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Lightweight User Datagram Protocol (UDP-Lite)

The Lightweight User Datagram Protocol (UDP-Lite) ([http://www.ietf.org/rfc/rfc3828.txt RFC 3828]), which is similar to the User Datagram Protocol (["UDP"]) ([http://www.ietf.org/rfc/rfc768.txt RFC 768]), but can also serve applications in error-prone network environments that prefer to have partially damaged payloads delivered rather than discarded. If this feature is not used, UDP-Lite is semantically identical to UDP.

History

Wireless links typically have lower bit rates and higher error rates when compared to wired links. Applications such as audio/video streaming can use error-resilient codecs, but are delay-sensitive. Hence retransmission due to checksum errors is expensive. UDP Lite has been developed for these classes of applications. People have used it for streaming media, as well as video over cellphones, with good results.

Protocol dependencies

Example traffic

{{{Frame 1 (60 bytes on wire, 60 bytes captured) Ethernet II, Src: 00:60:97:a0:e3:7e (00:60:97:a0:e3:7e), Dst: 00:04:75:c7:87:49 (00:04:75:c7:87:49) Internet Protocol, Src: 139.133.204.185 (139.133.204.185), Dst: 139.133.204.176 (139.133.204.176)

Lightweight User Datagram Protocol, Src Port: 1024 (1024), Dst Port: 1234 (1234)

Data (12 bytes)

0000 68 65 6c 6c 6f 20 77 6f 72 6c 64 0a hello world.}}}

Wireshark

The UDP-Lite dissector is available in Wireshark 0.10.14 and up. It rides with the ["UDP"] dissector, using an additional field for checksum coverage length.

Preference Settings

Example capture file

Display Filter

A complete list of UDP-Lite display filter fields can be found in the [http://www.wireshark.org/docs/dfref/protofirstletter/proto.html display filter reference]

Capture Filter

Discussion