Network Working Group Jerry Ash Internet Draft AT&T Attila Bader Expiration Date: April 2005 Ericsson Cornelia Kappler Siemens AG October 2004 QoS-NSLP QSpec Template Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of RFC 3668. 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) The Internet Society (2004). All Rights Reserved. Abstract The QoS NSLP protocol is used to signal QoS reservations and is independent of a specific QoS model such as IntServ or DiffServ. Rather, all information specific to QoS models is encapsulated in a separate object, the QSpec. This draft defines a template for the QSpec, which contains both the QoS description and control information specific to a given QoS model. The QSpec format is defined as are a number of generic and optional parameters. Generic parameters provide a common language to be re-used in several QoS models, which are derived initially from the IntServ and DiffServ QoS models. Optional parameters aim to ensure the extensibility of QoS NSLP to other QoS models. Ash et al. Expires - April 2005 [Page 1] Internet Draft QoS-NSLP QSpec Template October 2004 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . .2 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Applicability. . . . . . . . . . . . . . . . . . . . . . . . . .4 3.1 Processing of QSpec. . . . . . . . . . . . . . . . . . . . . . 4 3.2 Generic Parameters. . . . . . . . . . . . . . . . . . . . . . .5 3.3 Extensibility. . . . . . . . . . . . . . . . . . . . . . . . . 5 4. QSpec Format Overview. . . . . . . . . . . . . . . . . . . . . .6 4.1 QSP Specific Control Information. . . . . . . . . . . . . . . .6 4.2 QoS Description. . . . . . . . . . . . . . . . . . . . . . . . 7 4.2.1 QoS Desired. . . . . . . . . . . . . . . . . . . . . . . . . 8 4.2.2 QoS Available. . . . . . . . . . . . . . . . . . . . . . . . 8 4.2.3 QoS Reserved. . . . . . . . . . . . . . . . . . . . . . . . .9 4.2.4 Minimum QoS. . . . . . . . . . . . . . . . . . . . . . . . . 9 5. Security Considerations. . . . . . . . . . . . . . . . . . . . .9 6. Open Issues. . . . . . . . . . . . . . . . . . . . . . . . . . 10 7. Acknowledgements. . . . . . . . . . . . . . . . . . . . . . . .10 8. Intellectual Property Considerations. . . . . . . . . . . . . .10 9. References. . . . . . . . . . . . . . . . . . . . . . . . . . .11 10. Authors' Addresses. . . . . . . . . . . . . . . . . . . . . . 11 Appendix A Example Qspecs. . . . . . . . . . . . . . . . . . . . .13 A.1 QSpec for Admission Control for DiffServ. . . . . . . . . . . 13 A.2 QSpec for IntServ Controlled Load Service. . . . . . . . . . .13 A.3 QSpec for IntServ Guaranteed Services. . . . . . . . . . . . .14 Appendix B QoS Models, QoS Signaling Policies and QSpecs. . . . . 14 Appendix C Mapping of QoS Desired, QoS Available, and QoS Reserved of NSIS onto AdSpec, TSpec, and RSpec of RSVP IntServ. . . . . . .15 Copyright Statement. . . . . . . . . . . . . . . . . . . . . . . .16 Disclaimer of Validity and Copyright Statement. . . . . . . . . . 16 1. Introduction The QoS NSLP establishes and maintains state at nodes along the path of a data flow for the purpose of providing forwarding resources (QoS) for that flow [QoS-SIG]. The design of QoS NSLP is conceptually similar to RSVP [RSVP], and meets the requirements of [NSIS-REQ]. QoS NSLP can signal for different QoS Models, i.e. QoS provisioning methods or QoS architectures. It should be able to support, for example, IntServ and signaling for DiffServ admission control, and satisfy the need of more complex control planes such as defined in [Q.2630, Y.1541]. The use of QoS NSLP to signal for a specific QoS Model is called a 'QoS Signaling Policy' (QSP). Examples of different QSPs for NSIS are specified in [TRQ-QoS-SIG, INTSERV-QoS-SIG, RMD- QoS-SIG]. For more information on QoS Models and QSPs see Appendix B. QSP-specific information is carried in the so-called QSpec object, which travels in QoS-NSLP messages. The format of the QSpec object is QSP specific. The QSpec is opaque to QoS NSLP. It contains two types of information: QSP Control Information and a QoS Description. Ash et al. Expires - April 2005 [Page 2] Internet Draft QoS-NSLP QSpec Template October 2004 The QSP control information contains information not related to the actual resource