1、 AMERICAN NATIONAL STANDARD FOR TELECOMMUNICATIONS ATIS-0100022.2008(R2013) Priority Classification Levels for Next Generation Networks As a leading technology and solutions development organization, ATIS brings together the top global ICT companies to advance the industrys most-pressing business pr
2、iorities. Through ATIS committees and forums, nearly 200 companies address cloud services, device solutions, emergency services, M2M communications, cyber security, ehealth, network evolution, quality of service, billing support, operations, and more. These priorities follow a fast-track development
3、 lifecycle from design and innovation through solutions that include standards, specifications, requirements, business use cases, software toolkits, and interoperability testing. ATIS is accredited by the American National Standards Institute (ANSI). ATIS is the North American Organizational Partner
4、 for the 3rd Generation Partnership Project (3GPP), a founding Partner of oneM2M, a member and major U.S. contributor to the International Telecommunication Union (ITU) Radio and Telecommunications sectors, and a member of the Inter-American Telecommunication Commission (CITEL). For more information
5、, visit. AMERICAN NATIONAL STANDARD Approval of an American National Standard requires review by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by the standards developer. Consensus is established when, in the judgment of the ANSI Board of Standa
6、rds Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made towards t
7、heir resolution. The use of American National Standards is completely voluntary; their existence does not in any respect preclude anyone, whether he has approved the standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standar
8、ds. The American National Standards Institute does not develop standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the America
9、n National Standards Institute. Requests for interpretations should be addressed to the secretariat or sponsor whose name appears on the title page of this standard. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Stand
10、ards Institute require that action be taken periodically to reaffirm, revise, or withdraw this standard. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute. Notice of Disclaimer Security-related a
11、spects; Emergency communications-related aspects; and Coding (e.g., video and speech), at and between carrier-to-carrier and carrier-to-customer interfaces, with due consideration of end-user applications. Standards, requirements, technical reports, and contributions will be developed that: Identify
12、 and define performance parameters and levels for the speed, accuracy, dependability, availability, and robustness of connection establishment, information transfer, and connection disengagement; Define measurement techniques for these performance parameters; Define methods for characterizing networ
13、k and signal processing performance for customer applications; Develop transmission planning guidance for the deployment of signal processing devices such as echo cancellers and VoIP elements; and Take into account the characteristics of signal processing and multimedia systems and the needed interw
14、orking among network technologies and services such as IP, Frame Relay, ATM, SONET, OTN, TDM, Wireless, etc. ANSI guidelines specify two categories of requirements: mandatory and recommendation. The mandatory requirements are designated by the word shall and recommendations by the word should. Where
15、 both a mandatory requirement and a recommendation are specified for the same criterion, the recommendation represents a goal currently identifiable as having distinct compatibility or performance advantages. Suggestions for improvement of this document are welcome. They should be sent to the Allian
16、ce for Telecommunications Industry Solutions, PRQC Secretariat, 1200 G Street NW, Suite 500, Washington, DC 20005. At the time of initiation or issuance of the letter ballot for this document, PRQC, which was responsible for its development, had the following roster: M. Neibert, PRQC Chair N. Seitz,
17、 PRQC Vice-Chair C. Underkoffler, ATIS Chief Editor P. Tarapore, PRQC Technical Editor Organization Represented Name of Representative Alcatel-Lucent Ken Biholar Tim Pantalis (Alt) AT&T Percy Tarapore Charles A. Dvorak (Alt.) Department of Defense Chris Fitzgerald Embarq Corporation Carl M. Coppage
18、John M. Heinz (Alt) Organization Represented Name of Representative Ericsson Incorporated Mustafa Kocaturk Susana Sabater-Maroto (Alt.) ETRI Tae-Soo Chung Sung-Soo Kang (Alt) Huawei Xuewen Gong National Communications System An Nguyen Carol-Lyn Taylor (Alt.) ATIS-0100022.2008 iii Organization Repres
19、ented Name of Representative NTIA Neal B. Seitz Arthur Webster (Alt). Nokia Siemens Networks Nagaraja Rao David E. Francisco (Alt) Nortel Joseph A . Zebarth Qwest Steve Showell Michael Fargano (Alt.) Organization Represented Name of Representative Sprint Steve Oliva Telcordia Technologies Spilios Ma
20、kris Cliff Halevi (Alt.) TELUS Geoff Telfer Lee Himbeault (Alt) Verizon Communications John Colombo Wendy Pugh (Alt.) The PRQC QoS Working Group, which was responsible for the development of this document, had the following members: N. Seitz, QoS Chair P. Tarapore, QoS Technical Editor Active Partic
21、ipants: J. Bennett G. Choudhury C. Dvorak R. Holley Y. Kogan S. Makris A. McCain A. Morton M. Niebert A. Nguyen E. Rojek N. Seitz P. Tarapore A. Webster ATIS-0100022.2008 iv TABLE OF CONTENTS 1 SCOPE & PURPOSE 1 2 REFERENCES 1 2.1 NORMATIVE REFERENCES 1 2.2 INFORMATIVE REFERENCES . 2 3 DEFINITIONS.
