11.2. Flow Component Definitions
11.2. Flow Component Definitions
A Flow Specification consists of a sequence of flow components, which are identified by an 8-bit component type. IANA has created and maintains a registry entitled "Flow Spec Component Types". IANA has updated the reference for this registry to RFC 8955. Furthermore, the references to the values have been updated according to the table below (Note: This document obsoletes both [RFC7674] and [RFC5575], and all references to those documents have been deleted from the registry.)
| Value | Name | Reference |
|---|---|---|
| 1 | Destination Prefix | RFC 8955 |
| 2 | Source Prefix | RFC 8955 |
| 3 | IP Protocol | RFC 8955 |
| 4 | Port | RFC 8955 |
| 5 | Destination port | RFC 8955 |
| 6 | Source port | RFC 8955 |
| 7 | ICMP type | RFC 8955 |
| 8 | ICMP code | RFC 8955 |
| 9 | TCP flags | RFC 8955 |
| 10 | Packet length | RFC 8955 |
| 11 | DSCP | RFC 8955 |
| 12 | Fragment | RFC 8955 |
Table 10: Registry: Flow Spec Component Types
In order to manage the limited number space and accommodate several usages, the following policies defined by [RFC8126] are used:
| Type Values | Policy |
|---|---|
| 0 | Reserved |
| [1 .. 127] | Specification Required |
| [128 .. 254] | Expert Review |
| 255 | Reserved |
Table 11: Flow Spec Component Types Policies
Guidance for Experts:
The registration policy for the range 128-254 is Expert Review. The experts are expected to check the clarity of purpose and use of the requested code points. The experts must also verify that any specification produced in the IETF that requests one of these code points has been made available for review by the IDR Working Group and that any specification produced outside the IETF does not conflict with work that is active or already published within the IETF. It must be pointed out that introducing new component types may break interoperability with existing implementations of this protocol.