management but rather to message processing. An example of QSP control information is the scope of the QSpec. QSP Control Information must not be confused with the Common Control Information, which is a set of objects defined in QoS NSLP. Whereas QSP Control Information is specific to the QSpec, Common Control Information is specific to the QoS NSLP message. The QoS Description is composed of objects corresponding to the TSpec, RSpec and AdSpec objects specified in RSVP. This is, the QSpec may contain a description of QoS desired and QoS reserved. It can also collect information about available resources. Going beyond RSVP functionality, the QoS Description also allows indicating a range of acceptable QoS by defining an object denoting minimum QoS. Usage of these objects is not bound to particular message types thus allowing for flexibility. An object collecting information about available resources may travel in any QoS NSLP message, for example a QUERY message or a RESERVE message. This draft provides a template for the QSpec, which is needed in order to help defining individual QSPs and in order to promote interoperability between QoS models. The applicability of the QSpec is discussed in Section 3. The QSpec template is given in Section 4. Section 5 gives security considerations. Appendix A proposes QSpecs for the IntServ Controlled Load and Guaranteed Service QoS Models. Appendix B explains in more detail the relation between QoS Models, QSPs and QSpecs. It also explains the current understanding of the content of a QSP. Appendix C explains how the objects defined for the QSpec map onto the corresponding TSpec, AdSpec and RSpec of RSVP. 2. Terminology Common NSLP Processing: Functions in a QNE that are related to NSLP message processing (common for each QoS Model) Generic Parameter: Parameter that MUST be understood by any QNE, and SHOULD be used if applicable Read-only Parameter: Parameter that is set by initiating or responding QNE and is not changed during the processing of QSpec along the path Minimum QoS: Minimum QoS is a functionality that MAY be supported by any QSP: Together with a description of desired QoS, it allows the QNI to specify a QoS range, i.e. an upper and lower bound. If the desired QoS is not available, QNFs are going to decrease the reservation until the minimum QoS is hit. Read-write Parameter: Parameter that can be changed during the processing of QSpec by any QNE along the path Optional Parameter: Parameter that SHOULD be used by QSPs if applicable Ash et al. Expires - April 2005 [Page 3] Internet Draft QoS-NSLP QSpec Template October 2004 QoS Description: Describes the actual QoS being reserved. May contain the objects QoS Desired, QoS Available, QoS Reserved and Minimum QoS. These objects are input or output parameters of the Resource Management Function QoS Available: Object containing parameters describing the available resources. They are used to collect information along a reservation path. QoS Desired: Object containing parameters describing the desired QoS and/or the traffic for which the sender request reservation. QoS Model: A methodology to achieve QoS for a traffic flow, e.g. IntServ Controlled Load. QoS Reserved: Object containing parameters describing the reserved resources and related QoS parameters (e.g. Slack Term) QoS Signaling Policy (QSP): A signaling policy describing how to use QoS NSLP to signal for a specific QoS Model QSpec Control Information: Control information that is specific to a QSpec, and processed in QSpec-specific NSLP Processing. QSpec-specific NSLP Processing: Functions in a QNE that process QSP Control Information and are specific to each QoS Model. QSpec: QSpec is the object of QoS-NSLP containing all QoS Model specific information. QSpec parameter: any parameter appearing in a QSpec, for example, scope of QSpec or token bucket. QSpec object: Main building blocks of QoS Description containing a parameter set that is input or output of a Resource Management Function operation. Resource Management Function: Functions that are related to resource management, specific to a QoS Model. It processes QoS Description. 