Internet-Draft Wi-Fi-Quality-Info July 2026
Grayson & Redmore Expires 7 January 2027 [Page]
Workgroup:
RADEXT Working Group
Internet-Draft:
draft-grayson-radext-wba-wifi-quality-metrics-00
Published:
Intended Status:
Informational
Expires:
Authors:
M. Grayson
Cisco Systems
J. Redmore
CableLabs

RADIUS WBA Vendor-Specific Attributes for Wi-Fi Network Quality Metric Reporting

Abstract

This document defines a set of RADIUS Vendor-Specific Attributes (VSAs) designed to encode network quality metrics that are not uniquely associated with an IEEE 802.11 (Wi-Fi) connection. These attributes enable access network quality information to be communicated between RADIUS clients and servers.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

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/.

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on 7 January 2027.

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Table of Contents

1. Introduction

The RADIUS Connect-Info attribute is defined in [RFC2869] to enable a Network Access Server (NAS) to indicate to a RADIUS server "the nature of the user's connection". [I-D.draft-grayson-connectinfo] defines a syntax for the Connect-Info attribute, enabling RADIUS clients to provide RADIUS servers information pertaining to a user's connection with an IEEE 802.11 wireless network. Reception of the Connect-Info attribute by a RADIUS server is intended to be used to assist the operator of the RADIUS server in making authorization decisions.

There are use cases that benefit from sharing generic quality metric information not uniquely associated with an IEEE 802.11 Wi-Fi connection. Similar to the RADIUS Connect-Info attribute, this information is intended to assist the RADIUS server operator in making authorization decisions.

This document defines a set of RADIUS Vendor Specific Attributes (VSAs) for encoding the non-802.11-connection metrics.

The technique by which a server uses the information encoded in these attributes to assist in making authorization decisions is not defined in this document.

1.1. 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 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

2. Wi-Fi Quality Metrics

The following metrics are defined as being not uniquely associated with the specifics of an 802.11 connection:

These attributes encode values that do not describe the properties of a specific association between a client and a Wi-Fi access point, but rather general access network characteristics. Wi-Fi access points supporting these attributes SHOULD use measurements associated with multiple Wi-Fi devices, potentially across multiple WLANs, when calculating these metrics as described in the individual attributes.

These attributes MAY be sent in both Access-Request and Accounting-Request messages, as shown in Figure 1.

+-------------------------------------------------------------------+
| Attribute      | Request | Accept | Reject | Challenge | Acct-Req |
+-------------------------------------------------------------------+
| Quality-Metric |   0+    |   0    |   0    |     0     |    0+    |
+-------------------------------------------------------------------+
Figure 1: Occurrence rules for Quality Metric attribute

3. Quality-Metric Attribute Definitions

Each Quality-Metric is encoded as a separate VSA as defined in section 5.26 of [RFC2865] using the Vendor-ID 14122 for the Wireless Broadband Alliance, Inc. The metrics are encoded using complex-data types, as described in section 3.2.3 of [RFC6158].

While section 3.2.4 of [RFC6158] generally discourages the use of complex data types when viable alternatives exist, this document adopts them to maintain logical cohesion between the reported metric, the calculation algorithm, and the associated algorithm parameters. This approach avoids the proliferation of fragmented, atomic VSAs that would otherwise be required to represent these metrics. By encapsulating related fields within a single VSA, this design reduces complexity in non-RADIUS systems and avoids the operational awkwardness of requiring multiple, loosely-coupled attributes to convey a single, unified measurement.

This usage is consistent with the provision in section 2.1 of [RFC6158] that states that complex data types may be employed where they reduce complexity or where basic data types would necessitate cumbersome grouping mechanisms.

3.1. WAN Round Trip Time

The WAN Round Trip Time (RTT) can be measured by the Wi-Fi infrastructure using a well-known anycast IP address, e.g., linked to a DNS service, that automatically routes to the closest destination.

