1、 I n t e r n a t i o n a l T e l e c o m m u n i c a t i o n U n i o n ITU-T Q.3711 TELECOMMUNICATION STANDARDIZATION SECTOR OF ITU (08/2016) SERIES Q: SWITCHING AND SIGNALLING Signalling requirements and protocols for SDN Resource control protocols Signalling requirements for software-defined broad
2、band access network Recommendation ITU-T Q.3711 ITU-T Q-SERIES RECOMMENDATIONS SWITCHING AND SIGNALLING SIGNALLING IN THE INTERNATIONAL MANUAL SERVICE Q.1Q.3 INTERNATIONAL AUTOMATIC AND SEMI-AUTOMATIC WORKING Q.4Q.59 FUNCTIONS AND INFORMATION FLOWS FOR SERVICES IN THE ISDN Q.60Q.99 CLAUSES APPLICABL
3、E TO ITU-T STANDARD SYSTEMS Q.100Q.119 SPECIFICATIONS OF SIGNALLING SYSTEMS No. 4, 5, 6, R1 AND R2 Q.120Q.499 DIGITAL EXCHANGES Q.500Q.599 INTERWORKING OF SIGNALLING SYSTEMS Q.600Q.699 SPECIFICATIONS OF SIGNALLING SYSTEM No. 7 Q.700Q.799 Q3 INTERFACE Q.800Q.849 DIGITAL SUBSCRIBER SIGNALLING SYSTEM N
4、o. 1 Q.850Q.999 PUBLIC LAND MOBILE NETWORK Q.1000Q.1099 INTERWORKING WITH SATELLITE MOBILE SYSTEMS Q.1100Q.1199 INTELLIGENT NETWORK Q.1200Q.1699 SIGNALLING REQUIREMENTS AND PROTOCOLS FOR IMT-2000 Q.1700Q.1799 SPECIFICATIONS OF SIGNALLING RELATED TO BEARER INDEPENDENT CALL CONTROL (BICC) Q.1900Q.1999
5、 BROADBAND ISDN Q.2000Q.2999 SIGNALLING REQUIREMENTS AND PROTOCOLS FOR THE NGN Q.3000Q.3709 SIGNALLING REQUIREMENTS AND PROTOCOLS FOR SDN Q.3710Q.3899 Resource control protocols Q.3710Q.3739 TESTING SPECIFICATIONS Q.3900Q.4099 For further details, please refer to the list of ITU-T Recommendations. R
6、ec. ITU-T Q.3711 (08/2016) i Recommendation ITU-T Q.3711 Signalling requirements for software-defined broadband access network Summary Recommendation ITU-T Q.3711 provides an overview of software-defined broadband access network (SBAN) and its procedures, and specifies the signalling requirements of
7、 the northbound interface and southbound interface of SBAN model. History Edition Recommendation Approval Study Group Unique ID* 1.0 ITU-T Q.3711 2016-08-29 11 11.1002/1000/12989 Keywords BAN, broadband access network, SDN, software-defined networking. * To access the Recommendation, type the URL ht
8、tp:/handle.itu.int/ in the address field of your web browser, followed by the Recommendations unique ID. For example, http:/handle.itu.int/11.1002/1000/11830-en. ii Rec. ITU-T Q.3711 (08/2016) FOREWORD The International Telecommunication Union (ITU) is the United Nations specialized agency in the fi
9、eld of telecommunications, information and communication technologies (ICTs). The ITU Telecommunication Standardization 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 standardi
10、zing 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 study groups which, in turn, produce Recommendations on these topics. The approval of ITU-T Recommendations is covere
11、d 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 basis with ISO and IEC. NOTE In this Recommendation, the expression “Administration“ is used for conciseness to indicat
12、e both a telecommunication administration and a recognized operating agency. Compliance with this Recommendation is voluntary. However, the Recommendation may contain certain mandatory provisions (to ensure, e.g., interoperability or applicability) and compliance with the Recommendation is achieved
13、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 of such words does not suggest that compliance with the Recommendation is required of any party. INTELLECTUAL PROP
14、ERTY RIGHTSITU 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 position concerning the evidence, validity or applicability of claimed Intellectual Property Rights, whether asserte
15、d by ITU members or others outside of the Recommendation development process. As of the date of approval of this Recommendation, ITU had not received notice of intellectual property, protected by patents, which may be required to implement this Recommendation. However, implementers are cautioned tha
16、t 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 2016 All rights reserved. No part of this publication may be reproduced, by any means whatsoever, without the prior written permission of ITU. Rec.