3. Applicability 3.1 Processing of QSpec The QSpec is opaque to the QoS-NSLP processing. The QSpec control information is interpreted and perhaps modified by the QSpec-specific NSLP processing, and the QoS description is interpreted and may be modified by the Resource Management Function (see Figure 1 and description in [QoS-SIG]). Ash et al. Expires - April 2005 [Page 4] Internet Draft QoS-NSLP QSpec Template October 2004 3.2 Generic Parameters The QSpec template defines a format for the QSpec, as well as a number of generic and optional QSpec parameters. Generic parameters provide a common language for QSP developers to build their QSpecs and are likely to be re-used in several QSPs. This eases comparing different QSpecs and different QSPs - and possibly simplifies mapping of one into another. Thus developers should avoid defining proprietary parameters equivalent to the generic, standardized ones. All parameters used in DiffServ and IntServ QSPs are generic parameters. A specific QSP may, however, only use a subset or perhaps none of the generic QSpec parameters. For instance, it may only allow the token bucket to be specified. Furthermore, a QSP may define additional parameters. In any event, generic parameters SHOULD be used by QSPs if applicable. The Resource Management Function (RMF) in all QNEs must be able to understand the generic parameters. This means a Resource Management Function is not restricted in how the traffic conditioning of a particular generic parameter is implemented. It MUST however be able to provide a meaningful implementation of generic parameters. Additionally, when QoS properties of a path are collected, a RMF must be able to give a meaningful answer. For example, when a RESERVE message carries a QSpec with a token bucket, the RMF must be able to update the token bucket parameters according to what it is able to provide, even if it does not implement a token bucket. A QSpec is specific to a QSP and is identified by a QSP ID carried in QoS NSLP. However, as explained above, the generic parameters contained in a QSpec are understood by any QNE, even if the corresponding QSP is not known. Therefore a QNE SHOULD interpret the generic parameters contained in a QSpec, even if it does not understand the QSP. I.e. an unknown QSP should not lead to abortion of the signaling message, or to not passing the QSpec to the RMF. QoS NSLP provides the error code ôUnknown QSPö to indicate only generic parameters were interpreted. Hence, generic parameters ease global intelligibility of QoS NSLP messages. 3.3 Extensibility A specific QSP may need more parameters than the generic ones. The QSpec Template allows additional types of parameters, namely optional parameters. Optional parameters are parameters that are likely to occur in many QSPs, which however are necessary neither for the DiffServ nor the IntServ QoS Model (because parameters needed for these QoS Models are by definition generic parameters). Future versions of this draft will define a number of optional parameters, e.g. for measuring delay. Ash et al. Expires - April 2005 [Page 5] Internet Draft QoS-NSLP QSpec Template October 2004 Optional parameters SHOULD be used by QSPs if applicable to facilitate interworking. However, QNEs outside the domain employing a particular QSP cannot be expected to understand the optional parameters. 4. QSpec Format Overview QSpec = As described above, the QSpec object contains the actual resource description (QoS description) as well as QSpec control information. Both QoS description and QSpec control information may contain read-write and read-only objects. Read-write objects can be changed by any QNE, including by QoS NSIS functions along the signaling path, whereas read-only objects are fixed by the initiating QNE and/or responding QNEs. An example of a read-write object is the QoS Available, which is updated by intermediate QNEs. An example of an read-only object is QoS Desired as sent by theQNI. 