1、 International Telecommunication Union ITU-T G.8080/Y.1304TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU Amendment 1(03/2008) SERIES G: TRANSMISSION SYSTEMS AND MEDIA, DIGITAL SYSTEMS AND NETWORKS Packet over Transport aspects Ethernet over Transport aspects SERIES Y: GLOBAL INFORMATION INFRASTRUCT
2、URE, INTERNET PROTOCOL ASPECTS AND NEXT-GENERATION NETWORKS Internet protocol aspects Transport Architecture for the automatically switched optical network (ASON) Amendment 1 Recommendation ITU-T G.8080/Y.1304 (2006) Amendment 1 ITU-T G-SERIES RECOMMENDATIONS TRANSMISSION SYSTEMS AND MEDIA, DIGITAL
3、SYSTEMS AND NETWORKS INTERNATIONAL TELEPHONE CONNECTIONS AND CIRCUITS G.100G.199 GENERAL CHARACTERISTICS COMMON TO ALL ANALOGUE CARRIER-TRANSMISSION SYSTEMS G.200G.299 INDIVIDUAL CHARACTERISTICS OF INTERNATIONAL CARRIER TELEPHONE SYSTEMS ON METALLIC LINES G.300G.399 GENERAL CHARACTERISTICS OF INTERN
4、ATIONAL CARRIER TELEPHONE SYSTEMS ON RADIO-RELAY OR SATELLITE LINKS AND INTERCONNECTION WITH METALLIC LINES G.400G.449 COORDINATION OF RADIOTELEPHONY AND LINE TELEPHONY G.450G.499 TRANSMISSION MEDIA AND OPTICAL SYSTEMS CHARACTERISTICS G.600G.699 DIGITAL TERMINAL EQUIPMENTS G.700G.799 DIGITAL NETWORK
5、S G.800G.899 DIGITAL SECTIONS AND DIGITAL LINE SYSTEM G.900G.999 QUALITY OF SERVICE AND PERFORMANCE GENERIC AND USER-RELATED ASPECTS G.1000G.1999 TRANSMISSION MEDIA CHARACTERISTICS G.6000G.6999 DATA OVER TRANSPORT GENERIC ASPECTS G.7000G.7999 PACKET OVER TRANSPORT ASPECTS G.8000G.8999Ethernet over T
6、ransport aspects G.8000G.8099 MPLS over Transport aspects G.8100G.8199 Quality and availability targets G.8200G.8299 Service Management G.8600G.8699 ACCESS NETWORKS G.9000G.9999 For further details, please refer to the list of ITU-T Recommendations. Rec. ITU-T G.8080/Y.1304 (2006)/Amd.1 (03/2008) i
7、Recommendation ITU-T G.8080/Y.1304 Architecture for the automatically switched optical network (ASON) Amendment 1 Summary Amendment 1 to Recommendation ITU-T G.8080/Y.1304 contains: G.8080/Y.1304 Corrigendum 1 (09/2007) G.8080/Y.1304 Erratum 1 (04/2007) Additions to allow ASON to apply to packet tra
8、nsport networks Updates to TAP and LRM, including clarification of SNP binding states. Source Amendment 1 to Recommendation ITU-T G.8080/Y.1304 (2006) was approved on 29 March 2008 by ITU-T Study Group 15 (2005-2008) under Recommendation ITU-T A.8 procedure. ii Rec. ITU-T G.8080/Y.1304 (2006)/Amd.1
9、(03/2008) 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 Standardization Sector (ITU-T) is a permanent organ of ITU. ITU-T is responsibl
10、e 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, establishes the topics for study by the ITU-T
11、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 standards are prepared on a collaborative ba
12、sis 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 Recommendation may contain certain mandator
13、y 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 used to express requirements. The use
14、 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 Intellectual Property Right. ITU takes no
15、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 received notice of intellectual property, prote
16、cted 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 database at http:/www.itu.int/ITU-T/ipr/. ITU 2009 All rights reserved. No part o
17、f this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec. ITU-T G.8080/Y.1304 (2006)/Amd.1 (03/2008) 1 Recommendation ITU-T G.8080/Y.1304 Architecture for the automatically switched optical network (ASON) Amendment 1 Summary Replace the existing
18、 summary with the following: This Recommendation describes the reference architecture for the control plane of the Automatically Switched Optical Network as applicable to connection-oriented circuit or packet transport networks, as defined in Recommendation ITU-T G.805. This reference architecture i
19、s described in terms of the key functional components and the interactions between them. 1 Scope Replace the first paragraph with the following: This Recommendation specifies the architecture and requirements for the automatic switched transport network as applicable to connection-oriented circuit o
20、r packet transport networks, as defined in ITU-T G.805. 2 References Add the following references: ITU-T G.800 Recommendation ITU-T G.800 (2007), Unified functional architecture of transport networks. ITU-T G.7718 Recommendation ITU-T G.7718/Y.1709 (2005), Framework for ASON management. 3 Definition
