CDNI Working Group Wei Ni Internet Draft Yana Bi Intended status: Standards Track Yunfei Zhang Expires: January 2013 China Mobile July 9, 2012 CDNI Delivery Criteria Metadata Extension for Mobile Network draft-ni-cdni-criteria-metadata-extension-00.txt Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." 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He et all Expires January 9, 2013 [Page 1] Internet-Draft Criteria Metadata Extension July 2012 Abstract In CDNI deployment, the downstream CDN may probably delivers content to mobile devices, which is served by cellular networks (e.g., 2G, 3G). The purpose of this document is to provide some complement to the delivery criteria in current Metadata Interface with a more precise criteria model, which is in consideration of content delivery service to mobile devices. Table of Contents 1. Introduction ................................................ 3 1.1. Terminology ............................................ 3 1.2. Abbreviations .......................................... 3 2. Conventions used in this document ........................... 3 3. Internet Gateway in Mobile Network .......................... 4 4. CDNI with Mobile Access Scenario ............................ 5 5. Delivery Criteria in Metadata Interface ..................... 8 6. Security Considerations ..................................... 9 7. IANA Considerations ......................................... 9 8. References ................................................. 10 8.1. Normative References .................................. 10 8.2. Informative References ................................ 10 9. Acknowledgments ............................................ 11 Ni et all Expires January 9, 2013 [Page 2] Internet-Draft Criteria Metadata Extension July 2012 1. Introduction In some CDNI deployment, the downstream CDN may probably deliver content to mobile devices, which serves by 2G/3G cellular networks. In some cases, the User Agent is connected to CDN's surrogate via an intermediate gateway (eg., WAP Gateway and Internet Gateway). The metadata interface is defined by several CDNI documents, such as [draft-caulfield-cdni-metadata-core-00], [draft-liu-cdni-metadata- interface-01], and [draft-jenkins-cdni-metadata-00]. For the reason of copyright protection, CSPs often need to restrict content access to users in certain regions (e.g., within a given country or through a given access network). The delivery criteria metadata provides a list of valid source IP subnets from which content requests may be accepted. However, few considerations have been made for mobile network. This document focuses on the delivery criteria in the metadata interface. It enables a downstream CDN to obtain more information about cellular network, so that the downstream CDN can properly process and respond to content request from mobile devices. 1.1. Terminology This document reuses the terminology defined in [I-D.draft-cdni- problem-statement] and [draft-fmn-cdni-advanced-use-cases-00]. 1.2. Abbreviations o UE: User Equipment o MSISDN: Mobile Subscriber ISDN Number o APN: Access Point Name o WAP: Wireless Application Protocol o HLR: Home Location Register 2. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC-2119 [RFC2119]. Ni et all Expires January 9, 2013 [Page 3] Internet-Draft Criteria Metadata Extension July 2012 3. Internet Gateway in Mobile Network In cellular network, some mobile devices are not powerful enough to render and process web pages built for desktop browsers. So WAP Gateway (or Internet Gateway) is extensively deployed as a bridge to ensure the connection and conversion of information between mobile devices and content server. For example, WAP Gateway unpacks all the layers in the stack, translates requests from a wireless protocol to Internet protocols, and compresses the original content into a compact format in order to save bandwidth over the air and reduce the processing requirements for mobile device. With the advent of fast processors, large memory and the deployment of 3G and 4G networks, many mobile devices can directly process web pages and content without WAP Gateway. However, APN identifies the form of access, in most cases one APN setting (i.e. "cmwap" for China Mobile, and "uniwap" for China Unicom) is used for both Internet and WAP access. Users may access different information sources with a single APN. In this condition, all the requests from the mobile devices will be sent to the WAP Gateway. Figure 1 shows a typical