Diameter Maintenance and J. Korhonen, Ed. Extensions (DIME) H. Tschofenig Internet-Draft Nokia Siemens Networks Intended status: Standards Track E. Davies Expires:July 26,September 10, 2009 Folly ConsultingJanuary 22,March 9, 2009 Quality of Service Parameters for Usage with Diameterdraft-ietf-dime-qos-parameters-09.txtdraft-ietf-dime-qos-parameters-10.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), 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. This Internet-Draft will expire onJuly 26,September 10, 2009. 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(http://trustee.ietf.org/license-info)in effect on the date of publication of thisdocument.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 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,bandwidth, defendinga bandwidth parameter, andpreemption priority, admission priority, application-level resource priority, per-hopa per- hop behaviorclass, and DiffServ-aware Multiprotocol Label Switching (MPLS) traffic engineering.class object. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology and Abbreviations . . . . . . . . . . . . . . . . 4 3. QoS Parameter Encoding . . . . . . . . . . . . . . . . . . . . 4 3.1. TMOD-1 AVP . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1.1.TMOD-RateToken-Rate AVP . . . . . . . . . . . . . . . . . . . . 4 3.1.2.TMOD-SizeBucket-Depth AVP . . . . . . . . . . . . . . . . . . ..4 3.1.3.Peak-Data-RatePeak-Traffic-Rate AVP . . . . . . . . . . . . . . . .. .4 3.1.4. Minimum-Policed-Unit AVP . . . . . . . . . . . . . . . 43.2. TMOD-2 AVP . . . . . . . . . . . . . . . . . . . . . . . . 5 3.3. Bandwidth3.1.5. Maximum-Packet-Size AVP . . . . . . . . . . . . . . .. . . . . . .53.4. Priority3.2. TMOD-2 AVP . . . . . . . . . . . . . . . . . . . . . . .5 3.4.1. Preemption-Priority AVP . . . . . . . . . . . . . .. 53.4.2. Defending-Priority3.3. Bandwidth AVP . . . . . . . . . . . . . . . .5 3.5. Admission-Priority AVP . . . . . . . . . . . .. . . . . . 53.6. ALRP AVP . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.6.1. ALRP-Namespace AVP . . . . . . . . . . . . . . . . . . 6 3.6.2. ALRP-Priority AVP . . . . . . . . . . . . . . . . . . 6 3.7.3.4. PHB-Class AVP . . . . . . . . . . . . . . . . . . . . . .6 3.7.1.5 3.4.1. Case 1: Single PHB . . . . . . . . . . . . . . . . . .6 3.7.2.5 3.4.2. Case 2: Set of PHBs . . . . . . . . . . . . . . . . .7 3.7.3.6 3.4.3. Case 3: Experimental or Local Use PHBs . . . . . . . .7 3.8. DSTE-Class-Type AVP . . . . . . . . . . . . . . . . . . . 86 4. Extensibility . . . . . . . . . . . . . . . . . . . . . . . .86 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . .87 6. Security Considerations . . . . . . . . . . . . . . . . . . .108 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . .108 8. References . . . . . . . . . . . . . . . . . . . . . . . . . .109 8.1. Normative References . . . . . . . . . . . . . . . . . . .109 8.2. Informative References . . . . . . . . . . . . . . . . . .119 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . .1210 1. Introduction This document defines a number of Quality of Service (QoS) parameters that can be reused for conveying QoS information within the Diameterprotocol. This documentprotocol [RFC3588]. It defines an initial QoS profile containing a set ofQoS AVPs.Diameter encoded Attribute Value Pairs (AVPs) described using a modified version of the Augmented Backus-Naur Form (ABNF), see [RFC3588]. The datatypes are also taken from [RFC3588]. The traffic model (TMOD) AVPs are containers consisting of four AVPs and is a way to describe the traffic source. o token rate (r) o bucketsizedepth (b) o peak traffic rate (p) o minimum policed unit (m) o maximum packet size (M) The encoding of the <TMOD-1> and the <TMOD-2> AVP can be found in Section 3.1 and Section3.2 and the semantic is3.2. The semantics of these two AVPs are described in Section 3.1 of [RFC2210] and in Section 3.6 of [RFC2215]. The <TMOD-2> AVP is, for example, needed by some DiffServ applications. It is typically assumed that DiffServ 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 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. [RFC2697] 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. [RFC2697] 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 [RFC2597].The <Preemption-Priority> AVP refers to the priority of a new flow compared with the <Defending-Priority> AVP of previously admitted flows. Once a flow is admitted, the preemption priority becomes irrelevant. The <Defending-Priority> AVP is used to compare with the preemption priority of new flows. For any specific flow, its preemption priority is always