22、2 4 ACRONYMS & ABBREVIATIONS . 2 5 OVERVIEW. 2 6 ADMISSION CONTROL PRIORITY CLASSIFICATION LEVELS. 3 7 SERVICE RESTORATION PRIORITY CLASSIFICATION LEVELS. 4 AMERICAN NATIONAL STANDARD ATIS-0100022.2008 American National Standard for Telecommunications Priority Classification Levels for Next Generati
23、on Networks 1 1 SCOPE & PURPOSE According to ITU-T Recommendation Y.1271 Y.1271, enhanced priority treatment is an essential requirement for the assured capabilities needed for Emergency Telecommunications Service (ETS). Two critical components of enhanced priority treatment are: Admission control f
24、or telecommunications services seeking entry into a network particularly during emergency conditions when network resources may be depleted. Network restoration for telecommunications services that are in progress when the network experiences an outage resulting in depleted resources. These componen
25、ts in a Next Generation Network (NGN) can be enabled by: 1. Development of admission control and restoration priority levels based on the criticality of services seeking entry in NGNs and service restoration. 2. Development of necessary extensions in signaling protocols that can indicate the desired
26、 service priority levels at NGN interfaces. 3. Development of admission control and restoration mechanisms that can recognize the signaled priority levels and undertake necessary action. The scope of this document is limited to formalizing priority classification levels for admission control and ser
27、vice restoration (step 1). The purpose is to initiate an examination of existing signaling protocol extensions to determine their adequacy in supporting priority levels and to recommend further action as needed. 2 REFERENCES 2.1 Normative References The following standards contain provisions which,
28、through reference in this text, constitute provisions of this American National Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this American National Standard are encouraged to investigate the possibi
29、lity of applying the most recent editions of the standards indicated below. ITU-T Y.1271, Framework(s) on network requirements and capabilities to support emergency telecommunications over evolving circuit-switched and packet-switched networks.1ITU-T Y.2171, Admission control priority levels in Next
30、 Generation Networks.11This document is available from the International Telecommunications Union. ATIS-0100022.2008 2 ITU-T Y.2172, Service restoration priority levels in Next Generation Networks.12.2 Informative References ATIS-0100003, User Plane Priority Levels for IP Networks and Services.2ATIS
31、-0100006, Service Restoration Priority Levels for IP Networks.23 DEFINITIONS 3.1 Admission Control: A set of actions/policies taken by the network at session set-up phase in order to accept or reject a service based on requested performance and priority criteria and the availability of necessary res
32、ources. 3.2 Service Restoration: A set of automated or manual methods, invoked after a network failure, to enhance the ability of successful communications reroute and completion around the failed network element(s). 4 ACRONYMS & ABBREVIATIONS ANS American National Standard CAC Connection Admission
33、Control ETS Emergency Telecommunications Service G-MPLS Generalized MPLS IP Internet Protocol ISP Internet Service Provider ITU-T International Telecommunications Union - Telecommunication Standardization Sector MPLS Multi-Protocol Label Switching NGN Next Generation Network PRQC Performance Reliabi
34、lity and Quality of Service Committee QoS Quality of Service SLA Service Level Agreement VoIP Voice over IP VPN Virtual Private Network 5 OVERVIEW NGNs are expected to be truly “converged” - that is, all forms of telecommunications services will be handled by such networks: control plane traffic (e.
