Some of the popular applications and protocol/port numbers mapping are defined below:
Application
Protocol
Port Number
Telnet
TCP
23
FTP
TCP
21
SMTP
TCP
25
POP3
TCP
110
H.323
TCP
1720
SNMP
UCP
161
SNMP Trap
UDP
162
HTTP
TCP
80
PPTP
TCP
1723
PC Anywhere
TCP
5631
PC Anywhere
UDP
5632
31