Can telnet port 80 but cannot ping!

[taalebi at ai.mit.edu (Ali Taalebi)]

I am running RedHat Linux 7.2 on a Compaq DeskPro.
I can successfully:
	telnet <My-Host> 80

However, if I try:
	telnet <My-Host>
it responds:
	"telnet: Unable to connect to ...."

I have also tried: 
	ping <My-Host>
but it says:
	"no answer from h00045adc236a.ne.mediaone.net"

Any idea what steps I should take to make these services available 
on my server? I should mention that I chose the telnet and other
modules during my installation of of my Linux.

Many thanks in advance.
>>Ali