For what OXE release? As I understand - from R7 (or 7.1) telnet disabled by default. And you need enable (ippstat command, item 21 Enable telnet service for GD/GA).
As far as i am aware you can only telnet to the GD - if you disable telnet or activate security on the OXE (ie enable SSH) you've lost all hope of connecting to the GD again unless you physically go to site and enable it again (from the GD)! Sucks!
We don't see things the way they are; we see things the way we are!