1、 ATIS-0800058 ATIS Standard on - ANALYSIS OF CONTENT DELIVERY NETWORK USE IN THE ATIS IPTV INTEROPERABILITY FORUM AND ATIS CLOUD SERVICES FORUM As a leading technology and solutions development organization, ATIS brings together the top global ICT companies to advance the industrys most-pressing bus
2、iness priorities. 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 dev
3、elopment 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
4、 Partner 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 inf
5、ormation, visit . Notice of Disclaimer for example, when a prepared software image is made available for download to multiple recipient devices or when a system-wide message needs to be encrypted and sent to a large population of IPTV devices. ATIS-0800058 12 Figure 6: Geographically Distributed Fun
6、ctional Architecture for Linear TV (Figure 10 from 7) ATIS-0800017, Network Attachment and Initialization of Devices and Client Discovery of IPTV Services 7, specifies multicast-based service provisioning. Multicast streams are used for distribution of System Information (SI) as well as other stream
7、s such as EPG to the ITF. As per Section 10Media Delivery ServerIPTVServerMulticast stream for SIother multicast streams, e.g. EPG, etc.Join Multicast stream for SI (upon request)ITFMTFJoin other multicast streams, e.g. EPG, etc. (upon request)Service(s) DiscoveryService(s) AttachmentATIS-0800058 13
8、 Figure 7: Software Download Architecture (Figure 2 from 5) In ATIS-0800009, Remote Management of Devices in the Consumer Domain for IPTV Services, there are two cases depending on how the download control information is communicated from the network to the device: For a unicast control using TR-069
9、, the device establishes a TR-069 management session with the RCMS, which in turn provides the device with the URL of the file that contains the download information. This file is called the atis-iif-softwaredownloadlocator.xml. The content of the file is an XML document containing a single element
10、of name SoftwareDownloadLocator and XML datatypemps:ResourceLocatorType, as defined in ATIS-0800013 6. For a multicast control using an announcement mechanism, the Operator broadcasts the download information over some known channel/mechanism that contains the channel to tune to in order to get the
11、new software image. The definition of the announcement channel is out of scope for this document. The multicast download mechanism for a DNG follows the FLUTE specifications stated in ATIS-0800013 6, which in turn is based on Broadband Forum TR-069 33 and DVB RMS-FUS 34 specifications. Additional au
12、thentication and/or encryption mechanisms as defined in ATIS-0800014 15 may be used for additional security of the saved files at runtime. The trust hierarchy and certificate defined in ATIS-0800015 36 and ATIS-0800016 37 are used to support implementation of these mechanisms. ATIS-0800020 9, sectio
13、n 7.5, specifies two transport mechanisms for EPG metadata: a broadcast (“push”) mechanism in which EPG metadata files are delivered to ITF devices via IP multicast streams, and an interaction (“pull”) mechanism in which ITF devices retrieve metadata files from an HTTP server. With either the broadc
14、ast mechanism or the interaction mechanism, there are two types of EPG metadata files that need to be delivered: Service Guide Delivery Units (SGDUs). Service Guide Delivery Descriptors (SGDDs). ATIS-0800058 14 SGDUs may be delivered by the broadcast mechanism, the interaction mechanism, or both. Si
15、milarly, SGDDs may be delivered by the broadcast mechanism, the interaction mechanism, or both. The availability of EPG fragments over the broadcast and interaction channels is announced with the Transport and AlternativeAccessURL elements in the SGDDs, as specified in section 5.4.1.5.4 of the OMA B
16、CAST Service Guide specification 35. 4.1.6 Use Cases Use Cases with the identifying chapter specified in ATIS-0800042 12 relevant to the use of CDN in ATIS IIF include: 11 Internet-Sourced Content Use Cases 11.1 SERVICE PROVIDER HOSTED CONTENT ORIGIN 11.1.1 ISC Use Case 1 (SP CoD Application, SP-Hos
17、ted Content) On-Net 11.1.2 ISC Use Case 1 (SP CoD Application, SP-Hosted Content) Off-Net 11.2 CONTENT PROVIDER HOSTED CONTENT ORIGIN 11.2.1 ISC Use Case 2 (SP CoD Application, CP-Hosted Content) On-Net 11.2.2 ISC Use Case 2 (SP CoD Application, CP-Hosted Content) Off-Net 11.2.3 ISC Use Case 3 (SP a
18、nd CP Shared CoD Application, CP-Hosted Content) On-Net 11.2.4 ISC Use Case 3 (SP and CP Shared CoD Application, CP-Hosted Content) Off-Net 11.2.5 ISC Use Case 4 (CP CoD Application, CP-Hosted Content) On-Net 12 Multiscreen Use Cases 12.1.1 Service Provider-Hosted Content Origin, On-Net and Off-Net
19、12.1.2 Content Provider and Service Provider hosted Content Origin, Off-Net and On-Net 12.1.3 Content Provider hosted Content Origin, On-Net and Off-Net 12.1.4 Service Provider-Hosted Content Origin, On-Net and On-Net, IMS Inter-Provider CoD 12.1.5 Content Provider and Service Provider-Hosted Conten
