IM Server

IM Server
The IM server maintains the directory of user accounts, keeps track of who is
online, and, in most cases, routes messages among users. The IM server operates in
real time, sending messages back and forth between two users as they finish typing
each line of text. The servers also pass real-time information about the availability
of various users in the directory, such as when they come online and change their
status message.
Each IM server communicates with its clients over an assigned port number across
the Internet. But IM clients however, can login using other ports when the default
port is blocked by a deny policy. Typical port numbers include those shown in the
following table:
IM Application Service Port Numbers Proxies
AIM 5190 SOCKS 4, SOCKS 5,
HTTP, HTTPS
ICQ 5190
YMSG 50501 (443 and 80)
1.In addition to port 5050, make sure traffic is permitted on
ports 443 (HTTPS) and 80 (HTTP).
SOCKS 4, SOCKS 5,
HTTP
MSN Messenger 1863 SOCKS 4, SOCKS 5,
HTTP