1、 International Telecommunication Union ITU-T Y.2613TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (03/2010) SERIES Y: GLOBAL INFORMATION INFRASTRUCTURE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Next Generation Networks Future networks General technical architecture for public packet t
2、elecommunication data network Recommendation ITU-T Y.2613 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.3
3、00Y.399 Interfaces and protocols Y.400Y.499 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
4、 capabilities and resource management Y.1200Y.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 IPTV over NGN Y.1900Y.1999 NEXT GENERATION
5、NETWORKS Frameworks and functional architecture models Y.2000Y.2099 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 address
6、ing Y.2300Y.2399 Network management Y.2400Y.2499 Network control architectures and protocols Y.2500Y.2599 Future networks Y.2600Y.2699Security Y.2700Y.2799 Generalized mobility Y.2800Y.2899 Carrier grade open environment Y.2900Y.2999 For further details, please refer to the list of ITU-T Recommendat
7、ions. Rec. ITU-T Y.2613 (03/2010) i Recommendation ITU-T Y.2613 General technical architecture for public packet telecommunication data network Summary Recommendation ITU-T Y.2613 specifies the technical architecture of a public packet telecommunication data network (PTDN) which can meet all the req
8、uirements described in Recommendation ITU-T Y.2601, including the format of the data link frame and network packet, as well as the OAM and interworking methods with other packet bearer networks. History Edition Recommendation Approval Study Group 1.0 ITU-T Y.2613 2010-03-16 13 Keywords FPBN, interwo
9、rking, link layer, network layer, OAM, PTDN, routing. ii Rec. ITU-T Y.2613 (03/2010) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the field of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Stan
10、dardization Sector (ITU-T) is a permanent 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), w
11、hich meets every four years, establishes 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
12、 ITU-Ts purview, the necessary standards 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 Recommenda
13、tion is voluntary. However, the Recommendation 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 “m
14、ust“ and the negative equivalents are 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
15、may involve the use of a claimed Intellectual 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 t
16、his Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned that this may not represent the latest information and are therefore strongly urged to consult the TSB patent da
17、tabase at http:/www.itu.int/ITU-T/ipr/. ITU 2010 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T Y.2613 (03/2010) iii CONTENTS Page 1 Scope 1 2 References. 1 3 Definitions and terms 1 3.1 Terms defin
18、ed elsewhere 1 3.2 Terms defined in this Recommendation 2 4 Abbreviations 2 5 Reference model . 3 5.1 Connection-oriented mode . 4 5.2 Connectionless mode 5 6 Link layer 5 6.1 Data framing . 5 6.2 Point-to-point multiplex . 6 6.3 Frame format and field definitions . 6 6.4 Control and management 11 7
19、 Network layer . 12 7.1 Network address . 12 7.2 Packet format and field definitions . 12 7.3 Control and management 17 8 Access and interworking 17 8.1 Interworking . 17 8.2 General functions 18 8.3 Components 19 9 OAM . 19 9.1 Connectionless mode 19 9.2 Connection-oriented mode . 20 Bibliography.
20、22 Rec. ITU-T Y.2613 (03/2010) 1 Recommendation ITU-T Y.2613 General technical architecture for public packet telecommunication data network 1 Scope Public packet telecommunication data network (PTDN) is a packet data network designed for the NGN transport stratum, which should be secure, trustworth
21、y, controllable, and manageable. It can meet all the requirements described in ITU-T Y.2601. This Recommendation defines the technical architecture of PTDN, including the format of the data link frame and network packet, as well as the OAM and interworking methods with other packet bearer networks.
22、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 to revisio
23、n; 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 within this Re
24、commendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T I.432 Recommendation ITU-T I.432 (1993), B-ISDN user-network interface Physical layer specification. ITU-T Q.921 Recommendation ITU-T Q.921 (1997), ISDN user-network interface Data link layer specificatio
25、n. ITU-T Y.2601 Recommendation ITU-T Y.2601 (2006), Fundamental characteristics and requirements of future packet based networks. IEEE 802.3 IEEE 802.3 (in force), Information technology Telecommunications and information exchange between systems local and metropolitan area networks Specific require
26、ments Part 3: Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access method and Physical Layer Specifications. 3 Definitions and terms 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 address ITU-T Y.2601: An address is the identifier
27、 for a specific termination point and is used for routing to this termination point. 3.1.2 control plane b-ITU-T Y.2011: The set of functions that controls the operation of entities in stratum or layer under consideration, plus the functions required to support this control. 3.1.3 data plane b-ITU-T
28、 Y.2011: The set of functions used to transfer data in the stratum or layer under consideration. 3.1.4 identifier ITU-T Y.2601: An identifier is a series of digits, characters and symbols or any other form of data used to identify subscriber(s), user(s), network element(s), function(s), network enti
29、ty(ies) providing services/applications, or other entities (e.g., physical or logical objects). 2 Rec. ITU-T Y.2613 (03/2010) NOTE Identifiers can be used for registration or authorization. They can be either public to all networks, shared between a limited number of networks or private to a specifi