20、t Origin, Off-Net and Off-Net 13 ATIS-DASH Use Cases 13.1 ATIS-DASH USE CASE A (SP-PREPARED CONTENT, ON-DEMAND) 13.2 ATIS-DASH USE CASE B (SP-MODIFIED MPD, ON-DEMAND) 13.3 ATIS-DASH USE CASE C (CP-PREPARED DASH CONTENT, ON-DEMAND) 13.4 ATIS-DASH USE CASE D (LIVE-UNICAST) The ISC use cases vary depen
21、ding on the role of the Service Provider and Content Provider in content hosting and authentication/authorization, as well as where content delivery is hosted and if the content delivery to the ITF uses On-Net or Off-Net transport. Table 1 and Table 2 summarize how the uses cases differ with respect
22、 to these factors. ATIS-0800058 15 Table 1: Internet-Sourced Content Use Cases by the Role of Service Provider/Content Provider (Table 31 from 12) Table 2: Internet-Sourced Content Use Cases by Functional Organization (Table 32 from 12) 4.2 ATIS CSF 4.2.1 Overview The ATIS Cloud Services Forum (CSF)
23、 develops interconnection use cases and high level requirements to support content distribution by service providers (referred to here as CDN Providers) over their respective networks. The use cases and supporting requirements cover the life cycle of interactions between a Primary CDN (P-CDN) Provid
24、er and a Supporting CDN (S-CDN) Provider whose network serves as the access vehicle for end users requesting the content. ATIS-0200003, CDN Interconnection Use Case Specification and High Level Requirements 14, develops interconnection use cases and high-level requirements to support content distrib
25、ution by CDN Providers. The use cases and supporting requirements cover the life cycle of interactions between a P-CDN Provider and an S-CDN Provider whose network serves as the access vehicle for end users requesting the content. This document also describes the delivery of a “simple” Off-Peak Soft
26、ware Download via the Cache Distribution Model. The objective is to derive a set of interaction requirements to gain an initial understanding of necessary routing request capabilities and provide a framework for an eventual multi-provider CDN Federation concept. Content hostSubscriberAuthenticationS
27、erviceAuthorizationAssetAuthorization(DRM/Catalogue)SessionAuthorization(E3)1 On-Net SP SP SP SP SP1 Off-Net SP SP SP SP SP2 On-Net CP SP SP SP SP2 Off-Net CP SP SP SP SP3 On-Net CP SP SP CP SP3 Off-Net CP SP SP CP SP4 On-Net CPCP(SP optional)CP CP SP(OTT*) Off-Net CP CP CP CP NAMultiscreenISC Use C
28、ase TransportRole of SP/CPCombination of ISC Use CasesSP CoD ApplicationSP/CP shared CoD ApplicationCP CoD Application SP CoD ApplicationSP/CP shared CoD ApplicationCP CoD ApplicationService Provider HostedContent Origin11.1.1Use Case 1 On-NetN/A N/A11.1.2Use Case 1 Off-NetN/A N/AContent Provider Ho
29、stedContent Origin11.2.1Use Case 2 On-Net11.2.3Use Case 3 On-Net11.2.5Use Case 4 On-Net11.2.2Use Case 2 Off-Net11.2.4Use Case 3 Off-Net(OTT*)On-Net Off-Net (through 3rd Party CDN)ATIS-0800058 16 ATIS-0200004, CDN Interconnection Use Cases and Requirements for Multicast-based Content Distribution 15,
30、 describes a means of distributing content by multicast across CDN providers, including identifying the types of content suitable for multicast, and describes various multicast deployment configurations for distribution over multiple CDN provider domains. A third CDN-related document, ATIS-0200010,
31、CDN Interconnection Use Cases and Requirements in a Multi-Party Federation Environment, was recently published by the ATIS CSF with an expanded scope including multiple CDN providers engaged in the delivery of all types of content via cache and multicast. This CSF work is beyond the scope of the cur
32、rent analysis document. 4.2.2 Architecture The ATIS CSF has not yet specified an architecture for CDN interconnection or federation, but plans to do that in future efforts. ATIS-0200003, CDN Interconnection Use Case Specification and High Level Requirements 14, provides an initial description of CDN
33、s and develops interconnection use cases and high-level requirements to support CDN interconnection between CDN Providers for delivery of a “simple” Off Peak Software Download via the Cache Distribution Model. Figure 8: Peer-Peer Interconnection between two CDNs (Figure 4 from 14) The interconnectio
34、n permits end users to receive content from the local CDN service operating in the service providers CDN, with reduced network load on both networks and reduced latency. To ensure efficient delivery, it is customary for most end users to connect directly to the S-CDN provider for their local CDN ser
35、vice. The S-CDN Providers origin server and/or nodes retrieve the content from the origin servers hosted by the P-CDN if the content is not cached and stores the content in cache, further diminishing the need for repeated requests. The initial architectural assumption for the CSF is that DNS is used
36、 for resolution of the content CDN node as shown in Figure 9. A high-level content request flow is described as follows: 1. The end user requests content from XYZ.com. 2. Local DNS retrieves the CDN Provider DNS name XYZSP.com from XYZ.com DNS. ATIS-0800058 17 3. Local DNS queries CDN Providers DNS.