In all cases of signalling WAN-RTT, the NAS SHOULD use multiple measurements when calculating the reported value according to the Algorithm and Algorithm-Parameter.

Where the Wi-Fi access points supports multiple WLANs that operate using different policy based routing decisions, the WAN-RTT metric SHOULD only correspond to the WLAN associated with the RADIUS session.

3.1.1. WBA-WAN-RTT Attribute 

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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|      Type     |     Length    |       Vendor-ID = 14122
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    Vendor-ID = 14122 (cont)    | sub-type (100)|   Sub-Length  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|           Algorithm           |      Algorithm-Parameter      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                            WAN-RTT                            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: WBA-WAN-RTT Attribute

Algorithm:

An unsigned 16 bit value encoding the algorithm used to calculate the WAN-RTT parameter:

    • 1 - Maximum round-trip time

    • 2 - Minimum round-trip time

    • 3 - Median round-trip time

    • 4 - Linear-Average round-trip time

    • 5 - Exponential-Average round-trip time

Algorithm-Parameter:

    • An unsigned 16 bit value. When algorithm is 1, 2, 3, or 4, the value represents the time window duration in seconds. When algorithm is 5, the high byte (bits 8-15) represents the Sample Period in milliseconds, and the low byte (bits 0-7) represents the weight of the exponential moving average, where the exponential weight is 2^n (n being the value of the low byte).

WAN-RTT:

    • An unsigned 32 bit value representing the calculated Wide Area Network Round Trip Time in milliseconds.

3.2. Channel Utilization

Used to signal the percentage of time an access point considers the channel busy due to IEEE 802.11 traffic.

In all cases of signalling Channel-Utilization, the NAS SHOULD use multiple measurements when calculating the reported value according to the Algorithm and Algorithm-Parameter.

Where the Wi-Fi access point supports multiple WLANs that operate using different bands and/or radios, the reported Channel-Utilization MUST only correspond to the channel utilization associated with the signaled band/radio.

3.2.1. WBA-Chan-Util Attribute 

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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|      Type     |     Length    |       Vendor-ID = 14122
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    Vendor-ID = 14122 (cont)    | sub-type (101)|   Sub-Length  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|           Algorithm           |      Algorithm-Parameter      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     Band      |     Radio     |      Channel-Utilization      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: WBA-Chan-Util Attribute

Algorithm:

An unsigned 16 bit value encoding the algorithm used to calculate the Channel-Utilization parameter:

    • 1 - Maximum Channel Utilization

    • 2 - Minimum Channel Utilization

    • 3 - Median Channel Utilization

    • 4 - Linear-Average Channel Utilization

    • 5 - Exponential-Average Channel Utilization

Algorithm-Parameter:

    • An unsigned 16 bit value. When algorithm is 1, 2, 3, or 4, the value represents the time window duration in seconds. When algorithm is 5, the high byte (bits 8-15) represents the Sample Period in milliseconds, and the low byte (bits 0-7) represents the weight of the exponential moving average, where the exponential weight is 2^n (n being the value of the low byte).

Band:

An 8-bit unsigned integer representing the Wi-Fi band:

    • 1 - 2.4 GHz Band

    • 2 - 5 GHz Band

    • 3 - 6 GHz Band

Radio:

    • An 8-bit unsigned integer representing a radio instance that allows a report to distinguish between an access point with multiple radios operating using common band.

Channel-Utilization:

    • A 16-bit unsigned integer representing the calculated channel utilization percentage (0-100).

3.3. Noise

Used to signal the noise level in dBm as reported by the radio survey data from the access point.

In all cases of signalling Noise, the NAS SHOULD use multiple measurements when calculating the reported value according to the Algorithm and Algorithm-Parameter.

Where the Wi-Fi access point supports multiple WLANs that operate using different bands and/or radios, the reported noise MUST only correspond to the noise level associated with the signaled band/radio.

