Network Working Group J. Korhonen, Ed.
Request for Comments: 5624 H. Tschofenig
Category: Standards Track Nokia Siemens Networks
E. Davies
Folly Consulting
August 2009
Quality of Service Parameters for Usage with Diameter
Abstract
This document defines a number of Quality of Service (QoS) parameters
that can be reused for conveying QoS information within Diameter.
The defined QoS information includes data traffic parameters for
describing a token bucket filter, a bandwidth parameter, and a per-
hop behavior class object.
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (c) 2009 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 in effect on the date of
publication of this document (http://trustee.ietf.org/license-info).
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document.
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RFC 5624 QoS Parameters August 2009
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology and Abbreviations . . . . . . . . . . . . . . . . 3
3. QoS Parameter Encoding . . . . . . . . . . . . . . . . . . . . 4
3.1. TMOD-1 AVP . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1.1. Token-Rate AVP . . . . . . . . . . . . . . . . . . . . 4
3.1.2. Bucket-Depth AVP . . . . . . . . . . . . . . . . . . . 4
3.1.3. Peak-Traffic-Rate AVP . . . . . . . . . . . . . . . . 4
3.1.4. Minimum-Policed-Unit AVP . . . . . . . . . . . . . . . 4
3.1.5. Maximum-Packet-Size AVP . . . . . . . . . . . . . . . 4
3.2. TMOD-2 AVP . . . . . . . . . . . . . . . . . . . . . . . . 4
3.3. Bandwidth AVP . . . . . . . . . . . . . . . . . . . . . . 5
3.4. PHB-Class AVP . . . . . . . . . . . . . . . . . . . . . . 5
3.4.1. Case 1: Single PHB . . . . . . . . . . . . . . . . . . 5
3.4.2. Case 2: Set of PHBs . . . . . . . . . . . . . . . . . 5
3.4.3. Case 3: Experimental or Local Use PHBs . . . . . . . . 6
4. Extensibility . . . . . . . . . . . . . . . . . . . . . . . . 6
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
6. Security Considerations . . . . . . . . . . . . . . . . . . . 8
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 8
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9
8.1. Normative References . . . . . . . . . . . . . . . . . . . 9
8.2. Informative References . . . . . . . . . . . . . . . . . . 9
Appendix A. ABNF Code Fragment . . . . . . . . . . . . . . . . . 11
1. Introduction
This document defines a number of Quality of Service (QoS) parameters
that can be reused for conveying QoS information within the Diameter
protocol [RFC 3588]. The current set of QoS parameters defined in
this document are a core subset determined to be useful for a wide
range of applications. Additional parameters may be defined in
future documents as the need arises and are for future study. The
parameters are defined as Diameter-encoded Attribute Value Pairs
(AVPs), which are described using a modified version of the Augmented
Backus-Naur Form (ABNF), see [RFC 3588]. The data types are also
taken from [RFC 3588].
The traffic model (TMOD) AVPs are containers consisting of four AVPs
and provide a way to describe the traffic source.
o token rate (r)
o bucket depth (b)
o peak traffic rate (p)
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o minimum policed unit (m)
o maximum packet size (M)
The encoding of the <TMOD-1> and the <TMOD-2> AVPs can be found in
Sections 3.1 and 3.2. The semantics of these two AVPs are described
in Section 3.1 of [RFC 2210] and in Section 3.6 of [RFC 2215].
The <TMOD-2> AVP is, for example, needed by some DiffServ
applications.
It is typically assumed that DiffServ expedited forwarding (EF)
traffic is shaped at the ingress by a single-rate token bucket.
Therefore, a single TMOD parameter is sufficient to signal
DiffServ EF traffic. However, for DiffServ assured forwarding
(AF) traffic, two sets of token bucket parameters are needed: one
token bucket for the average traffic and one token bucket for the
burst traffic. [RFC 2697] defines a Single Rate Three Color Marker
(srTCM), which meters a traffic stream and marks its packets
according to three traffic parameters -- Committed Information
Rate (CIR), Committed Burst Size (CBS), and Excess Burst Size
(EBS) -- to be either green, yellow, or red. A packet is marked
green if it does not exceed the CBS, yellow if it does exceed the
CBS but not the EBS, and red otherwise. [RFC 2697] defines
specific procedures using two token buckets that run at the same
rate. Therefore, two TMOD AVPs are sufficient to distinguish
among three levels of drop precedence. An example is also
described in the appendix of [RFC 2597].