4.1. QSP Specific Control Information QSP specific control information is used for QSpec-specific control information and for specific signaling functions not defined in QoS- NSLP. It enables building a new signaling policy within a QoS-NSLP signaling framework, see for example [RMD-QoS-SIG] and [RMD-QSP]. Generic parameters: - read-write hop count field, limiting the scope of QSpec to a maximum number of QoS-NSLP hops. must not be confused with the scope of the QoS NSLP message carrying the QSpec. This scope would be coded in the Common Control Information. - = , | Read-only parameter, indicating the desired start time and end time of the service, i.e. when is the service available. The values for and respectively can be infinity, in which case the reservation can be ended by the usual tearing RESERVE. The Service Schedule parameter has two-fold use: a. Reservation of resources for the immediate future when the full flow ID is still being negotiated (e.g. port number may be negotiated with SIP). In this case is set to zero. Ash et al. Expires - April 2005 [Page 6] Internet Draft QoS-NSLP QSpec Template October 2004 b. Scheduling of reservations ahead of time to make sure resources will be available, i.e. a Reserve / Commit functionality. An example is reservation of resources for a video-conference. Also in this case the full flow ID, e.g. port numbers, may not be known at the time of reservation. Hence, in both cases the QNI sends an incomplete RESERVE prompting the Resource Management Function to set aside resources without actually configuring the router(s). Router configuration is triggered by a RESERVE containing the full flow ID. It needs to be considered whether Service Schedule should be an optional parameter because supporting it involves some overhead: the RMF needs functionality to set aside resources in advance and configure the router(s) later. Furthermore, for large advance reservations, it may be necessary to "phase out" ongoing reservations much earlier than the actual reservation in order to make sure resources will be available. Note that even reservations that are "scheduled" need to be refreshed just as ongoing reservations. Refresh periods are specific to a particular state in a particular QNE [QoS-SIG]. Hence it is conceivable that QNEs decide locally to make the refresh period for scheduled reservations considerably longer than that for ongoing reservations. 4.2 QoS Description The QoS Description is broken down into the following objects: = Of these objects, QoS Desired and Minimum QoS are read-only, whereas QoS Available and QoS Reserved are read-write. If it needs to be Ensured that QoS Desired and Minimum QoS are indeed not changed along the path, it is possible to apply selective protection of these objects only. The verification is based on cryptographic procedures. On the QSpec template level, the only restriction on object usage is that should always travel together with and/or . Otherwise there is no restriction on how many of these objects a QSpec may carry, nor what type of object is carried in what type of QoS NSLP message. For example, in a receiver-initiated reservation scenario, the initiating QNE may send a QUERY carrying a object to probe the available resources on the path. The same QUERY may carry a object. The responding QNE can re-use the latter objects in the RESERVE message. The QoS NSLP and particularly the QSPs prescribe how the objects in QSpecs are interpreted and used, and therefore restrict this freedom. Ash et al. Expires - April 2005 [Page 7] Internet Draft QoS-NSLP QSpec Template October 2004 The union of all the objects identified in this Section can provide all functionality of the objects specified in RSVP IntServ. QoS Desired may in fact just be a description of traffic to be sent, but it may also include more parameters (e.g. delay) or signal for more resources than those derived from an exact traffic description (e.g. a token bucket with a higher peak rate). Furthermore all objects can carry the same parameter types. Hence, a QNI could send a RESERVE with QoS Desired contained a particular Average bandwidth, and at the same time include a QoS Available Object for querying availability of this same parameter. If QoS Desired cannot be reserved, the QNR can use the information Collected in QoS Available along the path to signal back to the QNI a more promising value of QoS Desired. The details of such Message exchanges are fixed in [QoS-Sig]. 4.2.1 = These parameters describe the resources the QNI desires to reserve and hence this is an read-only object. QoS Desired may be an accurate description of the traffic the QNI is going to inject into the network. It may however also ask for more (or less) resources. Note that QoS Desired may also carry other parameters like desired delay or loss parameters, however these are optional parameters and not specified in this document. = the share of the linkÆs bandwidth the flow is entitled to (see RFC 2212) =

