Diameter Maintenance and K. Carlberg, Ed.
Extensions (DIME) G11
Internet-Draft T. Taylor
Intended status: Standards Track Huawei Technologies
Oct 31, 2011
Diameter Priority Attribute Value Pairs
draft-ietf-dime-priority-avps-05.txt
Status of this Memo
This Internet-Draft is submitted to IETF 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
http://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."
Copyright Notice
Copyright (c) 2011 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 (http://trustee.ietf.org/license-info) in
effect on the date of publication of this document. Please review these
documents carefully, as they describe your rights and restrictions with
respect to this document. Code Components extracted from this document
must include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
This document may contain material from IETF Documents or IETF
Contributions published or made publicly available before November 10,
2008. The person(s) controlling the copyright in some of this material
may not have granted the IETF Trust the right to allow modifications of
such material outside the IETF Standards Process. Without obtaining an
adequate license from the person(s) controlling the copyright in such
materials, this document may not be modified outside the IETF Standards
Process, and derivative works of it may not be created outside the IETF
Standards Process, except to format it for publication as an RFC or to
translate it into languages other than English.
Carlberg & Taylor Expires April 26, 2012 [Page 1]
Internet Drafts Resource Priority AVPs Oct 31, 2012
Abstract
This document defines Attribute-Value Pair (AVP) containers for various
priority parameters for use with Diameter and the AAA framework. The
parameters themselves are defined in several different protocols that
operate at either the network or application layer.
1. Introduction
This document defines a number of Attribute-Value Pairs (AVP) that can
be used within the Diameter protocol [I-D.ietf-dime-rfc3588bis] to
convey a specific set of priority parameters. These parameters are
specified in other documents, but are briefly described below. The
corresponding AVPs defined in Section 3 are an extension to those
defined in [RFC5866]. We note that all the priority fields associated
with the AVPs defined in this document are extensible and allow for
additional values beyond what may have already been defined or
registered with IANA.
Priority influences the distribution of resources. This influence may
be probabilistic, ranging between (but not including) 0% and 100%, or it
may be in the form of a guarantee to either receive or not receive the
resource.
The influence attributed to prioritization may also affect QoS, but it
is not to be confused with QoS. As an example, if packets of two or more
flows are contending for the same shared resources, prioritization helps
determine which packet receives the resource. However, this allocation
of resource does not correlate directly to any specific delay or loss
bounds that have been associated with the packet.
Another example of how prioritization can be realized is articulated in
Appendix A.3 (the priority by-pass model) of
[I-D.ietf-tsvwg-emergency-rsvp]. In this case, prioritized flows may
gain access to resources that are never shared with non-prioritized
flows.
1.1 Other Priority-Related AVPs
3rd Generation Partnership Project (3GPP) has defined several Diameter
AVPs that support prioritization of sessions. The following AVPs are
intended to be used for priority services (e.g., Multimedia Priority
Service):
- Reservation-Priority AVP as defined in [ETSI]
- MPS-Identifier AVP as defined in [3GPPa]
- Priority-Level AVP (as part of the Allocation Retention Priority
AVP) as defined in [3GPPb]
Carlberg & Taylor Expires April 26, 2012 [Page 2]
Internet Drafts Resource Priority AVPs Oct 31, 2012
- Session-Priority AVP as defined in [3GPPc][3GPPd]
Both the Reservation-Priority AVP and the Priority-Level AVP can carry
priority levels associated with a session initiated by a user. We note
that these AVPs are defined from the allotment set aside for 3GPP for
Diameter-based interfaces. 3GPP has also defined other priority
information for use on non-Diameter based interfaces. However, this
work is not relevant to the present document. The AVPs defined by 3GPP
are to be viewed as private implementations operating within a walled
garden.
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 RFC2119 [RFC2119].
3. Priority Parameter Encoding
This section defines a set of priority AVPs. This set is for use with
the DIAMETER QoS application [RFC5866] and represents a continuation of
the list of AVPs defined in [RFC5624]. The syntax notation used is that
of [I-D.ietf-dime-rfc3588bis].
3.1. Dual-Priority AVP
The Dual-Priority AVP is a grouped AVP consisting of two AVPs; the
Preemption-Priority and the Defending-Priority AVP. These AVPs are
derived from the corresponding priority fields specified in the Signaled
Preemption Priority Policy Element [RFC3181] of RSVP [RFC2205]. The
Defending-Priority is set when the reservation has been admitted. The
Preemption-Priority of a newly requested reservation is compared with
the Defending Priority of a previously admitted flow. The actions taken
based upon the result of this comparison are a function of local policy.