Resource reservations might refer to a packet processor with a
particular DiffServ per-hop behavior (PHB) (using the <PHB-Class>
AVP). A generic description of the DiffServ architecture can be
found in [RFC 2475], and the Differentiated Services Field is
described in Section 3 of [RFC 2474]. Updated terminology can be
found in [RFC 3260]. Standardized per-hop behavior is, for example,
described in [RFC 2597] ("Assured Forwarding PHB Group") and in
[RFC 3246] ("An Expedited Forwarding PHB").
The above-mentioned parameters are intended to support basic
integrated and differentiated services functionality in the network.
Additional parameters can be defined and standardized if required to
support specific services in the future.
2. Terminology and Abbreviations
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 [RFC 2119].
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3. QoS Parameter Encoding
3.1. TMOD-1 AVP
The TMOD-1 AVP is obtained from [RFC 2210] and [RFC 2215]. The
structure of the AVP is as follows:
TMOD-1 ::= < AVP Header: 495 >
{ Token-Rate }
{ Bucket-Depth }
{ Peak-Traffic-Rate }
{ Minimum-Policed-Unit }
{ Maximum-Packet-Size }
3.1.1. Token-Rate AVP
The Token-Rate AVP (AVP Code 496) is of type Float32.
3.1.2. Bucket-Depth AVP
The Bucket-Depth AVP (AVP Code 497) is of type Float32.
3.1.3. Peak-Traffic-Rate AVP
The Peak-Traffic-Rate AVP (AVP Code 498) is of type Float32.
3.1.4. Minimum-Policed-Unit AVP
The Minimum-Policed-Unit AVP (AVP Code 499) is of type Unsigned32.
3.1.5. Maximum-Packet-Size AVP
The Maximum-Packet-Size AVP (AVP Code 500) is of type Unsigned32.
3.2. TMOD-2 AVP
A description of the semantics of the parameter values can be found
in [RFC 2215]. The coding for the TMOD-2 AVP is as follows:
TMOD-2 ::= < AVP Header: 501 >
{ Token-Rate }
{ Bucket-Depth }
{ Peak-Traffic-Rate }
{ Minimum-Policed-Unit }
{ Maximum-Packet-Size }
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3.3. Bandwidth AVP
The Bandwidth AVP (AVP Code 502) is of type Float32 and is measured
in octets of IP datagrams per second. The Bandwidth AVP represents a
simplified description of the following TMOD setting whereby the
token rate (r) = peak traffic rate (p), the bucket depth (b) = large,
and the minimum policed unit (m) = large when only bandwidth has to
be expressed.
3.4. PHB-Class AVP
The PHB-Class AVP (AVP Code 503) is of type Unsigned32.
A description of the semantics of the parameter values can be found
in [RFC 3140]. The registries needed for usage with [RFC 3140] already
exist and hence a new registry is not required for this purpose. The
encoding requires that three cases be differentiated. All bits
indicated as "reserved" MUST be set to zero (0).
3.4.1. Case 1: Single PHB
As prescribed in [RFC 3140], the encoding for a single PHB is the
recommended Differentiated Services Code Point (DSCP) value for that
PHB, left-justified in the 16-bit field with bits 6 through 15 set to
zero.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DSCP |0 0 0 0 0 0 0 0 0 0| (Reserved) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
3.4.2. Case 2: Set of PHBs
The encoding for a set of PHBs is the numerically smallest of the set
of encodings for the various PHBs in the set, with bit 14 set to 1.
(Thus, for the AF1x PHBs, the encoding is that of the AF11 PHB, with
bit 14 set to 1.)
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DSCP |0 0 0 0 0 0 0 0 1 0| (Reserved) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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3.4.3. Case 3: Experimental or Local Use PHBs
PHBs may not be defined by standards actions i.e., experimental or
local use PHBs as allowed by [RFC 2474]. In this case, an arbitrary
12-bit PHB identification code, assigned by the IANA, is left-
justified in the 16-bit field. Bit 15 is set to 1, and bit 14 is
zero for a single PHB or 1 for a set of PHBs. Bits 12 and 13 are
zero.
Bits 12 and 13 are reserved either for expansion of the PHB
identification code or for other, future use.
