AT&T Labs

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This memo describes the registries for OWAMP - the One-Way Active Measurement Protocol. The registries allow assignment of MODE bit positions and OWAMP Command numbers. The memo also requests that IANA establish the registries for new features, called the OWAMP-Modes registry and the OWAMP Control Command Number registry. This memo updates RFC 4656. The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.

The One-way Active Measurement Protocol, OWAMP was prepared to support measurements of metrics specified by the IP Performance Metrics (IPPM) working group in the IETF. The Two-Way Active Measurement Protocol, TWAMP is an extension of OWAMP. The TWAMP specification gathered wide review as it approached completion, and the by-products were several recommendations for new features in TWAMP. As a result, a registry of new features was established for TWAMP. However, there were no new features proposed for OWAMP until recently . This memo establishes the needed registries for OWAMP, and updates .

The purpose and scope of this memo is to describe and request the establishment of registries for future OWAMP extensions. IANA already administrates the "Two-way Active Measurement Protocol (TWAMP) Parameters", and this request follows a similar form (with one exception identified below). This memo also provides the initial contents for the OWAMP registries.

OWAMP-Control protocol coordinates the measurement capability. All OWAMP-Control messages follow specifications defined in section 3 of .

IANA is requested to create a OWAMP-Control Command Number registry. OWAMP-Control Commands follow specifications defined in section 3.4 of .

OWAMP-Control Commands Numbers are specified in the first octet of OWAMP-Control-Client command messages consistent with section 3 of . There are a maximum of 256 command numbers.

Because the "OWAMP-Control Command Numbers" registry can contain only 256 values, and because OWAMP is an IETF protocol, these registries MUST be updated only by "IETF Consensus" as specified in (an RFC that documents registry use and is approved by the IESG).

One experimental value is currently assigned in the Command Numbers Registry, as indicated in the initial contents below.

OWAMP-Control Commands follows the procedure defined in section 3.5 of (and in the remainder of section 3). The complete set of OWAMP-Control Command Numbers are as follows (including two reserved values):

IANA is requested to create an OWAMP-Modes registry.

OWAMP-Modes are specified in OWAMP Server Greeting messages and Set-up Response messages consistent with section 3.1 of . Modes are currently indicated by setting single bits in the 32-bit Modes Field. However, more complex encoding may be used in the future.

Because the "OWAMP-Modes" are based on only 32 bit positions with each position conveying a unique feature, and because OWAMP is an IETF protocol, these registries MUST be updated only by "IETF Consensus" as specified in (an RFC that documents registry use and is approved by the IESG). IANA SHOULD allocate monotonically increasing bit positions when requested.

No experimental bit positions are currently assigned in the Modes Registry, as indicated in the initial contents below.

OWAMP-Control connection establishment follows the procedure defined in section 3.1 of . In the OWAMP-Modes registry, assignments are straightforward on the basis of bit positions, and there are no references to values - this is a difference from the comparable TWAMP registry (and a topic for improvement in the TWAMP-Modes registry which is reconciled in ). An Extension of the OWAMP-Modes is proposed in . With this extension, the complete set of OWAMP Mode bit positions are as follows (including one reserved bit position):

(where RFC_TBD the published version of draft-ietf-ippm-ipsec)

In the original OWAMP Modes field, setting bit position 0, 1 or 2 indicated the security mode of the Control protocol, and the Test protocol inherited the same mode (see section 4 of ). The value of the Modes Field sent by the Server in the Server-Greeting message is the bit-wise OR of the modes (bit positions) that it is willing to support during this session. Thus, the five least significant bits of the Modes 32-bit Field are used. When no other features are activated, the 27 most significant bits MUST be zero. A Control-Client conforming to MAY ignore the values in the 29 most significant bits of the Modes Field, or it MAY support features that are communicated in other bit positions, such as the IKEv2-derived Shared Secret Key extension . OWAMP and TWAMP registries for Modes may grow to contain different features and functions due to the inherent differences in one-way and two-way measurement configurations and the metrics they measure. No attempt will be made to coordinate them unnecessarily, except the Reserved bit position 3 above. This is available for assignment if a mixed security mode similar to is defined for OWAMP, and would allow alignment with the comparable TWAMP feature.

As this memo simply requests the creation of OWAMP registries, it presents no new security or privacy issues for the Internet. The security considerations that apply to any active measurement of live networks are relevant here as well. See and . Privacy considerations for measurement systems, particularly when Internet users participate in the tests in some way, are described in .

The author would like to thank Kostas Pentikousis, Nalini Elkins, Mike Ackermann, and Greg Mirsky for insightful reviews and comments. Spencer Dawkins caught the last of the small errors (hopefully) in his AD review.