37、 CDN Providers DNS responds with the IP address of the Cache Server that stores the requested Content from XYZSP.com based on rules such as: a. Load balancing. b. Geographic proximity. c. Least cost routing. 4. User retrieves content from the identified Cache Server. Figure 9: Representation of Cont
38、ent Request Flow (Figure 2 from 14) 4.2.3 Multicast Considerations ATIS-0200004, CDN Interconnection Use Cases and Requirements for Multicast-based Content Distribution 15, provides an overview of the multicast delivery mechanism, a set of content types that are suitable for delivery via multicast m
39、ethods, and a description of various multicast methods that can be deployed to interconnect CDN providers. The scope is limited to use cases and requirements to support the interaction between CDN providers for content distribution via multicast, and the specification focus is on generic interaction
40、s supporting life cycle management for multicast use between CDN providers and on specific multicast deployment configurations/scenarios for interconnection. 4.2.4 Domains The logical domains involved in distribution of the content from the CP all the way to the end user via interconnected CDN is gi
41、ven in Figure 10. The focus of ATIS-0200003, CDN Interconnection Use Case Specification and High Level Requirement 14, is on the interfaces and interaction between a P-CDN and a single S-CDN (link 3). The Content Provider owns the content and specifies the conditions of delivery and use. The end use
42、r interacts with the CP (link 1 in the figure) for authentication and authorization, and to reach an agreement ATIS-0800058 18 to obtain specific content (content selection, content purchase, acknowledgement of conditions of use). The CP has the legal right to distribute content and specify conditio
43、ns for distribution. The CP has an agreement and interacts with the P-CDN for deploying content (link 2). The P-CDN in turn has an agreement with an S-CDN for deploying content (link 3). The end user is attached to S-CDN for access and obtains the content from S-CDN (link 4). The end user also inter
44、acts with the CP (link 1) as indicated above. Figure 10: Relationships Between Main CDN Entities (Figure 3 from 14) 4.2.5 Interfaces Interfaces in the CSF are identified as high-level “links” between CDN domains as described in section 4.2.2.1. Granular interfaces have not yet been specified by the
45、CSF beyond the descriptions provided in Figure 11. This area is expected to be addressed in future work by the group in the development of the following: Reference architecture for interconnection. Initial framework of messaging capabilities required to enable the interconnection. Evaluation of prot
46、ocol capabilities to support message exchange. ATIS-0800058 19 Figure 11: Interconnection Interface Domains (Figure 7 from 14) 4.2.6 Use Cases ATIS-0200003, CDN Interconnection Use Case Specification and High Level Requirements 14, outlines a set of use cases describing the life cycle interactions b
47、etween: CPs and P-CDN providers. One P-CDN and one S-CDN provider. The specification is further limited to a relatively “simple” Off-Peak HTTP software download distribution thru the caches within the respective CDN, without authentication and authorization or SSL. Use Cases with the identifying cha
48、pter from 14 are grouped into two areas, as indicated by the below excerpt from the table of contents: 7.1 USE CASES SUPPORTING LIFE CYCLE INTERACTIONS BETWEEN THE P-CDN AND S-CDN 7.1.1 Two CDN Providers Reach CDN Interconnection Agreement 7.1.2 Primary and Supporting CDN Providers Maintain Content
49、Distribution Relationship 7.1.3 Primary and Supporting CDN Providers Terminate CDN Interconnection Agreement 7.1.4 Primary CDN Provider Conducts Post-Mortem Analysis on Supporting CDN Provider Termination Agreement 7.2 P-CDN AND CP LIFE CYCLE INTERACTIONS USE CASES INVOLVING RELEVANT P-CDN AND S-CDN INTERACTIONS 7.2.1 Primary CDN Provider Conducts Pre-Sale Testing Prior to Content Distribution 7.2.2 Primary CDN Provider Conducts Post-Sale Testing Prior to Content Distribution 7.2.3 Content Provider
