]> Huawei

Beijing China shihang9@huawei.com

Huawei

Beijing China zhoutianran@huawei.com

China Unicom

Beijing China liuy619@chinaunicom.cn

China Unicom

Beijing China hanmy12@chinaunicom.cn

Operations and Management IP Performance Measurement Congestion Measurement IPv6 The Congestion Measurement enables precise congestion control, aids in effective load balancing, and simplifies network debugging by accurately reflecting the degree of congestion across network paths. This document outlines how Congestion Measurement Data-Fields are encapsulated in IPv6. Discussion Venues Discussion of this document takes place on the IP Performance Measurement Working Group mailing list (ippm@ietf.org), which is archived at . Source for this draft and an issue tracker can be found at .

Introduction defines data fields of Congestion Measurement which enables sender to obtain the degree of congestion across the path. This document defines the IPv6 encapsulation of the Congestion Measurement Data-Fields.

Requirements Language The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 when, and only when, they appear in all capitals, as shown here.

Congestion Measurement Option One IPv6 option, Congestion Measurement Option is defined to carry the Congestion Measurement Data-Fields.

Congestion Measurement Option

where:

• Opt Type: Type value is TBD1, an 8-bit unsigned integer. Identifier of the type of this Congestion Measurement Option.
• Opt Data Len: An 8-bit unsigned integer. Length of the Option Data field of this option, that is, length of the Congestion Measurement Data-Fields.
• Congestion Measurement Data-Fields: Option-Type-specific data. It carries the data fields for Congestion Measurement as specified in .

Congestion Measurement Hop-by-hop Options Header (HBH) The Congestion Measurement option can be carried in the IPv6 Hop-by-Hop Options Header. In this case, each node along the path can inspect the Congestion Info Data field if they are configured the support this option. If the U bit of Congestion Measurement Data-Fields is set, intermediate nodes will modify the Congestion Info Data field accordingly.In theory, the presence of the Hop-by-Hop Option should not affect the traffic throughput both on nodes that do not recognize this Option and on the nodes that support it. However, in a real implementation, a packet with a Hop-by-hop Option may be skipped or processed in the slow path. Proposals to mitigate the problem are out of the scope for this document.

Congestion Measurement Destination Options Header (DOH) The Congestion Measurement option can be carried in the IPv6 Destination Options Header. In this case, it is usually processed by the destination node. Note that, if there is also a Routing Header (RH), any visited destination in the route list can process it. If the U bit of Congestion Measurement Data-Fields is set, intermediate nodes will modify the Congestion Info Data field accordingly.

Security Considerations TBD.

IANA Considerations IANA is requested to assign an IPv6 Option from the "Destination Options and Hop-by-Hop Options" subregistry of "Internet Protocol Version 6 (IPv6) Parameters" as follows:

Value	Description	Reference
TBD1	Congestion Measurement Option

References Normative References In many standards track documents several words are used to signify the requirements in the specification. These words are often capitalized. This document defines these words as they should be interpreted in IETF documents. This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements. RFC 2119 specifies common key words that may be used in protocol specifications. This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the defined special meanings. Informative References Huawei Huawei China Mobile China Mobile Congestion Measurement collects the congestion information in the packet while the packet traverses a path. The sender sets the congestion measurement command in the packet header indicating the network device along the path to update the congestion information field in the packet. When the packet arrives at the receiver, the congestion information field will reflect the degree of congestion across network path. Congestion Measurement can enable precise congestion control, aids in effective load balancing, and simplifies network debugging. This document defines data fields for Congestion Measurement. Congestion Measurement Data-Fields can be encapsulated into a variety of protocols, such as Network Service Header (NSH), Segment Routing, Generic Network Virtualization Encapsulation (Geneve), or IPv6.