less than or equal to the defending priority. The <Admission-Priority> AVP and <ALRP> AVP provide an essential way to differentiate flows for emergency services, ETS, E911, etc., and assign them a higher admission priority than normal priority flows and best-effort priority flows. Resource reservations might referResource reservations might refer to a packet processing with a particular DiffServ per-hop behavior (PHB)[RFC2475](using the<PHB- Class> AVP) or to a particular QoS class, e.g., a DiffServ-aware MPLS traffic engineering (DSTE) class type, as<PHB-Class> AVP). A generic description of the DiffServ architecture can be found in [RFC2475] and the Differentiated Services Field is described in[RFC3564]Section 3 of [RFC2474]. Updated terminology can be found in [RFC3260]. Standardized Per-Hop Behavior is, for example, described in [RFC2597] (Assured Forwarding Per-Hop Behavior) and in [RFC3246] (An Expedited Forwarding Per-Hop Behavior). The above-mentioned parameters are intended to support basic integrated and differentiated services functionality in[RFC4124], usingthe<DSTE-Class-Type> AVP.network. Additional parameters can be defined and standardized if required to support specific services in 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 RFC2119 [RFC2119]. 3. QoS Parameter Encoding 3.1. TMOD-1 AVP The TMOD-1 AVP is obtained from [RFC2210] and [RFC2215]. The structure of the AVP is as follows: TMOD-1 ::= < AVP Header: TBD > {TMOD-RateToken-Rate } {TMOD-SizeBucket-Depth } {Peak-Data-RatePeak-Traffic-Rate } { Minimum-Policed-Unit } { Maximum-Packet-Size } 3.1.1.TMOD-RateToken-Rate AVP TheTMOD-RateToken-Rate AVP (AVP Code TBD) is of typeFloat32 and contains the rate (r).Float32. 3.1.2.TMOD-SizeBucket-Depth AVP TheTMOD-SizeBucket-Depth AVP (AVP Code TBD) is of typeFloat32 and contains the bucket size (b).Float32. 3.1.3.Peak-Data-RatePeak-Traffic-Rate AVP ThePeak-Data-RatePeak-Traffic-Rate AVP (AVP Code TBD) is of typeFloat32 and contains the peak rate (p).Float32. 3.1.4. Minimum-Policed-Unit AVP The Minimum-Policed-Unit AVP (AVP Code TBD) is of typeUnsigned32 and contains the minimum policed unit (m). 3.2. TMOD-2 AVP A description of the semantic of the parameter values can be found in [RFC2215]. The TMOD-2 AVP is useful in a DiffServ environment. The coding for the TMOD-2 AVP is as follows: TMOD-2 ::= < AVP Header: TBD > { TMOD-Rate } { TMOD-Size } { Peak-Data-Rate } { Minimum-Policed-Unit } 3.3. Bandwidth AVP The Bandwidth AVP (AVP Code TBD) is of type Float32 and is measured in bytes of IP datagrams per second. 3.4. Priority AVP The Priority AVP is a grouped AVP consisting of two AVPs, the Preemption-Priority and the Defending-Priority AVP. A description of the semantic can be found in [RFC3181]. Priority ::= < AVP Header: TBD > { Preemption-Priority } { Defending-Priority } 3.4.1. Preemption-Priority AVP The Preemption-Priority AVP (AVP Code TBD) is of type Unsigned32 and it indicates the priority of the new flow compared with the defending priority of previously admitted flows. Higher values represent higher priority. 3.4.2. Defending-Priority AVP The Defending-Priority AVP (AVP Code TBD) is of typeUnsigned32.Once a flow is admitted, the preemption priority becomes irrelevant. Instead, its defending priority is used to compare with the preemption priority of new flows. 3.5. Admission-Priority3.1.5. Maximum-Packet-Size AVP TheAdmission-PriorityMaximum-Packet-Size AVP (AVP Code TBD) is of type Unsigned32.The admission control priority of the flow, in terms of access to network bandwidth in order to provide higher probability of call completion 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 AVP defined in Section 3.1 of [I-D.ietf-tsvwg-emergency-rsvp] (Admission Priority parameter). 3.6. ALRP AVP The Application-Level Resource Priority (ALRP) AVP is a grouped3.2. TMOD-2 AVPconsisting 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].[RFC2215]. The coding forparameterthe TMOD-2 AVP is as follows:ALRPTMOD-2 ::= < AVP Header: TBD > {ALRP-NamespaceToken-Rate } {ALRP-PriorityBucket-Depth }3.6.1. ALRP-Namespace AVP The ALRP-Namespace AVP (AVP Code TBD) is of type Unsigned32. 3.6.2. ALRP-Priority{ Peak-Traffic-Rate } { Minimum-Policed-Unit } { Maximum-Packet-Size } 3.3. Bandwidth AVP TheALRP-PriorityBandwidth AVP (AVP Code TBD) is of typeUnsigned32. [RFC4412] defines a resource priority headerFloat32 andestablished the initial registry. That registry was later extended by [I-D.ietf-tsvwg-emergency-rsvp]. 3.7.is measured in octets of IP datagrams per second. 