I access to my server via Telnet

I use server Unix with AIX 5.2.

I can't telnet to server about 5 mn, then i can access to server via telnet.

This problem have again and again. Sometime can, sometime can't.

I dont know why?

Do you have any idea?

What errors do you get?

Have you run a continuous ping to see if your network is the issue here?

I dont get any errors, and about network i can ping to my server

This is just a guess, but is the TMOUT env. variable set? ( echo $TMOUT ).