3.3.1. WBA-Noise Attribute 

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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|      Type     |     Length    |       Vendor-ID = 14122
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    Vendor-ID = 14122 (cont)    | sub-type (102)|   Sub-Length  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|           Algorithm           |      Algorithm-Parameter      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     Band      |     Radio     |             Noise             |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: WBA-Noise Attribute

Algorithm:

An unsigned 16 bit value encoding the algorithm used to calculate the Noise parameter:

    • 1 - Maximum Noise

    • 2 - Minimum Noise

    • 3 - Median Noise

    • 4 - Linear-Average Noise

    • 5 - Exponential-Average Noise

Algorithm-Parameter:

    • An unsigned 16 bit value. When algorithm is 1, 2, 3, or 4, the value represents the time window duration in seconds. When algorithm is 5, the high byte (bits 8-15) represents the Sample Period in milliseconds, and the low byte (bits 0-7) represents the weight of the exponential moving average, where the exponential weight is 2^n (n being the value of the low byte).

Band:

An 8-bit unsigned integer representing the Wi-Fi band:

    • 1 - 2.4 GHz Band

    • 2 - 5 GHz Band

    • 3 - 6 GHz Band

Radio:

    • An 8-bit unsigned integer representing a radio instance that allows a report to distinguish between an access point with multiple radios operating on using common band.

Noise:

    • A 16-bit signed integer, representing the calculated noise value in dBm.

3.4. Station Count

Used to report the number of Wi-Fi Stations associated with a WLAN Radio.

In all cases of Station-Count, the NAS SHOULD use multiple measurements when calculating the reported value according to the Algorithm and Algorithm-Parameter.

3.4.1. WBA-STA-Count Attribute 

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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|      Type     |     Length    |       Vendor-ID = 14122
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    Vendor-ID = 14122 (cont)    | sub-type (103)|   Sub-Length  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|           Algorithm           |      Algorithm-Parameter      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     Band      |     Radio     |         Station-Count         |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: WBA-Station-Count Attribute

Algorithm:

An unsigned 16 bit value encoding the algorithm used to calculate the Station-Count parameter:

    • 1 - Maximum Station Count

    • 2 - Minimum Station Count

    • 3 - Median Station Count

    • 4 - Linear-Average Station Count

Algorithm-Parameter:

    • An unsigned 16 bit value representing the time window duration in seconds.

Band:

An 8-bit unsigned integer representing the Wi-Fi band:

    • 1 - 2.4 GHz Band

    • 2 - 5 GHz Band

    • 3 - 6 GHz Band

Radio:

    • An 8-bit unsigned integer representing a radio instance that allows a report to distinguish between an access point with multiple radios operating on using common band.

Station-Count:

    • A 16-bit unsigned integer representing the calculated station count.

3.5. Minimum RSSI

An Wi-Fi access point configuration parameter representing the minimum RSSI level for a device to associate/authenticate to the access point.

3.5.1. WBA-Min-RSSI Attribute 

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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|      Type     |     Length    |       Vendor-ID = 14122
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    Vendor-ID = 14122 (cont)    | sub-type (104)|   Sub-Length  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     Band      |     Radio     |            Min-RSSI           |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: WBA-Min-RSSI Attribute

Band:

An 8-bit unsigned integer representing the Wi-Fi band:

    • 0 - Identical for all bands

    • 1 - 2.4 GHz Band

    • 2 - 5 GHz Band

    • 3 - 6 GHz Band

Radio:

    • An 8-bit unsigned integer representing a radio instance that allows a report to distinguish between an access point with multiple radios operating on using common band.

Min-RSSI:

    • A 16-bit signed integer representing the configured value of RSSI-min in dBm.

3.6. WBA-Wi-Fi-Global-OC

Used to signal a Global Operating Class which in turn encodes band and channel bandwidth information.