as defined in [RFC 2210] = An application may like to reserve resources for packets with a particular QoS class, e.g. a DiffServ per-hop behavior (PHB) [DIFFSERV, DCLASS], or DiffServ-enabled traffic engineering (DS-TE) class type [DS-TE]. = Reservation priority is an essential way to differentiate flows for emergency services, ETS, E911, etc., and assign them a higher priority than normal priority flows. Appropriate security measures need to be taken to prevent abuse of this parameter. These are read-only parameters. 4.2.2 = Ash et al. Expires - April 2005 [Page 8] Internet Draft QoS-NSLP QSpec Template October 2004 These parameters describe the resources currently available on the path and hence the object is read-write. They are defined in [RFC 2210, 2212, 2215]. and are the number of QSP aware and non QSP aware nodes along the path. Each QNE must inspect this object. If resources available to this QNE are less than what says currently, the QNE must adapt it accordingly. Hence when the message arrives at the recipient of the message, reflects the bottleneck of the resources currently available on a path. It can be used in a QUERY message, for example, to collect the available resources along a data path. 4.2.3 = These parameters describe the QoS reserved by the QNEs down the path. , , and are defined above. is defined in [RFC 2212]. This is a read-write object. 4.2.4 = , , , and are defined above doesn't have an equivalent in RSVP. It allows the QNI to define a range of acceptable QoS levels by including both the desired QoS value and the minimum acceptable QoS in the same message. It is an read-only object. The desired QoS is included with a and/or a object seeded to the desired QoS value. The minimum acceptable QoS value is coded in the object. As the message travels towards the QNR, is updated by QNEs on the path. If its value drops below the value of the reservation failed and can be aborted. When this method is employed the QNR SHOULD signal back to the QNI the value attained in the end, because the reservation may need to be adapted accordingly. 5. Security Considerations The Service Schedule parameter raises possibilities for Denial of Service Attacks because an attacker could signal a QNE to set aside resources without ever completing the reservation. This is prevented by charging incomplete / pending reservations. The priority parameter raises possibilities for Theft of Service Attacks because users could claim an emergency priority for their flows without real need, thereby effectively preventing serious emergency calls to get through. Several options exist for countering such attacks, for example - only some user groups (e.g. the police) are authorized to set the emergency priority bit Ash et al. Expires - April 2005 [Page 9] Internet Draft QoS-NSLP QSpec Template October 2004 - any user is authorized to employ the emergency priority bit for particular destination addresses (e.g. police) 6. Open Issues a. Clarify the relationship of Common NSLP Processing, QSP-specific NSLP Processing and the Resource Management Function. b. Specify optional parameters proposed to support other QSPs. c. Should Service Schedule be an optional parameter because of the overhead it may introduce? d. Are proprietary QSpec parameters required? e. Is a flag needed to indicate when a QNE cannot process a given generic parameter? f. Should PHB explicitly signaled in PHB-DCLASS? g. The bit-level format for the QoS objects and QoS parameters needs to be defined 7. Acknowledgements The authors would like to thank Robert Hancock, Sven van den Bosch, and Hannes Tschofenig for their helpful suggestions. 