). I have no way of verifying what my colleagues are saying, but

1. Is it possible that they are saying the truth?
2. How do I ssh into a server that I can telnet to?

Thanks!