3.6.1. WBA-Wi-Fi-Global-OC Attribute 

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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|      Type     |     Length    |       Vendor-ID = 14122
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
    Vendor-ID = 14122 (cont)    | sub-type (105)|   Sub-Length  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  Supported-OC |  Supported-OC |  Supported-OC |      ...      |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7: WBA-Wi-Fi-Global-OC Attribute

Supported-OC:

    • An 8 bit unsigned integer representing a supported operating class broadcast by the AP, as defined in [IEEE80211] Annex E.

4. Encoding

All multi-byte integer fields defined in this document are encoded in network byte order (Big-Endian).

Where the NAS is using the RADIUS Connect-Info attribute to report information pertaining to a user's connection with an IEEE 802.11 wireless network, a NAS supporting a particular sub-type that includes the definition of Band/Radio sub-attribute, SHOULD report the sub-type value associated with the Band(s) and/or Radio(s) associated with the user's connection. The NAS MAY optionally report sub-type values associated with other Band(s) and/or Radio(s) not associated with the user's connection.

5. Security Considerations

This document describes a set of vendor specific attributes that enables a RADIUS client to provide a RADIUS server quality metric information pertaining to the operation of an IEEE 802.11 wireless network. The terms agreed between the operator of the RADIUS client and the operator of the RADIUS server SHOULD include restrictions on the use of such non-personal information by the operator of the RADIUS server, for example limiting the use of such information to making RADIUS server authorization decisions and prohibiting a RADIUS server from disclosing information signalled to any third-party.

6. IANA Considerations

This document has no IANA Actions.

7. References

7.1. Normative References

[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/rfc/rfc2119>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/rfc/rfc8174>.

7.2. Informative References

[I-D.draft-grayson-connectinfo]
Grayson, M. and J. Redmore, "A syntax for the RADIUS Connect-Info attribute used in Wi-Fi networks", Work in Progress, Internet-Draft, draft-grayson-connectinfo-10, , <https://datatracker.ietf.org/doc/html/draft-grayson-connectinfo-10>.
[IEEE80211]
IEEE, "Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications", n.d., <https://standards.ieee.org/ieee/802.11/5536/>.
[RFC2865]
Rigney, C., Willens, S., Rubens, A., and W. Simpson, "Remote Authentication Dial In User Service (RADIUS)", RFC 2865, DOI 10.17487/RFC2865, , <https://www.rfc-editor.org/rfc/rfc2865>.
[RFC2869]
Rigney, C., Willats, W., and P. Calhoun, "RADIUS Extensions", RFC 2869, DOI 10.17487/RFC2869, , <https://www.rfc-editor.org/rfc/rfc2869>.
[RFC6158]
DeKok, A., Ed. and G. Weber, "RADIUS Design Guidelines", BCP 158, RFC 6158, DOI 10.17487/RFC6158, , <https://www.rfc-editor.org/rfc/rfc6158>.
[WBAANM]
Wireless Broadband Alliance, "Access Network Metrics - Leveraging Key Indicators to Quantify Network Performance", , <https://wballiance.com/wp-content/uploads/2024/08/Access-Network-Metrics-Whitepaper-Outline-v1.0.0-Public.pdf>.

Acknowledgements

The definition of network quality metrics has been inspired by WBA's deliverable on Access Network Metrics [WBAANM]. The authors would like to thank all the members of the WBA's Access Network Metrics project team who have helped review and refine this document.

Contributors

Sri Gundavelli
Cisco Systems
170 West Tasman Drive
San Jose, 95134
United States of America
Bruno Tomas
Wireless Broadband Alliance
5000 Executive Parkway, Suite 302
San Ramon, 94583
United States of America
Michael Sym
Single Digits
4 Bedford Farms Drive, Suite 210
Bedford, 1608
United States of America
Blair Bullock
Boldyn Networks
Pleasanton,
United States of America
Joey Padden
Helium
Boulder,
United States of America

Authors' Addresses

Mark Grayson
Cisco Systems
10 New Square Park
Feltham
TW14 8HA
United Kingdom
Joshua Redmore
CableLabs
858 Coal Creek Cr.
Louisville, 80027
United States of America