8. Intellectual Property Considerations The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf- ipr@ietf.org. Ash et al. Expires - April 2005 [Page 10] Internet Draft QoS-NSLP QSpec Template October 2004 9. References [DIFFSERV] S. Blake et. al., "An Architecture for Differentiated Services", RFC 2475, December 1998. [DS-TE] F. Le Faucheur et. al., Requirements for Support of Differentiated Services-aware MPLS Traffic Engineering, RFC 3564, July 2003 [KEY] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997 [INTSERV] B. Braden et. al., "Integrated Services in the Internet Architecture: an Overview," RFC 1633, June 1994. [INTSERV-QoS-SIG] C. Kappler, "A QoS Model for Signaling IntServ Controlled-Load Service with NSIS," work in progress. [NSIS-REQ] M. Brunner et. al., "Requirements for QoS Signaling Protocols", work in progress. [RFC2211] J. Wroclawski, "Specification of the Controlled-Load Network Element Service", RFC 2211, Sept. 1997. [RFC2212} Shenker, S., et. al., "Specification of Guaranteed Quality of Service," September 1997. [RFC2215] S. Shenker and J. Wroclawski, "General Characterization Parameters for Integrated Service Network Elements", RFC 2215, Sept. 1997. [RMD-QoS-SIG] A. Bader et. al., "RMD (Resource Management in Diffserv) QoS-NSLP model", work in progress. [RMD-QSP] A. Bader, L. Westberg, G. Karagiannis, C. Kappler and T. Phelan, " RMD-QSP: An NSIS QoS Signaling Policy model for Networks Using Resource Management in Diffserv (RMD)" , work in progress. [RSVP] B. Braden et. al., "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification," RFC 2205, September 1997. [RSVP-INTSERV] J. Wroclawski, "The Use of RSVP with IETF Integrated Services", RFC 2210, September 1997. [TRQ-QoS-SIG] J. Ash et. al., "NSIS Network Service Layer Protocol QoS Signaling Proof-of-Concept," work in progress. [QoS-SIG] S. Van den Bosch et. al., "NSLP for Quality-of-Service Signaling," work in progress. [Y.1541] ITU-T Recommendation Y.1541, "Network Performance Objectives for IP-Based Services," May 2002. [Q.2630] ITU-T Recommendation Q.2630.3: "AAL Type 2 Signaling Protocol - Capability Set 3" Sep. 2003 [DCLASS] Bernet Y., Format of the RSVP DCLASS Object, RFC 2996, November 2000 10. Authors' Addresses Jerry Ash AT&T Room MT D5-2A01 200 Laurel Avenue Middletown, NJ 07748, USA Phone: +1-(732)-420-4578 Fax: +1-(732)-368-8659 Email: gash@att.com Ash et al. Expires - April 2005 [Page 11] Internet Draft QoS-NSLP QSpec Template October 2004 Attila Bader Traffic Lab Ericsson Research Ericsson Hungary Ltd. Laborc u. 1 H-1037 Budapest Hungary EMail: Attila.Bader@ericsson.com Chuck Dvorak AT&T Room 2A37 180 Park Avenue, Building 2 Florham Park, NJ 07932 Phone: + 1 973-236-6700 Fax:+1 973-236-7453 E-mail: cdvorak@att.com Yacine El Mghazli Alcatel Route de Nozay 91460 Marcoussis cedex FRANCE Phone: +33 1 69 63 41 87 Email: yacine.el_mghazli@alcatel.fr Cornelia Kappler Siemens AG Siemensdamm 62 Berlin 13627 Germany Email: cornelia.kappler@siemens.com Georgios Karagiannis University of Twente P.O. BOX 217 7500 AE Enschede The Netherlands EMail: g.karagiannis@ewi.utwente.nl Andrew McDonald Siemens/Roke Manor Research Roke Manor Research Ltd. Romsey, Hants SO51 0ZN, UK EMail: andrew.mcdonald@roke.co.uk Al Morton AT&T Room D3-3C06 200 S. Laurel Avenue Middletown, NJ 07748 Phone: + 1 732 420-1571 Fax: +.1 732 368-1192 E-mail: acmorton@att.com Ash et al. Expires - April 2005 [Page 12] Internet Draft QoS-NSLP QSpec Template October 2004 Percy Tarapore AT&T Room D1-3D33 200 S. Laurel Avenue Middletown, NJ 07748 Phone: + 1 732 420-4172 E-mail: tarapore@.att.com Lars Westberg Ericsson Research Torshamnsgatan 23 SE-164 80 Stockholm, Sweden EMail: Lars.Westberg@ericsson.com Appendix A: Example QSpecs Note the mere definition of QSpecs is not sufficient for determining how to signal for DiffServ and IntServ respectively. Rather, the full QSP needs to be defined. A.1 QSpec for Admission Control for DiffServ QSpec for Diffserv QSP in general may be provided in future versions of this draft. A QSpec for a DiffServ QSP, RMD is partically included in [RMD-QSP]. A.2 QSpec for IntServ Controlled Load Service The QoS Model for IntServ Controlled Load is defined in [RFC2211]. The QSpec can be derived from usage of RSVP to signal for this QoS Model, as defined in [RSVP-INTSERV] and [RFC2215]. The QSpec for IntServ Controlled Load is composed of the objects and , as well as . Which object is present in a particular QSpec depends on the message type (RESERVE, QUERY etc) in which the QSpec travels. Details must be provided in a corresponding QSP. Parameters in the QSpec are as follows: = = = = An IntServ over Diffserv QSpec is = = = = Ash et al. Expires - April 2005 [Page 13] Internet Draft QoS-NSLP QSpec Template October 2004 Or a simple QSpec for Diffserv requesting bandwidths for different PHBs is = = A.3 QSpec for IntServ Guaranteed Services The QoS Model is defined in [RFC 2212]. The required parameters to achieve guarantied service with RSVP are specified in [RFC 2210] and [RFC 2215]. The QSpec for guarantied services is the following: = = This object contains token bucket parameters defined in [RFC 2210]. Equivalent to TSpec defined in RSVP. = These parameters are defined in [RFC 2212] and [RFC 2215]. This object is equivalent to AdSpec of RSVP. = Requested Rate and Slack Term defined in [RFC 2212], equivalent to RSpec of RSVP. Note that the Guarantied Services QoS Model only works with receiver initiated reservation signaling, because and are derived from parameters contained in , and may be updated on the return paths. Appendix B: QoS Models, QoS Signaling Policies and QSpecs This section gives a description of QoS Models, QSPs and QSpecs and explains what is the relation between them. Once these descriptions are contained in a stable form in the appropriate IDs this Appendix will be removed. QoS NSLP is a generic QoS Signaling Protocol that can signal for many QoS Models. A QoS Model is a particular QoS provisioning method or QoS architecture such a IntServ Controlled Load, Guaranteed Service. DiffServ, or RMD for DiffServ. Ash et al. Expires - April 2005 [Page 14] Internet Draft QoS-NSLP QSpec Template October 2004 The definition of the QoS Model is independent from the definition of QoS NSLP. Existing QoS Models do not specify how to use QoS NSLP to signal for them. Therefore, we need to define the QoS Signaling Policy (QSP), specific to each QoS Model, which describes the QoS Model specific signaling functions. QoS Signaling Policy are defined for "Resource Management in DiffServ" in [RMD-QSP] and for IntServ Controlled Load in [INTSERV-QoS-SIG]. A QSP should include the following information: - Role of QNEs in this QoS Model: E.g. location, frequency, statefulness... - QSpec Definition: A QSP should specify the QSpec, including generic and optional parameters. Furthermore it needs to explain how generic parameters not used in this QSP are mapped onto parameters defined therein. - Message Format Objects to be carried in RESERVE, QUERY RESPONSE and NOTIFY - State Management It describes how QSpec info is treated and interpreted in the Resource Management Function and QSP specific processing. E.g. admission control, scheduling, policy control, QoS parameter accumulation (e.g. delay)? - Operation and Sequence of Events Usage of QoS-NSLP messages to signal the QoS Model. Appendix C: Mapping of QoS Desired, QoS Available and QoS Reserved of NSIS onto AdSpec, TSpec and RSpec of RSVP IntServ The union of QoS Desired, QoS Available and QoS Reserved can provide all functionality of the objects specified in RSVP IntServ, however it is difficult to provide an exact mapping. In RSVP, the Sender TSpec specifies the traffic an application is going to send (e.g. token bucket). The AdSpec can collect path characteristics (e.g. delay). Both are issued by the sender. The receiver sends the FlowSpec which includes a Receiver TSpec describing the resources reserved using the same parameters as the Sender TSpec, as well as a RSpec which provides additional IntServ QoS Model specific parameters, e.g. Rate and Slack. The RSVP TSpec/AdSpec/RSpec seem quite tailored to receiver-initiated signaling employed by RSVP, and the IntServ QoS Model. E.g. to the knowledge of the authors it is not possible for the sender to specify a desired maximum delay except implicitly and mutably by seeding the AdSpec accordingly. Likewise, the RSpec is only meaningfully sent in the receiver-issued RSVP RESERVE message. For this reason our debate at this point lead us to a slightly different mapping of necessary functionality to objects, which should result in more flexible signaling models. Ash et al. Expires - April 2005 [Page 15] Internet Draft QoS-NSLP QSpec Template October 2004 Copyright Statement Copyright (C) The Internet Society (2004). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Disclaimer of Validity This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.