TCP versus UDP


TCP versus UDP

Above, we have talked about TCP and UDP as an overview. Here, we will compare these two protocols’s main characteristics. This comparison is very important and generally a question asked in a Network Engineering Technical Interview.


TCP and UDP Application Ports

Generally Port ranges can be divided into three. These are:

• Well-Known Ports ( 1 to 1024 )
• Registered Ports ( 1025 to 49151 )
• Private Ports ( 49152 to 65535 )

The applications which use TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) use Well-Known Ports. Let’s see, some of these Well-Known Ports.

TCP Well-Known Ports

There are some Applications that use TCP (Transmission Control Protocol) . Some of these Applications are :

• FTP (Port 20,21)
• SSH (Port 22)
• Telnet (Port 23)
• SMTP (Port 25)
• DNS (Port 53)
• HTTP (Port 80)
• POP3 (Port 110)
• SNMP (Port 161)
• SNMP Trap (Port 162)
• HTTPS (Port 443)



UDP Well-Known Ports

Some network services use UDP and UDP Ports. Some of these services are :

• DNS (Port 53)
• DHCP (Port 67)
• TFTP (Port 69)
• SNMP (Port 161)
• SNMP Trap (Port 162)
• RIP (Port 520)


Some these ports can be used for both Protocols as you can see.

You can find the whole list of this ports at the IANA Website.

In that list you can also see the ports of other Trasport Layer protocols, Stream Control Transmission Protocol and Datagram Congestion Control Protocol (DCCP) beside UDP and TCP.

Lesson tags: tcp, udp
Back to: HCNA > TCP and UDP