| Internet-Draft | UDP APHD Example | October 2021 |
| McQuistin, et al. | Expires 28 April 2022 | [Page] |
This document describes UDP using Augmented Packet Header Diagrams. This document is an example of the Augmented Packet Header Diagram language: it is not intended as a contribution to any ongoing or future work on maintaining or extending UDP.¶
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Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.¶
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Copyright (c) 2021 IETF Trust and the persons identified as the document authors. All rights reserved.¶
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.¶
This document uses Augmented Packet Header Diagrams [AUGMENTED-DIAGRAMS] to describe UDP [RFC768], and is intended to further discussion about the design and implementation of the Augmented Packet Header Diagram language and tooling. Given this purpose, this document is not intended as a contribution to any ongoing or future work on maintaining or extending UDP. Further, this document does not necessarily reflect UDP, and its extensions, as presently standardised.¶
This document describes the UDP protocol. The UDP protocol uses UDP Headers.¶
A UDP Header is formatted as follows:¶
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Source port | Destination port | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Length | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | : : Payload : : | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+¶
where:¶
Sending port.¶
Destination port.¶
Length of the header and payload in bytes.¶
Checksum is the 16-bit one's complement of the one's complement sum of a pseudo header of information from the IP header, the UDP header, and the data, padded with zero octets at the end (if necessary) to make a multiple of two octets.¶
The payload of the UDP datagram, which is the whose size is the value of the Length field, less 8 bytes for the header.¶
This document contains no actions for IANA.¶
The security implications of the Augmented Packet Header Diagrams format are considered in [AUGMENTED-DIAGRAMS].¶
This work has received funding from the UK Engineering and Physical Sciences Research Council under grant EP/R04144X/1.¶
The source code for tooling that can be used to parse this document, and generate parser code for the protocol it describes, is available from https://github.com/glasgow-ipl/ips-protodesc-code.¶