NB1 User Guide
YML780 Rev1
46
www.netcomm.com.au
The reason for this is that when using NAT, your publicly accessible IP address will
be used by and point to your router, which then needs to deliver all traffic to the
private IP addresses used by your PCs.
The Internet Assigned Numbers Authority (IANA) is the central coordinator for the
assignment of unique parameter values for Internet protocols. Port numbers range
from 0 to 65535, but only ports numbers 0 to 1023 are reserved for privileged serv-
ices and are designated as “well-known ports”. The registered ports are numbered
from 1024 through 49151. The remaining ports, referred to as dynamic ports or
private ports, are numbered from 49152 through 65535.
Examples of well-known and registered port numbers are shown in Table 4, for fur-
ther information, please see IANA’s website at: http://www.iana.org/assignments/
port-numbers
Well-know and registered Ports
Port Number
Protocol
Description
20
TCP
FTP Data
21
TCP
FTP Control
22
TCP & UDP
SSH Remote Login Protocol
23
TCP
Telnet
25
TCP
SMTP (Simple Mail Transfer Protocol)
53
TCP & UDP
DNS (Domain Name Server)
69
UDP
TFTP (Trivial File Transfer Protocol)
80
TCP
World Wide Web HTTP
110
TCP
POP3 (Post Office Protocol Version 3)
119
TCP
NEWS (Network News Transfer Protocol)
123
UDP
NTP (Network Time Protocol)
161
TCP
SNMP
443
TCP & UDP
HTTPS
1503
TCP
T.120
1720
TCP
H.323
4000
TCP
ICQ
7070
UDP
RealAudio