| IANA Categories of TCP and UDP Ports | ||
| Port Category | Port Number | Range Description |
| Well-known ports | 0–1023 | Typically used by standard system processes or programs that are executed by users with administrator credentials. Assigned by IANA. |
| Registered ports | 1024–49151 | Used by ordinary user processes or programs that are executed by ordinary users. IANA does not assign these ports, but registers use of them as a convenience for the TCP/IP community. |
| Dynamic or private ports | 49152–65535 | Unassigned and unregistered ports used for private applications, client-side processes, or other processes that dynamically allocate port numbers. |
Some of the default TCP port numbers for processes that are commonly used
| TCP Ports and Associated Services | |
| Default TCP Port Number | Internet Service |
| 20 | FTP Data Channel |
| 21 | FTP Control Channel |
| 23 | Telnet (enabled on some intranet or Internet servers) |
| 25 | Simple Mail Transfer Protocol (SMTP) |
| 80 | HTTP for World Wide Web |
| 119 | Network News Transfer Protocol (NNTP) |
| 443 | Hypertext Transfer Protocol over TLS/SSL (HTTPS) for secure World Wide Web |
| 563 | Network News Transfer Protocol over TLS/SSL (NNTPS) |
http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers
