Diameter Maintenance and K. Carlberg, Ed. Extensions (DIME) G11 Internet-Draft H. Tschofenig Intended status: Standards Track Nokia Siemens Networks Oct 19, 2009 Diameter Priority Attribute Value Pairs 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), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. 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. Abstract This document defines various priority parameters for use with Diameter and the AAA framework. These parameters are defined in several different protocols that operate at either the network or application layer. Carlberg & Tschofenig Expires April 19, 2010 [Page 1] Internet Drafts Resource Priority Attribute Oct 19, 2009 1. Introduction This document defines a number of priority parameters that can be reused for conveying priority labeled information within the Diameter protocol [RFC3588]. It defines an initial priority profile containing a set of Diameter encoded Attribute Value Pairs (AVPs) described using a modified version of the Augmented Backus-Naur Form (ABNF), see [RFC3588]. The data types are also taken from [RFC3588]. Priority influences the distribution of resources. This influence may be probabilistic ranging between (but not including) 0% and 100%, or it may be binary (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 as 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. One can also argue that the lack of contention (or congested state) of the shared resource implies that packets of flow(s) are forwarded at the same rate (minus a constant processing overhead) they are received with no appreciable difference in QoS experienced by any packet. A third example of how prioritization can be realized is articulated in Appendix A.3 (the priority by-pass model) of [draft.rsvp- priority-extension]. In this case, prioritized flows may grant access to resources that are never shared with non-prioritized flows. 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 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, which are derived from the corresponding priority fields in the Signaled Policy Element Carlberg & Tschofenig Expires April 19, 2010 [Page 2] Internet Drafts Resource Priority Attribute Oct 19, 2009 [rfc3181] of RSVP [rfc2205]. The Defending-Priority is set when the reservation has been admitted. The Preemption-Priority of a newly requested reservation and is compared with the Defending Priority of a previously admitted flow. Actions taken upon this comparison is 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 Unsigned32. Higher values represent higher priority. 3.1.2. Defending-Priority AVP The Defending-Priority AVP (AVP Code TBD) is of type Unsigned32. Higher values represent higher priority. 3.2. Admission-Priority AVP The Admission-Priority AVP (AVP Code TBD) is of type Unsigned32. The admission control priority of the flow used to increase the probability of session establishment to 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 3.1 of [I-D.ietf-tsvwg-emergency-rsvp]. 3.3. ALRP AVP The Application-Level Resource Priority (ALRP) AVP is a grouped AVP consisting of two AVPs, the ALRP-Namespace and the ALRP-Priority AVP. A description of the semantic of the parameter values can be found in [RFC4412] and in [I-D.ietf-tsvwg-emergency-rsvp]. The coding for parameter is as follows: ALRP ::= < AVP Header: TBD > { ALRP-Namespace } { ALRP-Priority } 3.3.1. ALRP-Namespace AVP The ALRP-Namespace AVP (AVP Code TBD) is of type Unsigned32. Carlberg & Tschofenig Expires April 19, 2010 [Page 3] Internet Drafts Resource Priority Attribute Oct 19, 2009 3.3.2. ALRP-Priority AVP The ALRP-Priority AVP (AVP Code TBD) is of type Unsigned32. [RFC4412] defines a resource priority header and established the initial registry. That registry was later extended by [I-D.ietf- tsvwg-emergency-rsvp]. 3.4. SIP-RPH AVP The SIP-RPH AVP is a grouped AVP consisting of two AVPs, the SIP- Namespace and the SIP-Value AVP, which are derived from the corresponding optional header fields in [rfc4412]. The SIP-Namespace identifies a particular set of priorities. The SIP-Value identifies a specific priority associated with the SIP-Namespace. SIP-RPH ::= { SIP-Namespace } { SIP-Value } 3.4.1. SIP-Namespace AVP The SIP-Namespace AVP (AVP Code TBD) is of type UTF8String. 3.4.2 SIP-Value AVP The SIP-Value AVP (AVP Code TBD) is of type UTF8String. 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 | |ALRP TBD 3.3 Grouped | |ALRP-Namespace TBD 3.3.1 Unsigned32 | |ALRP-Priority TBD 3.3.2 Unsigned32 | |SIP-RPH TBD 3.4 Grouped | |SIP-Namespace TBD 3.4.1 UTF8String | |SIP-Value TBD 3.4.2 UTF8String | +------------------------------------------------------------------+ Carlberg & Tschofenig Expires April 19, 2010 [Page 4] Internet Drafts Resource Priority Attribute Oct 19, 2009 4.2. QoS Profile IANA is requested to allocate a new value from the registry defined in [I-D.ietf-dime-qos-parameters] for the QoS profile defined in this document. 5. Examples +--------+ +--------+ |Diameter| | SIP | | server | | server | +--------+ +--------+ | | | | | | 1. SIP INVITE w/ RPH | ------------------------------>| | 2. MAR w/ SIP-RPH AVP | |<----------------------| | 3. MAA. | |---------------------->| 8. SIP INVITE | |----------------> | | 9. SIP 200 (OK) 10. SIP 200 (OK) |<---------------- <------------------------------| | | 6. Security Considerations TBD 7. Acknowledgements We would like to thank 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. Additionally, we would like to thank Martin Dolly and Viqar Shaikh for their feedback. 8. References 8.1. Normative References [I-D.ietf-dime-qos-parameters] Korhonen, J., Tschofenig, H., and E. Davies, "Quality of Service Parameters for Usage with Diameter", Carlberg & Tschofenig Expires April 19, 2010 [Page 5] Internet Drafts Resource Priority Attribute Oct 19, 2009 draft-ietf-dime-qos-parameters-11 (work in progress) May 2009. [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-12 (work in progress), May 2009. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3181] Herzog, S., "Signaled Preemption Priority Policy Element", RFC 3181, October 2001. [RFC3588] Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J. Arkko, "Diameter Base Protocol", RFC 3588, September 2003. [RFC4124] Le Faucheur, F., "Protocol Extensions for Support of Diffserv-aware MPLS Traffic Engineering", RFC 4124, June 2005. [RFC4412] Schulzrinne, H. and J. Polk, "Communications Resource Priority for the Session Initiation Protocol (SIP)", RFC 4412, February 2006. 8.2. Informative References [I-D.ietf-nsis-qspec] Bader, A., Kappler, C., and D. Oran, "QoS NSLP QSPEC Template", draft-ietf-nsis-qspec-21 (work in progress), November 2008. [RFC3564] Le Faucheur, F. and W. Lai, "Requirements for Support of Differentiated Services-aware MPLS Traffic Engineering", RFC 3564, July 2003. Authors' Addresses Ken Carlberg (editor) Hannes Tschofenig G11 Nokia Siemens Networks 1601 Clarendon Dr Linnoitustie 6 Espoo 02600 Arlington, VA 22209 Finland United States Phone: +358 (50) 4871445 Email: carlberg@g11.org.uk Email: Hannes.Tschofenig@gmx.net URI:http://www.tschofenig.priv.at Carlberg & Tschofenig Expires April 19, 2010 [Page 6]