35、g., routing messages), emergency telecommunications, real-time voice and video services, data services, Virtual Private Network (VPN) 2This document is available from the Alliance for Telecommunications Industry Solutions (ATIS), 1200 G Street N.W., Suite 500, Washington, DC 20005. ATIS-0100022.2008
36、 3 services, as well as traditional “best effort” traffic. In such an environment, it is important to assign priority levels and establish rules for capacity reservation /admission and service restoration such that: Critical services are recognized and accepted for call/session setup and admission (
37、or simply carried in the case of non-session oriented traffic) over other services in case of network overloads or failures. Critical service calls/sessions that are in progress when network failures occur receive restoration priority treatment over other services under such conditions (e.g., deplet
38、ed resources and bandwidth). As services can be expected to traverse multiple network domains, setting priority classification levels is an important step in the development of the necessary signaling protocol extensions as well as the mechanisms for enabling preferential admission and restoration t
39、reatment of critical services. An NGN must recognize and admit higher priority services into the network, particularly under failure and/or congestion conditions. This can be referred to as a traditional form of Connection Admission Control (CAC) priority classification. The need for such priority l
40、evels is most critical under emergency conditions when networks may experience loss of resources and capacity coupled with surges of communications traffic as the impacted public seeks help (in the affected areas) or information about family and friends. Priority levels can then be utilized by CAC f
41、unctions to determine whether incoming calls or sessions can be admitted depending on the criticality of the service and the availability of a potentially reduced set of network resources. Note that the priority level recommendations proposed in this document strictly relate to the relative importan
42、ce of telecommunications services seeking admission into networks. They do not reflect implementation specific priority definitions. Further, these recommended levels are independent from the ITU-T Recommendation Y.1541 QoS3classes. Restoration priority classification is based on the following premi
43、se: Under reduced bandwidth conditions resulting from network failure, the critical issue for an NGN is the ability to recognize and restore higher priority traffic flows first. The priority level recommendations proposed in this document strictly relate to the relative importance of traffic classes
44、 from this perspective. They do not reflect implementation-specific priority definitions. For example, there are mechanisms utilizing Generalized Multi-Protocol Label Switching (G-MPLS)-based recovery that define specific recovery capabilities such as 1+1 protection and 1:N protection as described i
45、n IETF RFC 44264. Such mechanism-specific priority definitions do not apply to the recommendations in this document. To summarize, the priority classification levels being recommended in this document are completely independent of the enabling mechanisms that a network operator may utilize. 6 ADMISS
46、ION CONTROL PRIORITY CLASSIFICATION LEVELS Three admission control priority levels are recommended for telecommunications services seeking entry into NGN: 3ITU-T Recommendation Y.1541, Network performance objectives for IP-based services. 4IETF RFC 4426, Generalized Multi-Protocol Label Switching (G
47、-MPLS) Recovery Functional Specification. ATIS-0100022.2008 4 Priority Level 1 (High Priority): Traffic with this priority level receives the highest assurance for admission to the network. This level is reserved for emergency telecommunications (e.g., ETS and E911) over NGN. Priority Level 2 (Norma
48、l Priority): Traffic with this priority level will not receive the same assurance for admission as that given to Priority Level 1 traffic, but will receive higher assurance for admission than that given to Priority Level 3 traffic. Examples include real-time services (VoIP, video), VPN, and data ser
49、vices. The selection of this priority level is expected to be determined by appropriate Service Level Agreements (SLA) between network operators and customers for the desired service. Priority Level 3 (Best Effort Priority): Traffic with this priority level receives the least assurance for admission to the network. Examples include “traditional” Internet Service Provider (ISP) services (e-mail, web surfing). The selection of this priority level is expected to be determined by appropriate SLA agreements between network operators and custome