3.4. PHB-Class AVP The PHB-Class AVP (AVP Code TBD) is of type Unsigned32. A description of the semantic of the parameter values can be found in [RFC3140]. The registries needed for usage with [RFC3140] already exist and hence no new registry needs to be created by this document. The encoding requires three cases need to be differentiated. All bits indicated as "reserved" MUST be set to zero (0).3.7.1.3.4.1. Case 1: Single PHB As prescribed in [RFC3140], the encoding for a single PHB is the recommended 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) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+3.7.2.3.4.2. 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) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+3.7.3.3.4.3. Case 3: Experimental or Local Use PHBs PHBs not defined by standards action, i.e., experimental or local use PHBs as allowed by [RFC2474]. In this case an arbitrary 12 bit PHB identification code, assigned by the IANA, is placed 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 use, at some point in the future. 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 [RFC2597] 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) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+3.8. DSTE-Class-Type AVP The DSTE-Class-Type AVP (AVP Code TBD) is of type Unsigned32. A description of the semantic of the parameter values can be found in [RFC4124]. Currently, the values of alues currently allowed are 1, 2, 3, 4, 5, 6, 7. The value of zero (0) is marked as reserved in [RFC4124]. Furthermore, the CLASSTYPE attribute in [RFC4124] is 32 bits in length with 29 bits reserved.4. Extensibility This document is designed with extensibility in mind given that different organizations and groups are used todefinedefining their own Quality of Service parameters. This document provides an initial QoS profile with 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 a different semantic. 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 a 8 octet registry is defined field that is represented by a 4-octet vendor and 4-octet specifier field. The vendor fieldindicates the typecontains an Enterprise Number aseither standards-specified or vendor-specific.defined in [RFC2578] taken from the values maintained in the IANA Enterprise Numbers registry. If the four octets of the vendor field are0x00000000,0x00000000 (reserved value for IANA), then the valueis standards-specified andin theregistry is maintained byspecifier field MUST be registered with IANAas Enterprise Numbers defined in [RFC2578], and any(see Section 5.2). If the vendor field is other than 0x00000000, the value of the specifier field represents a vendor-specificObject Identifier (OID). IANA created registryvalue, where allocation issplit into two value ranges; one range usesthe"Standards Action" andresponsibility of thesecond range uses "Specification Required" allocation policy. The latter range is meant to be used by organizations outsideenterprise indicated in theIETF.vendor field. 5. IANA Considerations 5.1. AVP Codes IANA is requested to allocate AVP codes in the IETF IANA controlled namespace registry specified in Section 11.1.1 of [RFC3588] for the following AVPs that are defined in this document. +------------------------------------------------------------------+ | AVP Section | |AVP Name Code Defined Data Type | +------------------------------------------------------------------+ |TMOD-1 TBD 3.1 Grouped ||TMOD-Rate|Token-Rate TBD 3.1.1 Float32 ||TMOD-Size|Bucket-Depth TBD 3.1.2 Float32 ||Peak-Data-Rate|Peak-Traffic-Rate TBD 3.1.3 Float32 | |Minimum-Policed-Unit TBD 3.1.4 Unsigned32 | |Maximum-Packet-Size TBD 3.1.5 Unsigned32 | |TMOD-2 TBD 3.2 Grouped | |Bandwidth TBD 3.3 Float32 ||Priority TBD 3.4 Grouped | |Preemption-Priority TBD 3.4.1 Unsigned32 | |Defending-Priority TBD 3.4.2 Unsigned32 | |Admission-Priority TBD 3.5 Unsigned32 | |ALRP TBD 3.6 Grouped | |ALRP-Namespace TBD 3.6.1 Unsigned32 | |ALRP-Priority TBD 3.6.2 Unsigned32 ||PHB-Class TBD 3.7 Unsigned32 ||DSTE-Class-Type TBD 3.8 Unsigned32 |+------------------------------------------------------------------+ 5.2. QoS ProfileIANA is requested to create the following registry.The QoS Profile refers to a 64 bit long field that is represented by a 4-octet vendor and 4-octet specifier field. The vendor field indicates the type as either standards-specified or vendor-specific. If the four octets of the vendor field are 0x00000000, thenthe value is standards-specified and the registry is maintained by IANA, and any other value represents a vendor-specific Object Identifier (OID). The specifier field indicates the actual QoS profile. The vendor field 0x00000000 is reserved to indicate that the values in the specifier field are