In both cases, when a single PHBID is used to identify a set of PHBs
(i.e., bit 14 is set to 1), that set of PHBs MUST constitute a PHB
Scheduling Class (i.e., use of PHBs from the set MUST NOT cause
intra-microflow traffic reordering when different PHBs from the set
are applied to traffic in the same microflow). The set of AF1x PHBs
[RFC 2597] is an example of a PHB Scheduling Class. Sets of PHBs that
do not constitute a PHB Scheduling Class can be identified by using
more than one PHBID.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PHD ID CODE |0 0 1 0| (Reserved) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
4. Extensibility
This document is designed with extensibility in mind, given that
different organizations and groups are used to defining their own
Quality of Service parameters. This document provides an initial QoS
profile with a common set of parameters. Ideally, these parameters
should be used whenever possible, but there are cases where
additional parameters might be needed or where the parameters
specified in this document are used with different semantics. In
that case, it is advisable to define a new QoS profile that may
consist of new parameters in addition to parameters defined in this
document or an entirely different set of parameters. Finally, it is
also possible to register a specific QoS profile that defines a
specific set of QoS values rather than parameters that need to be
filled with values in order to be used.
To enable the definition of new QoS profiles, an 8-octet registry is
defined as a field that is represented by 4-octet vendor and 4-octet
specifier fields. The vendor field contains an Enterprise Number as
defined in [RFC 2578], taken from the values maintained in the IANA
Enterprise Numbers registry. If the four octets of the vendor field
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RFC 5624 QoS Parameters August 2009
are 0x00000000 (reserved value for IANA), then the value in the
specifier field MUST be registered with IANA (see Section 5.2). If
the vendor field is other than 0x00000000, the value of the specifier
field represents a vendor-specific value, where allocation is the
responsibility of the enterprise indicated in the vendor field.
5. IANA Considerations
5.1. AVP Codes
IANA allocated AVP codes in the IANA-controlled namespace registry
specified in Section 11.1.1 of [RFC 3588] for the following AVPs that
are defined in this document.
+------------------------------------------------------------------+
| AVP Section |
|AVP Name Code Defined Data Type |
+------------------------------------------------------------------+
|TMOD-1 495 3.1 Grouped |
|Token-Rate 496 3.1.1 Float32 |
|Bucket-Depth 497 3.1.2 Float32 |
|Peak-Traffic-Rate 498 3.1.3 Float32 |
|Minimum-Policed-Unit 499 3.1.4 Unsigned32 |
|Maximum-Packet-Size 500 3.1.5 Unsigned32 |
|TMOD-2 501 3.2 Grouped |
|Bandwidth 502 3.3 Float32 |
|PHB-Class 503 3.4 Unsigned32 |
+------------------------------------------------------------------+
5.2. QoS Profile
The QoS profile refers to a 64-bit field that is represented by
4-octet vendor and 4-octet specifier fields. The vendor field
indicates the type as either standards-specified or vendor-specific.
If the four octets of the vendor field are 0x00000000, then the value
is standards-specified and a registry will be created to maintain the
QoS profile specifier values. The specifier field indicates the
actual QoS profile. Depending on the value requested, the action
needed to request a new value is:
0 to 511: Standards Action
512 to 32767: Specification Required
32768 to 4294967295: Reserved
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Standards action is required to add, depreciate, delete, or modify
QoS profile values in the range of 0-511, and a specification is
required to add, depreciate, delete, or modify existing QoS profile
values in the range of 512-32767.
IANA created such a registry and allocated the value zero (0) for the
QoS profile defined in this document.
Alternative vendor-specific QoS profiles can be created and
identified with an Enterprise Number taken from the IANA registry
created by [RFC 2578] in the vendor field, combined with a vendor-
specific value in the specifier field. Allocation of the specifier
values is the responsibility of the vendor.
6. Security Considerations
This document does not raise any security concerns as it only defines
QoS parameters and does not yet describe how they are exchanged in an
Authentication, Authorization, and Accounting (AAA) protocol.
Security considerations are described in documents using this
specification.
7. Acknowledgements
The authors would like to thank the NSIS working group members
Cornelia Kappler, Jerry Ash, Attila Bader, and Dave Oran; the former
NSIS working group chairs John Loughney and Martin Stiemerling; and
the former Transport Area Directors Allison Mankin and Jon Peterson
for their help.
