ssl is encrypting the connection to to the server, like ssl to website work. OTR is encrption between peers or clients, So lets say you are running the monitoring plugin in openfire. Even with ssl, youre able to see converstations (since the server is the endpoint and traffic passes through it). If you turn on OTR at the client, you’ll still record the converstation, but you’ll only see encrypted gibberish…because the encryption is client to client.