Dual-Priority ::= < AVP Header: TBD >
{ Preemption-Priority }
{ Defending-Priority }
3.1.1. Preemption-Priority AVP
The Preemption-Priority AVP (AVP Code TBD) is of type Unsigned16.
Higher values represent higher priority. The value encoded in this AVP
is the same as the preemption priority value that would be encoded in
the signaled preemption priority policy element.
Carlberg & Taylor Expires April 26, 2012 [Page 3]
Internet Drafts Resource Priority AVPs Oct 31, 2012
3.1.2. Defending-Priority AVP
The Defending-Priority AVP (AVP Code TBD) is of type Unsigned16. Higher
values represent higher priority. The value encoded in this AVP is the
same as the defending priority value that would be encoded in the
signaled preemption priority policy element.
3.2. Admission-Priority AVP
The Admission-Priority AVP (AVP Code TBD) is of type Unsigned8. The
admission priority of the flow is used to increase the probability of
session establishment for selected flows. Higher values represent
higher priority. A given admission priority is encoded in this
information element using the same value as when encoded in the
admission priority parameter defined in Section 5.1 of
[I-D.ietf-tsvwg-emergency-rsvp].
3.3. SIP-Resource-Priority AVP
The SIP-Resource-Priority AVP is a grouped AVP consisting of two AVPs,
the SIP-Resource-Priority-Namespace and the SIP-Resource- Priority-Value
AVP, which are derived from the corresponding optional header fields in
[rfc4412].
SIP-Resource-Priority ::= < AVP Header: TBD >
{ SIP-Resource-Priority-Namespace }
{ SIP-Resource-Priority-Value }
3.3.1. SIP-Namespace AVP
The SIP-Resource-Priority-Namespace AVP (AVP Code TBD) is of type
UTF8String. This AVP contains a string that identifies a unique ordered
set of priority values as described in [rfc4412].
3.3.2 SIP-Resource-Priority-Value AVP
The SIP-Resource-Priority-Namespace AVP (AVP Code TBD) is of type
UTF8String. This AVP contains a string (i.e., a Namespace entry) that
identifies a set of priority values unique to the Namespace. Examples
of Namespaces and corresponding sets of priorities are found in
[rfc4412].
3.4. Application-Level-Resource-Priority AVP
The Application-Level-Resource-Priority (ALRP) AVP is a grouped AVP
consisting of two AVPs, the ALRP-Namespace AVP and the ALRP-Value AVP.
Application-Level-Resource-Priority ::= < AVP Header: TBD >
Carlberg & Taylor Expires April 26, 2012 [Page 4]
Internet Drafts Resource Priority AVPs Oct 31, 2012
{ ALRP-Namespace }
{ ALRP-Value }
A description of the semantics of the parameter values can be found in
[RFC4412] and in [I-D.ietf-tsvwg-emergency-rsvp]. The registry set up
by [RFC4412] provided string values for both the priority namespace and
the priority values associated with that namespace.
[I-D.ietf-tsvwg-emergency-rsvp] modifies that registry to assign
numerical values to both the namespace identifiers and the priority
values within them. Consequently, SIP-Resource-Priority and
Application-Level-Resource-Priority AVPs convey the same priority
semantics, but with differing syntax. In the former case, an
alpha-numeric encoding is used, while the latter case is constrained to
a numeric-only value.
3.4.1. ALRP-Namespace AVP
The ALRP-Namespace AVP (AVP Code TBD) is of type Unsigned16. This AVP
contains a numerical value identifying the namespace of the
application-level resource priority as described in
[I-D.ietf-tsvwg-emergency-rsvp].
3.4.2. ALRP-Value AVP
The ALRP-Priority AVP (AVP Code TBD) is of type Unsigned8. This AVP
contains the priority value within the ALRP-Namespace, as described in
[I-D.ietf-tsvwg-emergency-rsvp].
4. IANA Considerations
4.1. AVP Codes
IANA is requested to allocate AVP codes for the following AVPs that are
defined in this document.
+------------------------------------------------------------------+
| AVP Section |
|AVP Name Code Defined Data Type |
+------------------------------------------------------------------+
|Dual-Priority TBD 3.1 Grouped |
|Preemption-Priority TBD 3.1.1 Unsigned32 |
|Defending-Priority TBD 3.1.2 Unsigned32 |
|Admission-Priority TBD 3.2 Unsigned32 |
|SIP-Resource-Priority TBD 3.3 Grouped |
|SIP-Namespace TBD 3.3.1 UTF8String |
|SIP-Value TBD 3.3.2 UTF8String |
|Application-Level-Resource-Priority TBD 3.4 Grouped |
|ALRP-Namespace TBD 3.4.1 Unsigned32 |
|ALRP-Value TBD 3.4.2 Unsigned32 |
+------------------------------------------------------------------+
Carlberg & Taylor Expires April 26, 2012 [Page 5]
Internet Drafts Resource Priority AVPs Oct 31, 2012
4.2. QoS Profile
IANA is requested to allocate a new value from the Authentication,
Authorization, and Accounting (AAA) Parameters/QoS Profile registry
defined in [RFC5624] for the QoS profile defined in this document. The
name of the profile is "Resource priority parameters".