end-to-end WAP system in mobile networks. WAP Gateway locates between the mobile network service provider's core network and the content server. +------------+ +---------------+ | WAP Gateway|---------| Content Server| +------------+ +---------------+ | | ,--,--,--. ,--,--,--. ,-' `-. ,-' `-. ( Core Network )---------( Mobile Access ) `-. ,-' `-. Network ,-' `--'--'--' `--'--'--' | | +------------+ | Mobile UE | +------------+ Ni et all Expires January 9, 2013 [Page 4] Internet-Draft Criteria Metadata Extension July 2012 Figure 1 Typical architecture of WAP system in mobile network In addition to the protocol translation and content compression, WAP Gateway can be configured to provide additional information through HTTP headers, for instance the IP address of UE, user's MSISDN, type of mobile network, and even cell ID. The following is an example of HTTP request sent from WAP Gateway to content server. The x-forwarded-for header field specifies the UE's IP address assigned by the mobile core network. The x-up-calling- line-id header field specifies user's MSISDN. GET /articles/news/default.aspx HTTP/1.1 Accept: */* Accept-Language: en-us Connection: Keep-Alive Host: wap.monternet.com Referer: http:// wap.monternet.com/default.jsp Accept-Encoding: gzip, deflate x-CTRL-Req: x_Ctrl_Version =v1.0 User-Agent = Nokia5100/2.0 Profile/MIDP-1.0 Configuration/CLDC- 1.0 x-wap-profile = "http://nds1.nds.nokia.com/uaprof/N6220r100.xml" x-bear-type=GPRS x-forwarded-for=10.18.18.1 x-up-calling-line-id =8613912345678 x-source-id=192.111.111.1 4. CDNI with Mobile Access Scenario In many cases, CDN may deliver content to mobile devices as well as PC. In CDNI deployment, mobile devices can also access the content of CSP via mobile networks and dCDN/uCDN, as depicted in Figure 2. Ni et all Expires January 9, 2013 [Page 5] Internet-Draft Criteria Metadata Extension July 2012 +------+ +------+ +------+ | dCDN |------| uCDN |------| CSP | +------+ +------+ +------+ | | +----------------+ | WAP Gateway | +----------------+ / \ / \ ,--,--,--. ,--,--,--. ,-' `-. ,-' `-. ( Mobile Network )-------( Mobile Network ) `-. ,-' `-. ,-' `--'--'--' `--'--'--' | | | | +------------+ +------------+ | Mobile UE | | Mobile UE | +------------+ +------------+ Figure 2 Content access via mobile networks in CDNI deployment Scenario 1: During packet switch attachment, mobile device is assigned an IP address by the entities of core network (i.e. GGSN or PDSN). For different configurations of APN, the IP address could be either public or private. As mentioned before, WAP Gateway is the aggregation point of all requests from mobile devices. It provides a Network Address Translator function that maps the mobile device's IP address and port number combination to a public IP address and port number. In this condition, the downstream CDN receives content request from the WAP Gateway's IP address. The IP address of mobile devices assigned by mobile core network cannot be seen by dCDN. Typically, the amount of WAP gateway is much less than that of the Core Network entities (i.e. GGSN and PDSN). In real deployments, several GGSN/PDSN is connected to one WAP Gateway. Ni et all Expires January 9, 2013 [Page 6] Internet-Draft Criteria Metadata Extension July 2012 CSPs often need to restrict content access to users in certain regions (e.g., within a given country or through a given access network). In some cases, CSP may need to apply geo-blocking policy with finer granularity (e.g., in province level or city level). So common geo-blocking information (i.e., AS number and IP subnet) cannot provide such kind of location information very well. Scenario 2: MSISDN is the most important numbers used for identifying a mobile subscriber. For data services and applications provided by network operator, MSISDN is usually used as user's default account, so the users do not need to input username and password manually. MSISDN consists of following parts: O CC Country code. O NDC National destination code. O SN Subscriber number(e.g., H0 H1 H2 H3 A B C D) The first few digits of SN specify HLR Identifier, which is also used to provide user's area information. An assignment example in China Mobile is shown in Table 1. +-------------+---------------+---------------+ | Case No. | Area Code | Location/City | | | | | +-------------+---------------+---------------+ | 1 | 0101 | Beijing | +-------------+---------------+---------------+ | 2 | 0201 | Tianjin | +-------------+---------------+---------------+ | 3 | 0301 | Shenzhen | +-------------+---------------+---------------+ | 4 | 0401 | Shenyang | +-------------+---------------+---------------+ | 5 | 0501 | Zhangzhou | +-------------+---------------+---------------+ | 6 | 0601 | Xiamen | +-------------+---------------+---------------+ | 7 | 0801 | Chengdu | +-------------+---------------+---------------+ | 8 | 0901 | Guangzhou | +-------------+---------------+---------------+ Table 1. Area code assignment example Ni et all Expires January 9, 2013 [Page 7] Internet-Draft Criteria Metadata Extension July 2012 In some cases, CSPs need t apply blocking policy using MSISDN information. In this condition, MSISDN should be taken into consideration for precise control policy. Even roaming to other area, a mobile user can still have right to access the content. 5. Delivery Criteria Extension The CDNI Metadata interface allows signaling of content distribution control policies, such as geo-blocking information, availability windows, and delegation whitelist/blacklist. To achieve more precise control of blocking policy for mobile network, more information should be able to convey via in-band mechanisms, and be considered by the downstream CDN when delivering content to users. The Delivery Criteria object specifies a set of criteria to match against incoming content requests including protocol, region and time window. The Region object specifies a region where the content is either allowed or disallowed. A region may be described in several ways, only one of which needs to be present per Region object. The object includes the following fields: O country - a string containing the country code for the region. O bgpAs - a number containing the BGP AS identifier of the region. O subnet - a string containing a dotted decimal IP address and subnet mask, here the IP address is the source IP address in IP layer. O msdnPrefix - a few digits in MSISDN specifying user's home area information in mobile network. MSISDN should be extracted from HTTP Header by the surrogate of downstream CDN. O subnet2 - a string containing a dotted decimal IP address extracted from the HTTP x-forwarded-for header and the corresponding subnet mask, which specifies the real IP address of mobile devices assigned by mobile core network. The IP address should be extracted from HTTP Header by the surrogate of downstream CDN. If the Region object is set and the IP address or MSISDN of a requesting client does not match any of the metadata listed, the downstream CDN should respond to the content request with a 403 Forbidden status code. Ni et all Expires January 9, 2013 [Page 8] Internet-Draft Criteria Metadata Extension July 2012 Example Object 1: "deliveryCriteria" : [ { "region" : { "subnet" : "10.1.0.54/18" }, }, { "protocol" : "http" } ] Example Object2: "deliveryCriteria" : [ { "region" : { "subnet2" : "10.5.31.10/24" }, }, { "protocol" : "http" } ] Example Object3: "deliveryCriteria" : [ { "region" : { "msdnPrefix" : "135038" }, } { "protocol" : "http" } ] 6. Security Considerations TBD. 7. IANA Considerations This document makes no request of IANA. Ni et all Expires January 9, 2013 [Page 9] Internet-Draft Criteria Metadata Extension July 2012 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. [RFC3986] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource Identifiers (URI): Generic Syntax and Semantics", RFC 3986, January 2005. 8.2. Informative References [I-D.draft-cdni-problem-statement] "Content Distribution Network Interconnection (CDNI) Problem Statement", B. Niven-Jenkins, F. Le Faucheur, N. Bitar, June, 2012. [I-D.draft-cdni-requirements] "Content Distribution Network Interconnection (CDNI) Requirements", K. Leung, Y. Lee, September, 2011. [I-D.davie-cdni-framework] B. Davie, and L. Peterson, "Framework for CDN Interconnection", draft-davie-cdni-framework-00 (work in progress), April 2012. [I-D. caulfield-cdni-metadata-core] M. Caulfield, and K. Leung, " Content Distribution Network Interconnection (CDNI) Core Metadata", draft-caulfield-cdni- metadata-core-00 (work in progress), October, 2011. Ni et all Expires January 9, 2013 [Page 10] Internet-Draft Criteria Metadata Extension July 2012 9. Acknowledgments This document was prepared using 2-Word-v2.0.template.dot. Authors' Addresses Wei Ni China Mobile Communication Corporation niwei@chinamobile.com Yana Bi China Mobile Communication Corporation biyana@chinamobile.com Yunfei Zhang China Mobile Communication Corporation zhangyunfei@chinamobile.com Ni et all Expires January 9, 2013 [Page 11]