We would like to thank Ken Carlberg, Lars Eggert, Jan Engelhardt,
Francois Le Faucheur, John Loughney, An Nguyen, Dave Oran, James
Polk, Martin Dolly, Martin Stiemerling, and Magnus Westerlund for
their feedback regarding some of the parameters in this documents.
Jerry Ash, Al Morton, Mayutan Arumaithurai, and Xiaoming Fu provided
help with the semantics of some QSPEC parameters.
We would like to thank Dan Romascanu for his detailed Area Director
review comments and Scott Bradner for his Transport Area Directorate
review. Chris Newman, Adrian Farrel, and Pasi Eronen provided
feedback during the IESG review.
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8. References
8.1. Normative References
[RFC 2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC 2210] Wroclawski, J., "The Use of RSVP with IETF Integrated
Services", RFC 2210, September 1997.
[RFC 2215] Shenker, S. and J. Wroclawski, "General Characterization
Parameters for Integrated Service Network Elements",
RFC 2215, September 1997.
[RFC 2474] Nichols, K., Blake, S., Baker, F., and D. Black,
"Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers", RFC 2474,
December 1998.
[RFC 2578] McCloghrie, K., Ed., Perkins, D., Ed., and J.
Schoenwaelder, Ed., "Structure of Management Information
Version 2 (SMIv2)", STD 58, RFC 2578, April 1999.
[RFC 3140] Black, D., Brim, S., Carpenter, B., and F. Le Faucheur,
"Per Hop Behavior Identification Codes", RFC 3140,
June 2001.
[RFC 3588] Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J.
Arkko, "Diameter Base Protocol", RFC 3588, September 2003.
8.2. Informative References
[RFC 2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
and W. Weiss, "An Architecture for Differentiated
Services", RFC 2475, December 1998.
[RFC 2597] Heinanen, J., Baker, F., Weiss, W., and J. Wroclawski,
"Assured Forwarding PHB Group", RFC 2597, June 1999.
[RFC 2697] Heinanen, J. and R. Guerin, "A Single Rate Three Color
Marker", RFC 2697, September 1999.
[RFC 3246] Davie, B., Charny, A., Bennet, J., Benson, K., Le Boudec,
J., Courtney, W., Davari, S., Firoiu, V., and D.
Stiliadis, "An Expedited Forwarding PHB (Per-Hop
Behavior)", RFC 3246, March 2002.
Korhonen, et al. Standards Track [Page 9]
RFC 5624 QoS Parameters August 2009
[RFC 3260] Grossman, D., "New Terminology and Clarifications for
Diffserv", RFC 3260, April 2002.
Korhonen, et al. Standards Track [Page 10]
RFC 5624 QoS Parameters August 2009
Appendix A. ABNF Code Fragment
Copyright (c) 2009 IETF Trust and the persons identified as authors
of the code. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
o Redistributions of source code must retain the above copyright
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o Redistributions in binary form must reproduce the above copyright
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o Neither the name of Internet Society, IETF or IETF Trust, nor the
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
'AS IS' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
TMOD-1 ::= < AVP Header: 495 >
{ Token-Rate }
{ Bucket-Depth }
{ Peak-Traffic-Rate }
{ Minimum-Policed-Unit }
{ Maximum-Packet-Size }
TMOD-2 ::= < AVP Header: 501 >
{ Token-Rate }
{ Bucket-Depth }
{ Peak-Traffic-Rate }
{ Minimum-Policed-Unit }
{ Maximum-Packet-Size }
Korhonen, et al. Standards Track [Page 11]
RFC 5624 QoS Parameters August 2009
Authors' Addresses
Jouni Korhonen (editor)
Nokia Siemens Networks
Linnoitustie 6
Espoo 02600
Finland
EMail: jouni.korhonen@nsn.com
Hannes Tschofenig
Nokia Siemens Networks
Linnoitustie 6
Espoo 02600
Finland
Phone: +358 (50) 4871445
EMail: Hannes.Tschofenig@gmx.net
URI: http://www.tschofenig.priv.at
Elwyn Davies
Folly Consulting
Soham
UK
Phone: +44 7889 488 335
EMail: elwynd@dial.pipex.com
Korhonen, et al. Standards Track [Page 12]