21、s Add the following definition: FwPt: See ITU-T G.800. Add the following definitions after definition 3.53: 3.54 potential (resource) label range: The potential (resource) label range is the range of resource labels in the transport plane name space that an adaptation function supports to distinguis
22、h different information flows. 3.55 configured (resource) label: A “configured (resource) label“ is a label that has been configured in the transport plane in support of a connection. For each configured label, a forwarding table entry exists on the receiving end of the link such that packets can be
23、 forwarded based on the label value of the received packet. 3.56 allocated (resource) label range: The “allocated label range“ is the set of labels that can be used by the adaptation function of a particular link to carry user traffic. It is a subset of the potential resource label range. The alloca
24、ted labels are entities that can be referenced in the transport plane name space. Each allocated label is associated with one or multiple SNP IDs that exist in the control plane name space (1:n relationship). TAP holds this binding information. 2 Rec. ITU-T G.8080/Y.1304 (2006)/Amd.1 (03/2008) 3.57
25、potential SNPs: Potential SNPs are those SNPs that are associated with a (resource) label. In general, multiple SNPs can be associated with a single label. The different SNPs associated with the same (resource) label typically belong to different SNPPs. 3.58 assigned SNPs: Assigned SNPs are those SN
26、Ps out of the set of potential SNPs that have been assigned to a particular connection. This means that the associated label corresponds to a configured label. 6.1 Transport entities Replace the sentence: A number of transport systems support variable adaptation, whereby a single server layer trail
27、may dynamically support different multiplexing structures. With the following: A number of transport systems support variable adaptation, whereby a single server layer trail may dynamically support different clients. For example, different GFP mappings for packet clients or different multiplexing st
28、ructures for SDH/OTN. The description below illustrates the application to the latter. Add the following to the end of the clause In the case of circuit switching, the SNP is bound to a resource label, which provides a resource reservation and allocation. In the case of packet switching, the SNP is
29、not directly bound to a resource label, and the resource label does not carry either any resource allocation. Therefore, in the case of packet switching, when a connection is established, an SNP is selected from a range of SNPs that is bound to a resource label. The connection request should include
30、 a resource reservation (CIR and EIR). 6.3 Topology and discovery Replace this clause as follows: The routing function understands topology in terms of SNPP links. Before SNPP links can be created, the underlying transport topology, i.e., the trail relationship between the access points, must be est
31、ablished. These relationships may be discovered (or confirmed against a network plan) using a number of different techniques; for example, use of a test signal or derived from a trail trace in the server layer. They may also be provided by a management system based on a network plan. The capability
32、of the transport equipment to support flexible adaptation functions (and thus link connections for multiple client layer networks) may also be discovered or reported. Link connections that are equivalent for routing purposes are then grouped into links. This grouping is based on parameters, such as
33、link cost, delay, quality or diversity. Some of these parameters may be derived from the server layer but in general they will be provisioned by the management plane. Separate links may be created (i.e., link connections that are equivalent for routing purposes may be placed in different links) to a
34、llow the division of resources between different ASON networks (e.g., different VPNs) or between resources controlled by ASON and the management plane. The link information (e.g., the constituent link connections or resource label range with the available link bandwidth) is then used to configure th
35、e LRM instances (as described in clause 7.3.3) associated with the SNPP link. Additional characteristics of the link, based on parameters of the (potential) link connections, may also be provided. The LRMs at each end of the link must establish a control plane adjacency that corresponds to the SNPP