17、 ITU-T Q.3711 (08/2016) iii Table of Contents Page 1 Scope . 1 2 References . 1 3 Definitions 1 3.1 Terms defined elsewhere 1 3.2 Terms defined in this Recommendation . 1 4 Abbreviations and acronyms 1 5 Conventions 3 6 Introduction of SBAN . 3 7 Procedures . 4 7.1 SBAN node initialization . 4 7.2 R
18、egistration . 5 7.3 Status query 5 7.4 Service creation 5 8 The signalling requirements of SBAN . 6 8.1 Overview of signalling requirements . 6 8.2 Signalling requirements for southbound interface . 7 8.3 Signalling requirements for northbound interface 13 9 Security considerations . 18 Appendix I A
19、n example of SBAN 19 Bibliography. 21 Rec. ITU-T Q.3711 (08/2016) 1 Recommendation ITU-T Q.3711 Signalling requirements for software-defined broadband access network 1 Scope This Recommendation specifies software-defined broadband access network (SBAN) by providing: Overview of SBAN; Procedures of S
20、BAN; Signalling requirements of the northbound interface and southbound interface of SBAN model; Example of SBAN. 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
21、of publication, the editions indicated were valid. All Recommendations and other references are subject to 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 li
22、st of the currently valid ITU-T Recommendations is regularly published. The reference to a document within this Recommendation does not give it, as a stand-alone document, the status of a Recommendation. ITU-T Y.3300 Recommendation ITU-T Y.3300 (2014), Framework of software-defined networking. 3 Def
23、initions 3.1 Terms defined elsewhere This Recommendation uses the following terms defined elsewhere: 3.1.1 access network b-ITU-T Q.1742.11: Network that connects access technologies such as a radio access network to the core network. 3.1.2 software-defined networking ITU-T Y.3300: A set of techniqu
24、es that enables to directly program, orchestrate, control and manage network resources, which facilitates the design, delivery and operation of network services in a dynamic and scalable manner. 3.2 Terms defined in this Recommendation None. 4 Abbreviations and acronyms This Recommendation uses the
25、following abbreviations and acronyms: APP Application APP-ASQ SDN Application Status Query APP-ASQP SDN Application Status Query Response APP-RE SDN Application Register APP-REP SDN Application Register Response 2 Rec. ITU-T Q.3711 (08/2016) BAN Broadband Access Network BTS Base Transceiver Station
26、CE Customer Edge eNodeB Evolved Node B ID Identification IP Internet Protocol MAC Media Access Control MPLS Multi-Protocol Label Switching OAM Operation, Administration and Maintenance OPEX Operating Expense QoS Quality of Service RAN Radio Access Network RNC Radio Network Controller SBAN Software-d
27、efined Broadband Access Network SBAN-FI SBAN Flow Initiation SBAN-FIP SBAN Flow Initiation Response SBAN-FQ SBAN Flow Query SBAN-FQP SBAN Flow Query Response SBAN-NQ SBAN Network Query SBAN-NQP SBAN Network Query Response SBAN-NSI SBAN Network Service Initiation SBAN-NSIP SBAN Network Service Initia
28、tion Response SBAN-NSQ SBAN Network Service Query SBAN-NSQP SBAN Network Service Query Response SBAN-PR SBAN Node Port Register SBAN-PRP SBAN Node Port Register Response SBAN-PSQ SBAN Node Port Status Query SBAN-PSQP SBAN Node Port Status Query Response SBAN-RE SBAN Node Register SBAN-REP SBAN Node
29、Register Response SBAN-SQ SBAN Node Status Query SBAN-SQP SBAN Node Status Query Response SCTP Stream Control Transmission Protocol SDN Software-Defined Networking TCP Transmission Control Protocol TLS Transport Layer Security UDP User Datagram Protocol Rec. ITU-T Q.3711 (08/2016) 3 XML Extensible M
30、arkup Language 5 Conventions In this Recommendation: A: indicates that the parameter A is mandatory; B: indicates that the parameter B is optional; *: indicates that the parameter may be multiple items. 6 Introduction of SBAN Broadband business has become the main source of revenue for carriers, and
31、 broadband access network (BAN) plays an important role in carriers network. But there are still a number of challenges which need to be addressed in BAN, especially for IP radio access network (RAN), see Appendix I. BAN includes two types of nodes: access nodes and aggregate nodes. The access nodes
32、 connect the user devices, such as: base transceiver station (BTS), evolved node B (eNodeB), or customer edge (CE), and the aggregate nodes connect the network devices, such as radio network controller (RNC), the IP metropolitan area network nodes or the IP backbone network nodes. The network topolo
33、gy between access nodes and aggregate nodes can be ring, chain or tree structure. Taking IP RAN for example, IP RAN usually uses a ring structure for network robustness, which is depicted in Figure 6-1. Figure 6-1 Ring structure of BAN In Figure 6-1, access ports belong to access nodes that connect
