1、 INTERNATIONAL TELECOMMUNICATION UNION ITU-T Y.1310TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2004) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT GENERATION NETWORKS Internet protocol aspects Transport Transport of IP over ATM in public networks ITU-T Recom
2、mendation Y.1310 ITU-T Y-SERIES RECOMMENDATIONS GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT GENERATION NETWORKS GLOBAL INFORMATION INFRASTRUCTURE General Y.100Y.199 Services, applications and middleware Y.200Y.299 Network aspects Y.300Y.399 Interfaces and protocols Y.400Y.4
3、99 Numbering, addressing and naming Y.500Y.599 Operation, administration and maintenance Y.600Y.699 Security Y.700Y.799 Performances Y.800Y.899 INTERNET PROTOCOL ASPECTS General Y.1000Y.1099 Services and applications Y.1100Y.1199 Architecture, access, network capabilities and resource management Y.1
4、200Y.1299 Transport Y.1300Y.1399 Interworking Y.1400Y.1499 Quality of service and network performance Y.1500Y.1599 Signalling Y.1600Y.1699 Operation, administration and maintenance Y.1700Y.1799 Charging Y.1800Y.1899 NEXT GENERATION NETWORKS Frameworks and functional architecture models Y.2000Y.2099
5、Quality of Service and performance Y.2100Y.2199 Service aspects: Service capabilities and service architecture Y.2200Y.2249 Service aspects: Interoperability of services and networks in NGN Y.2250Y.2299 Numbering, naming and addressing Y.2300Y.2399 Network management Y.2400Y.2499 Network control arc
6、hitectures and protocols Y.2500Y.2599 Security Y.2700Y.2799 Generalized mobility Y.2800Y.2899 For further details, please refer to the list of ITU-T Recommendations. ITU-T Rec. Y.1310 (03/2004) i ITU-T Recommendation Y.1310 Transport of IP over ATM in public networks Summary With the rapid growth of
7、 IP-based networks and applications in both private and public networks, it is necessary to consider arrangements to transport IP services over ATM in the public network environment. For the private network environment, the ATM Forum has specified Multi-Protocol Over ATM (MPOA) ATM_MPOA. The Interne
8、t Engineering Task Force (IETF) has specified Classical IP Over ATM (C-IPOA) CIP_ATM and Next Hop Resolution Protocol (NHRP) NHRP and Multi-Protocol Label Switching (MPLS) MPLS_ARCH. To ensure that public networks will interwork with each other supporting a set of services defined in this Recommenda
9、tion, and to ensure the interworking of public and private networks, it is necessary to recommend the preferred approach for transporting IP over ATM in public networks. The approach adopted in this Recommendation is to identify generic requirements, key IP services and determine which IP over ATM a
10、pproach is preferred for each service. It is preferable that the same approach is used for all services considered. This approach is recommended for all identified services using IP over ATM transport in public networks. Source ITU-T Recommendation Y.1310 was approved on 15 March 2004 by ITU-T Study
11、 Group 13 (2001-2004) under the ITU-T Recommendation A.8 procedure. ii ITU-T Rec. Y.1310 (03/2004) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a perma
12、nent organ of ITU. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis. The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establis
13、hes the topics for study by the ITU-T study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covered by the procedure laid down in WTSA Resolution 1. In some areas of information technology which fall within ITU-Ts purview, the necessary standa
14、rds are prepared on a collaborative basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicate both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recom
15、mendation may contain certain mandatory provisions (to ensure e.g. interoperability or applicability) and compliance with the Recommendation is achieved when all of these mandatory provisions are met. The words “shall“ or some other obligatory language such as “must“ and the negative equivalents are
16、 used to express requirements. The use of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROPERTY RIGHTS ITU draws attention to the possibility that the practice or implementation of this Recommendation may involve the use of a claimed Inte
17、llectual Property Right. ITU takes no position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserted by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not recei
18、ved notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementors are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent database. ITU 2004 All rights reserved.