5. Security Considerations
This document describes an extension for conveying Quality of Service
information, and therefore follows the same security considerations of
the Diameter QoS Application [RFC5866]. The values placed in the AVPs
are not changed by this draft, nor are they changed in the Diameter QoS
application. The consequences of changing values in the Priority
AVPs may result in an allocation of additional or less resources. If local
policy exists and values placed in the AVPs do not have integrity protection
(e.g., the use of S/MIME with the SIP RPH, or an INTEGRITY object within
a POLICY_DATA object), then changes and their consequences may occur.
Otherwise, integrity protected values SHOULD be ignored with appropriate
protocol specific error messages sent back upstream. Note that we do not
use the term "MUST be ignored" because local policy of an administrative
domain associated with other protocols acts as the final arbiter.
The security considerations of the Diameter protocol itself are discussed
in [I-D.ietf-dime-rfc3588bis]. Use of the AVPs defined in this document
MUST take into consideration the security issues and requirements of the
Diameter base protocol.
The authors also recommend that readers should familiarize themselves
with the security considerations of the various protocols listed in the
Normative References. This is because values placed in the AVPs defined
in this draft are set/changed by other protocols.
6. Acknowledgements
We would like to thank Lionel Morand, Janet Gunn, Piers O'Hanlon for the
commenst on the draft, and Lars Eggert, Jan Engelhardt, Francois
LeFaucheur, John Loughney, An Nguyen, Dave Oran, James Polk, Martin
Stiemerling, and Magnus Westerlund for their help with resolving
problems regarding the Admission Priority and the ALRP parameter.
7. References
7.1. Normative References
[I-D.ietf-dime-rfc3588bis]
Fajardo, V., Arkko, J., Loughney, J., and G. Zorn,
"Diameter Base Protocol", draft-ietf-dime-rfc3588bis-26
(work in progress), January 2011.
Carlberg & Taylor Expires April 26, 2012 [Page 6]
Internet Drafts Resource Priority AVPs Oct 31, 2012
[I-D.ietf-tsvwg-emergency-rsvp]
Faucheur, F., Polk, J., and K. Carlberg, "Resource
ReSerVation Protocol (RSVP) Extensions for Emergency
Services", draft-ietf-tsvwg-emergency-rsvp-14 (work in
progress), Nov 2009.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2205] Braden, B., et. al., "Resource ReSerVation Protocol (RSVP)
-- Version 1 Functional Specification", RFC 2205, September
1997
[RFC3181] Herzog, S., "Signaled Preemption Priority Policy Element",
RFC 3181, October 2001.
[RFC4412] Schulzrinne, H. and J. Polk, "Communications Resource
Priority for the Session Initiation Protocol (SIP)",
RFC 4412, February 2006.
[RFC5624] Korhonen, J., Tschofenig, H., and E. Davies, "Quality of
Service Parameters for Usage with Diameter", RFC 5624,
Aug 2009.
[RFC5866] Sun, D., et. al., "Diameter Quality-of-Service
Application", RFC 5866, May 2010.
7.2. Informative References
[3GPPa] "TS 29.214: Policy and charging control over Rx reference
point", 3GPP, March, 2011
[3GPPb] "TS 29.212: Policy and charging control over Gx reference
point", 3GPP, October, 2010
[3GPPc] "TS 29.229: Cx and Dx interfaces based on the Diameter
protocol; Protocol details", 3GPP, September, 2010
[3GPPd] "TS 29.329: Sh interface based on the Diameter protocol;
Protocol details", 3GPP, September, 2010
[ETSI] "TS 183 017: Telecommunications and Internet Converged
Services and Protocols for Advanced Networking (TISPAN);
Resource and Admission Control", ETSI
Authors' Addresses
Carlberg & Taylor Expires April 26, 2012 [Page 7]
Internet Drafts Resource Priority AVPs Oct 31, 2012
Ken Carlberg (editor) Tom Taylor
G11 Huawei Technologies
1601 Clarendon Dr 1852 Lorraine Ave
Arlington, VA 22209 Ottawa
United States Canada
Email: carlberg@g11.org.uk Email: tom111.taylor@bell.net
Carlberg & Taylor Expires April 26, 2012 [Page 8]