30、c network (private identifiers are normally not disclosed to third parties). 3.1.5 management plane b-ITU-T Y.2011: The set of functions used to manage entities in the stratum or layer under consideration, plus the functions required to support this management. 3.1.6 name b-ITU-T Y.2611: A name is t
31、he identifier of an entity (e.g., subscriber, network element) that may be resolved/translated into an address. 3.1.7 user plane ITU-T Y.2601: A classification for objects whose principal function is to provide transfer of end-user information: user information may be user-to-user content, or privat
32、e user-to-user data. 3.2 Terms defined in this Recommendation This Recommendation defines the following term: 3.2.1 public packet telecommunication data network (PTDN): A packet data network designed for the NGN transport stratum, which should be secure, trustworthy, controllable, and manageable, ca
33、n meet all the requirements described in ITU-T Y.2601. PTDN is a hierarchical network, which can be subdivided into several network layers. 4 Abbreviations This Recommendation uses the following abbreviations: BECN Backward Explicit Congestion Notification DLCI Data Link Connection Identifier FDI Fo
34、rward Defect Indication FECN Forward Explicit Congestion Notification GFP Generic Framing Procedure HDLC High-level Data Link Control IP Internet Protocol IWF InterWorking Function LCN Logical Channel Number LC-ID Logical Channel ID OAM Operation, Administration and Maintenance PDN Public packet Dat
35、a Network PTDN Public packet Telecommunication Data Network QoS Quality of Service TE Terminal Equipment URL Uniform Resource Locator VC Virtual Circuit/Virtual Connection Rec. ITU-T Y.2613 (03/2010) 3 5 Reference model The reference model of PTDN is shown in Figure 5-1. MEMSRSRSRSRSRSRSRSRSRSRRRRRO
36、thernetworksOthernetworksEDADTEDEEEERRT TCore networkAggregationnetworkAccessnetworkEnd systemsor othernetworksPTDNEnd systemEnd systemY.2613(2010)_F5-1Figure 5-1 Reference model of PTDN PTDN is a hierarchical network, which consists of access network, aggregation network, and core network. Moreover
37、, access network, aggregation network and core network are hierarchical networks too, which can be subdivided into several network layers. SRs (PTDN nodes) connect each other by Interface R. MEs (management elements) connect to the SRs by Interface M. EDs (edge devices) are located on the boundary o
38、f PTDN. Through Interface E, an ED can serve as an adapter between the end systems or other networks (e.g., IP network, ATM network) and PTDN network. Thus above the EDs, there are the trustable network domains. EDs can also support the mobility of end systems or other networks. 4 Rec. ITU-T Y.2613
39、(03/2010) ADTs (address translators) are responsible for the mapping or translation of IP addresses (or other network addresses) to PTDN addresses. ADTs cooperate with EDs to achieve the activities of address mapping/translation by Interface T. PTDN supports connection-oriented mode and connectionle
40、ss mode. 5.1 Connection-oriented mode 5.1.1 Control flow in connection-oriented mode In connection-oriented mode, the control flow can set up or tear down the virtual circuit for the data plane, as shown in Figure 5-2. Where: control flow Figure 5-2 Control flow transportation in connection-oriented
41、 mode 5.1.2 Data flow in connection-oriented mode In connection-oriented mode, the data flows are forwarded in a logic channel in the link layer, as shown in Figure 5-3. Where: data flow Figure 5-3 Data flow transportation in connection-oriented mode Rec. ITU-T Y.2613 (03/2010) 5 5.2 Connectionless
42、mode 5.2.1 Control flows in connectionless mode In connectionless mode, the control flows are forwarded per-hop in the control plane of the network layer according to the source address and destination address, as shown in Figure 5-4. Where: control flow Figure 5-4 Control flow transportation in con
43、nectionless mode 5.2.2 Data flow in connectionless mode In connectionless mode, data flows are forwarded per-hop in the data plane of the network layer according to the source address and destination address, as shown in Figure 5-5. Where: data flow Figure 5-5 Data flow transportation in connectionl
44、ess mode 6 Link layer The link layer is used to provide point-to-point multiplexing and/or packet encapsulation. In connection-oriented mode, data packets are encapsulated and multiplexed based on LC-ID. In connectionless mode, link layer only implements data packets encapsulation. 6.1 Data framing
45、The packets are encapsulated into a frame before forwarding. There are three methods of encapsulation: 1) The flag sequence delimiter encapsulation: HDLC adopts this technology, the flag is 01111110. The data packet and upper control signalling will be carried between two flags. 2) Header error cont
46、rol, length delimiter encapsulation: GFP and ATM adopt this technology. Usage of this technology is described in clause 4.3 of ITU-T I.432. 3) Preamble and start frame delimiter encapsulation: The packets of Ethernet network will be encapsulated by this technology. Usage of this technology is descri
47、bed in IEEE 802.3. 6 Rec. ITU-T Y.2613 (03/2010) Any kind of the encapsulation methods can be adopted in PTDN. 6.2 Point-to-point multiplex The link layer uses the logical channel for each pair to support point-to-point multiplexing. The logical channel should be identified by the logical channel nu
48、mber, i.e., logical channel ID (LC-ID). LC-ID is locally valid and used in the connection-oriented mode. 6.3 Frame format and field definitions To help understand the structure of the link layer frame format, the flag sequence delimiter encapsulation is used as an example here. According to this met
49、hod of encapsulation, the link layer frame of PTDN contains four parts: flag sequence, frame header, information section, and cyclic redundancy check (CRC). The link layer frame format is shown in Figure 6-1. Figure 6-1 Link layer frame format 6.3.1 Flag sequence All frames start and end with the flag sequence consisting of one 0 bit followed by six contiguous 1 bits and one 0 bit. The flag preceding the frame header is defined as the opening flag. The flag