19、 No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. ITU-T Rec. Y.1310 (03/2004) iii CONTENTS Page 1 Scope 1 2 References. 1 2.1 Normative references 1 2.2 Informative references 2 3 Terms and definitions . 3 4 Abbreviations and acrony
20、ms 3 5 Generic requirements 5 6 Framework architecture 5 6.1 Network architecture 6 6.2 Protocol architecture. 8 7 IP services. 10 7.1 Mapping of IP QoS with ATM. 10 7.2 IP Virtual Private Networks (IP-VPNs) . 15 8 Preferred network solution . 17 8.1 Recommended approach 17 8.2 Framework for MPLS ov
21、er ATM in public networks 18 Appendix I Approaches for IP over ATM 20 I.1 Classical IP over ATM . 20 I.2 Multi-Protocol Over ATM (MPOA) 23 I.3 Multi-Protocol Label Switching (MPLS). 25 Appendix II Guidelines for mapping services to ATM connections 28 II.1 Mapping Intserv services to ATM connections
22、28 II.2 Mapping Diffserv services over ATM . 32 II.3 Intserv in MPLS over ATM . 33 II.4 Diffserv in MPLS over ATM . 33 Appendix III Possible evolution scenarios to MPLS for IP over ATM in public networks 36 III.1 Introduction 36 III.2 Proposed scenarios . 36 III.3 Hybrid ATM network. 37 Appendix IV
23、Example methods for IP-VPN support in MPLS/ATM public network. 46 IV.1 Introduction 46 IV.2 Scenario 1 . 47 IV.3 Scenario 2 . 49 BIBLIOGRAPHY 52 ITU-T Rec. Y.1310 (03/2004) 1 ITU-T Recommendation Y.1310 Transport of IP over ATM in public networks 1 Scope This Recommendation addresses the transport o
24、f IP services over ATM. IP services in this Recommendation are defined as services provided at the IP layer. IP services in this Recommendation do not include those at the application layer (e.g., network banking). This Recommendation identifies the IP over ATM approach for public networks adopting
25、ATM technology, including service provider networks and carrier networks, but does not preclude the same approach where applicable in access networks, private networks and end systems. Approaches taken into account include classical IPOA, MPOA, and MPLS. These approaches are described briefly in App
26、endix I. 2 References The following ITU-T Recommendations and other references contain provisions which, through reference in this text, constitute provisions of this Recommendation. At the time of publication, the editions indicated were valid. All Recommendations and other references are subject t
27、o revision; users of this Recommendation are therefore encouraged to investigate the possibility of applying the most recent edition of the Recommendations and other references listed below. A list of the currently valid ITU-T Recommendations is regularly published. The reference to a document withi
28、n this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. 2.1 Normative references 2.1.1 ITU-T I.321 ITU-T Recommendation I.321 (1991), B-ISDN protocol reference model and its application. I.326 ITU-T Recommendation I.326 (2003), Functional architecture of tr
29、ansport networks based on ATM. I.356 ITU-T Recommendation I.356 (2000), B-ISDN ATM layer cell transfer performance. I.361 ITU-T Recommendation I.361 (1999), B-ISDN ATM layer specification. I.364 ITU-T Recommendation I.364 (1999), Support of the broadband connectionless data bearer service by the B-I
30、SDN. I.371 ITU-T Recommendation I.371 (2004), Traffic control and congestion control in B-ISDN. I.432 ITU-T Recommendations I.432.1 (1999), I.432.2 (1999), I.432.3 (1999) and I.432.4 (1999), B-ISDN user-network interface Physical layer specification. Q.2931 ITU-T Recommendation Q.2931 (1995), Digita
31、l Subscriber Signalling System No. 2 User-Network Interface (UNI) layer 3 specification for basic call/connection control. Q.2941 ITU-T Recommendation Q.2941.2 (1999), Digital Subscriber Signalling System No. 2 Generic identifier transport extensions. Y.1311.1 ITU-T Recommendation Y.1311.1 (2001), N
32、etwork-based IP-VPN over MPLS architecture. 2 ITU-T Rec. Y.1310 (03/2004) 2.1.2 ISOC/IETF ATM_MULTI IETF RFC 2684 (1999), Multiprotocol Encapsulation over ATM Adaptation Layer 5. ATM_VCID IETF RFC 3038 (2001), VCID Notification over ATM Link for LDP. CIP_ATM IETF RFC 2225 (1998), Classical IP and AR
33、P over ATM. CONTROL_SER IETF RFC 2211 (1997), Specification of the Controlled-Load Network Element Service. CR_LDP IETF RFC 3212 (2002), Constraint-Based LSP Setup using LDP. DIFF_AF IETF RFC 2597 (1999), Assured Forwarding PHB Group. DIFF_ARCH IETF RFC 2475 (1998), An Architecture for Differentiate
34、d Services. DIFF_HEADER IETF RFC 2474 (1998), Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers. DIFF_EF IETF RFC 2598 (1999), An Expedited Forwarding PHB. GUAR_SER IETF RFC 2212 (1997), Specification of Guaranteed Quality of Service. IP_V4 IETF RFC 791 (1981),