34、user devices, and aggregate ports belong to aggregate nodes that connect other network nodes. Within access nodes and aggregate nodes, there are internal ports that connect to other access nodes or other aggregate nodes. There are a lot of network equipment and multiple protocols in BAN, and the net
35、work topology of BAN is complicated, so network deployment and configuration of BAN requires complex implementation and high maintenance costs. On the other hand, new value-added services and applications emerge rapidly, but it takes weeks or even months for networks to incorporate them. According t
36、o the above, SBAN aims to enable to separate the forwarding function and control function of network equipment, and to provide an open interface to applications and network managers. The functional entities of the SBAN model consist of forwarding devices, SDN controller, SDN application, southbound
37、interface and northbound interface. Considering the large number of access 4 Rec. ITU-T Q.3711 (08/2016) nodes, there is a difference between SBAN and other SDN scenarios. It is difficult for the SDN controller in SBAN to link all forwarding devices directly, especially for all access nodes. So in S
38、BAN, the SDN controller only links the aggregate nodes, and abstracts the aggregate nodes and the access nodes as a single node composed of access ports and aggregate ports, which is called an SBAN node and depicted in Figure 6-2. Figure 6-2 SBAN model SBAN significantly contributes to reducing oper
39、ating expense (OPEX) by 1) elimination of both constant maintenance and upgrades to the network equipment; 2) easy deployment of new services; and 3) improvement of the service provisioning. In SBAN, SBAN nodes perform the actions made by the SDN controller. The SDN controller provides SBAN capabili
40、ties to applications and controls SBAN nodes to meet SDN applications requirements. The southbound interface is the interface between the SBAN nodes and the SDN controller, which carry messages from the SBAN nodes to the SDN controller (e.g., the link status message) and messages from the SDN contro
41、ller to the SBAN nodes (e.g., the quality of service (QoS) policy). The northbound interface is the interface between the SDN controller and the SDN applications, which carries messages from the SDN controller to the SDN application (e.g., the network status message) and messages from the SDN applic
42、ation to the SDN controller (e.g., the network service query). 7 Procedures 7.1 SBAN node initialization First, the access nodes and the aggregate nodes are initialized without the SDN controller. The access nodes send their information to the aggregate nodes through the internal interface, such as:
43、 manufacturer identification, equipment models, media access control (MAC) address, access ports, internal ports. The aggregate nodes collect the information from the access nodes or the other aggregate nodes in the same network. Then the aggregate nodes negotiate with each other to elect the master
44、 aggregate node and the slave aggregate nodes. The master aggregate node communicates on behalf of the SBAN node with the SDN controller, as depicted in Figure 7-1. Rec. ITU-T Q.3711 (08/2016) 5 Figure 7-1 SBAN node initialization The master aggregate node has all the information about the access po
45、rts and the aggregate ports, and synchronizes with the slave aggregate nodes. When the master aggregate node fails, one of the slave aggregate nodes will become the new master aggregate node which represents the SBAN nodes to maintain communication with the SDN controller. The internal interface bet
46、ween the aggregate nodes and the access nodes is not included in this Recommendation. 7.2 Registration After the SBAN node finishes its initialization, the master aggregate node is registered in the SDN controller as the representation of the SBAN node. In this process, the master aggregate node ann
47、ounces its information to the SDN controller, such as: address information, the slave aggregate nodes information. The SDN controller responds with the registration information, and allocates an SBAN node identification (ID) to the master aggregate node. The master aggregate node registers all the p
48、orts, including the access ports and the aggregate ports of the SBAN node, by using the SBAN node ID in the SDN controller. Meanwhile, the SDN application is registered in the SDN controller. 7.3 Status query After the SBAN node and the SDN application are registered in the SDN controller, the SDN c
49、ontroller queries the their status. And the SDN application queries the topology and abilities of the SBAN nodes through the SDN controller. 7.4 Service creation The SDN application initiates the network service of the SBAN nodes, and the SDN controller receives and translates the initiation. Then the SDN controller initiates the flows in the SBAN nodes. 6 Rec. ITU-T Q.3711 (08/2016) 8 The signalling requirements of SBAN 8.1 Overview of signalling requirements For controlling the SBAN network, the messages over the southb