36、link. The interface SNPP ids may be negotiated during adjacency discovery or may be provided as part of the LRM configuration. The link connections and CP names or resource labels (and link connections) are then mapped to interface SNP ids (and SNP Link Connection names). In the case where both ends
37、 of the link are Rec. ITU-T G.8080/Y.1304 (2006)/Amd.1 (03/2008) 3 within the same routing area the local and interface SNPP id and the local and interface SNP ids may be identical. Otherwise, at each end of the link the interface SNPP id is mapped to a local SNPP id and the interface SNP ids are ma
38、pped to local SNP ids. This is shown in Figure 11. Figure 11 Relationship between local and interface ids The resulting SNP link connections may then be validated by a discovery process. The degree of validation required at this stage is dependent on integrity of the Link Connection relationships in
39、itially provided by the transport plane or management plane and the integrity of the process used to map CPs to SNPs. Validation may be derived from a trail trace in the server layer or by using a test signal and test connections. If test connections are used, the discovery process may set up and re
40、lease these connections using either the management plane or the control plane. If the control plane is used, the Link must be made temporarily available to routing and connection control, for test connections only. Once the SNPP link validation is completed, the LRMs inform the RC component (see cl
41、ause 7.3.2) of the SNPP Link adjacency and the link characteristics, e.g., cost, performance, quality, diversity, and bandwidth. 7 Control plane architecture Replace the following bullet: Support various transport infrastructures, such as the SONET/SDH transport network, as defined in ITU-T Rec. G.8
42、03, and the Optical Transport Network (OTN), as defined in ITU-T Rec. G.872. With the following: Support various transport infrastructures, such as those covered by ITU-T G.805. 4 Rec. ITU-T G.8080/Y.1304 (2006)/Amd.1 (03/2008) 7.3.1 Connection controller (CC) component Replace Table 2 with the foll
43、owing updated table: Table 2 Connection controller component interfaces Input interface Basic input parameters Basic return parameters Connection Request In A pair of local SNP names and optionally a route A subnetwork connection Peer coordination In 1) A pair of SNP names; or 2) SNP and SNPP; or 3)
44、 SNPP pair; or 4) route Confirmation signal Output interface Basic output parameters Basic return parameters Route Query Unresolved route fragment Route Link Connection Request A Link Connection (an SNP pair) Connection Request Out A pair of local SNP names A subnetwork connection Peer coordination
45、Out 1) A pair of SNP names; or 2) SNP and SNPP; or 3) SNPP pair; or 4) route Confirmation signal Remote topology status Out Topology information (link and/or subnetwork) including resource availability Figure 22 Connection controller component 7.3.3 Link resource manager (LRMA and LRMZ) component Re
46、place this clause as follows: The LRM components are responsible for the management of an SNPP link; including the assignment and unassignment of SNP link connections (to a connection), managing resource reservation, configuration of policing and shaping functions (if required), providing topology a
47、nd status information. LRM functions for circuit and packet switching are shown in Figure 23.1. Since an SNPP link can be either public or private, an LRM can also be either public or associated to exactly one VPN. Rec. ITU-T G.8080/Y.1304 (2006)/Amd.1 (03/2008) 5 Layer network using circuit switchi
48、ng The TAP supplies FwPt1and the corresponding resource labels to the LRM and associates these resource labels to SNP identifiers. When the TAP allocates a SNP identifier, the transport plane link connection is created; this provides an implicit reservation of the link resource. Tracking the assigne
49、d SNP identifiers allows the LRM to track link utilization. Since traffic loading is inherently constrained, policing and shaping functions are not required. In general, the same SNP identifier and resource label are used for both directions of a bidirectional connection. Layer network using packet switching The TAP supplies capacity and resources label to the LRM and associates these resource labels to SNP identifiers. The transport plane FwP and link connections are not created until a SNP identifier is assigned by the LRM. When