35、Internet Protocol. IP_V6 IETF RFC 2460 (1998), Internet Protocol, Version 6 (IPv6) Specification. LDP IETF RFC 3036 (2001), LDP Specification. MPLS_ARCH IETF RFC 3031 (2001), Multiprotocol Label Switching Architecture. MPLS_ATM IETF RFC 3035 (2001), MPLS using LDP and ATM VC Switching. MPLS_DIFF IET
36、F RFC 3270 (2002), Multi-Protocol Label Switching (MPLS) Support of Differentiated Services. MPLS_ENCAPS IETF RFC 3032 (2001), MPLS Label Stack Encoding. NHRP IETF RFC 2332 (1998), NBMA Next Hop Resolution Protocol (NHRP). RSVP_AGG IETF RFC 3175 (2001), Aggregation of RSVP for IPv4 and IPv6 Reservat
37、ions. RSVP_FUN IETF RFC 2205 (1997), Resource Reservation Protocol (RSVP) Version 1 Functional Specification. RSVP_REFR IETF RFC 2961 (2001), RSVP Refresh Overhead Reduction Extensions. RSVP_TE IETF RFC 3209 (2001), RSVP-TE: Extensions to RSVP for LSP Tunnels. TCP IETF RFC 793 (1981), Transmission C
38、ontrol Protocol. UDP IETF RFC 768 (1980), User Datagram Protocol. 2.1.3 ATM Forum ATM_MPOA ATM Forum AF-MPOA-0087.000 (1997), Multi-Protocol Over ATM Specification v1.0. 2.2 Informative references 2.2.1 ISOC/IETF BGP_VPN IETF RFC 2547 (1999), BGP/MPLS VPNs. ITU-T Rec. Y.1310 (03/2004) 3 3 Terms and
39、definitions This clause lists alphabetically the acronyms of the key terms used in this Recommendation and the references to their sources of definitions. Refer to clause 4 for the acronyms and to clause 2 for the references: CR-LDP CR_LDP DS DIFF_ARCH DSCP DIFF_ARCH FEC MPLS_ARCH LIB MPLS_ARCH LSR
40、MPLS_ARCH MPLS MPLS_ARCH PHB DIFF_ARCH RSVP RSVP_FUN RSVP-TE RSVP_TE VPN BGP_VPN 4 Abbreviations and acronyms This Recommendation uses the following abbreviations: AAL ATM Adaptation Layer ABR Available Bit Rate ABT ATM Block Transfer AESA ATM End System Address ARP Address Resolution Protocol ATC A
41、TM Transfer Capability ATM Asynchronous Transfer Mode ATMARP ATM Address Resolution Protocol BGP Border Gateway Protocol BUS Broadcast and Unknown Server CE Customer Edge CE Customer Equipment C-IPOA Classical IP over ATM CLP Cell Loss Priority CLS Controlled Load Service CoF Coordination Function C
42、R-LDP Constraint-based Routing LDP DBR Deterministic Bit Rate DS Differentiated Services DSCP Differentiated Service Code Point ER Explicit Routing ES End System FEC Forwarding Equivalence Class FIB Forwarding Information Base 4 ITU-T Rec. Y.1310 (03/2004) GFR Guaranteed Frame Rate GS Guaranteed Ser
43、vice ILMI Integrated Local Management Interface IP Internet Protocol IPOA IP Over ATM IPSF IP Service Functions IP-SSCS IP-Service Specific Convergence Service IS Integrated Service ISP IP Service Provider LANE Local Area Network Emulation LDP Label Distribution Protocol LEC LANE Client LECS LANE Co
44、nfiguration Server LER Label Edge Router LES LANE Server LIB Label Information Base LIS Logical Internet Subnet LLC Logical Link Control LSP Label Switched Path LSR Label Switching Router MAC Medium Access Control MBS Maximum Burst Size MCR Minimum Cell Rate MPC MPOA Client MPLS Multi-Protocol Label
45、 Switch MPOA Multi-Protocol Over ATM MPS MPOA Server NAT Network Address Translation NHC NHRP Client NHRP Next Hop Resolution Protocol NHS NHRP Server NNI Network to Network Interface OSPF Open Shortest Path First PCI Protocol Control Information PCR Peak Cell Rate PDR Peak Data Rate PE Provider Edg
46、e PHB Per Hop Behaviour PIM Protocol Independent Multicasting PPP Point-to-Point Protocol PSC Per Hop Scheduling QoS Quality of Service RSVP Resource Reservation Protocol RSVP-TE Resource Reservation Protocol-Traffic Engineering SBR Statistical Bit Rate SLA Service Level Agreement ITU-T Rec. Y.1310
47、(03/2004) 5 SNAP Subnet Attachment Point SSCS Service Specific Control Service TCP Transmission Control Protocol TMN Telecommunications Management Network UDP User Data Protocol UNI User Network Interface VPN Virtual Private Network VPN-ID VPN Identifier xDSL x-Digital Subscriber Loop 5 Generic requ
48、irements This Recommendation places a number of generic requirements on IP over ATM approaches. Such requirements are applicable to all identified IP services. The mandatory generic requirements are as follows: The recommended approach must be independent of the IP version supported. The recommended
49、 approach must have sufficient scalability to support large networks. Items to be taken into account regarding scalability include: use of VCI and VPI values; complexity of routing calculation at Layer 2 and Layer 3; complexity of address resolution mechanism; control messaging load (e.g., frequency of setup and cleardown of ATM connections, frequency of IP-related signalling messages); complexity of the packet classification mechani