maintained by IANA. This document requests IANA to create suchthe value is standards-specified and a registryandwill be created toallocate the value zero (0) formaintain the QoS profiledefined in this document. For any other vendor field, thespecifier values. The specifier fieldis maintained by the vendor. Forindicates theIANA maintainedactual QoSprofilesprofile. Depending on thefollowing allocation policy is defined:value requested, the action needed to request a new value is: 0 to 511: Standards Action 512 to4095:32767: Specification Required 32768 to 4294967295: Reserved Standards action is required to add, depreciate, delete, or modifyexistingQoS 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 of512-4095.512-32767. This document requests IANA to create such a registry and to allocate the value zero (0) for the QoS profile defined in this document. Alternative vendor-specific QoS profiles can be created and identified with a Enterprise Number taken from the IANA registry created by [RFC2578] 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 a AAA protocol. Security considerations are described in documents using this specification. 7. Acknowledgements The authors would like to thank the NSISQSPEC [I-D.ietf-nsis-qspec] authors (Corneliaworking group members Cornelia Kappler, Jerry Ash, Attila Bader, and DaveOran),Oran, the former NSIS working group chairs (John Loughney and Martin Stiemerling) and the former Transport Area Directors (Allison Mankin, Jon Peterson) for their help.The authors of this document are thankful for the suggestions and input received from the NSIS QSPEC [I-D.ietf-nsis-qspec] authors.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 theirhelp with resolving problemsfeedback regarding some of theAdmission Priority and the ALRP parameter.parameters in this documents. Jerry Ash, Al Morton, Mayutan Arumaithurai and Xiaoming Fu provided help with the semantic 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 and Pasi Eronen provided feedback during the IESG review. 8. References 8.1. Normative References[I-D.ietf-tsvwg-emergency-rsvp] Faucheur, F., Polk, J., and K. Carlberg, "Resource ReSerVation Protovol (RSVP) Extensions for Emergency Services", draft-ietf-tsvwg-emergency-rsvp-09 (work in progress), October 2008.[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2210] Wroclawski, J., "The Use of RSVP with IETF Integrated Services", RFC 2210, September 1997. [RFC2215] Shenker, S. and J. Wroclawski, "General Characterization Parameters for Integrated Service Network Elements", RFC 2215, September 1997. [RFC2474] 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. [RFC2578] McCloghrie, K., Ed., Perkins, D., Ed., and J. Schoenwaelder, Ed., "Structure of Management Information Version 2 (SMIv2)", STD 58, RFC 2578, April 1999.[RFC2597] Heinanen, J., Baker, F., Weiss, W., and J. Wroclawski, "Assured Forwarding PHB Group", RFC 2597, June 1999.[RFC3140] Black, D., Brim, S., Carpenter, B., and F. Le Faucheur, "Per Hop Behavior Identification Codes", RFC 3140, June 2001.[RFC3181] Herzog, S., "Signaled Preemption Priority Policy Element", RFC 3181, October 2001. [RFC4124] Le Faucheur, F., "Protocol Extensions for Support of Diffserv-aware MPLS Traffic Engineering", RFC 4124, June 2005. [RFC4412] Schulzrinne, H.[RFC3588] Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J.Polk, "Communications Resource Priority for the Session Initiation Protocol (SIP)",Arkko, "Diameter Base Protocol", RFC4412, February 2006.3588, September 2003. 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.[RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z., and W. Weiss, "An Architecture for Differentiated Services", RFC 2475, December 1998. [RFC2597] Heinanen, J., Baker, F., Weiss, W., and J. Wroclawski, "Assured Forwarding PHB Group", RFC 2597, June 1999. [RFC2697] Heinanen, J. and R. Guerin, "A Single Rate Three Color Marker", RFC 2697, September 1999.[RFC3290] Bernet, Y., Blake,[RFC3246] Davie, B., Charny, A., Bennet, J., Benson, K., Le Boudec, J., Courtney, W., Davari, S.,Grossman, D.,Firoiu, V., andA. Smith,D. Stiliadis, "AnInformal Management Model for Diffserv Routers",Expedited Forwarding PHB (Per-Hop Behavior)", RFC3290, May3246, March 2002.[RFC3564] Le Faucheur, F.[RFC3260] Grossman, D., "New Terminology andW. Lai, "Requirements for Support of Differentiated Services-aware MPLS Traffic Engineering", RFC 3564, July 2003. [RFC5226] Narten, T. and H. Alvestrand, "GuidelinesClarifications forWriting an IANA Considerations Section in RFCs", BCP 26,Diffserv", RFC5226, May 2008.3260, April 2002. 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