Transport layer protocols
The transport layer protocols include TCP and UDP used to transport application protocols.
User Datagram Protocol
The User Datagram Protocol (UDP) is considered an unreliable transport. In this, there's no guarantee of packet delivery or ordering, but it has a lower overhead and is used by time-sensitive applications such as voice and video traffic.
The following screenshot shows the fields contained in an UDP header:
The UDP header is only 8-bytes long, consisting of:
- Source and Destination port number: This is 2 bytes each.
- Length: This is the length of the UDP header plus the payload. This is a 2-byte field.
- Checksum: This is a 2-byte field used to check for errors in the UDP header and data. If no checksum was generated by the transmitter, this will be all zeroes.
Wireshark UDP filters
Capture
filter(s): udp udp port 2222
Display filter(s): udp udp.srcport == 161 (SNMP response) udp.length > 256
Transmission Control Protocol
The Transmission Control...
