Diameter Maintenance and K. Carlberg, Ed. Extensions (DIME) G11 Internet-Draft T. Taylor Intended status: Standards Track Huawei Technologies July 5, 2011 Diameter Priority Attribute Value Pairs draft-ietf-dime-priority-avps-04.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. 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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. Carlberg & Taylor Expires January 5, 2012 [Page 1] Internet Drafts Resource Priority AVPs July 5, 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 January 5, 2012 [Page 2] Internet Drafts Resource Priority AVPs July 5, 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. 3.1.2. Defending-Priority AVP Carlberg & Taylor Expires January 5, 2012 [Page 3] Internet Drafts Resource Priority AVPs July 5, 2012 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 > { ALRP-Namespace } { ALRP-Value } Carlberg & Taylor Expires January 5, 2012 [Page 4] Internet Drafts Resource Priority AVPs July 5, 2012 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 January 5, 2012 [Page 5] Internet Drafts Resource Priority AVPs July 5, 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 the extension of Diameter for conveying Quality of Service information. The security considerations of the Diameter protocol itself have been 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 listed below. 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. [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 Carlberg & Taylor Expires January 5, 2012 [Page 6] Internet Drafts Resource Priority AVPs July 5, 2012 [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 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 January 5, 2012 [Page 7]