Internet DRAFT - draft-ni-cdni-criteria-metadata-extension
draft-ni-cdni-criteria-metadata-extension
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
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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
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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].
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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 |
+------------+
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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.
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+------+ +------+ +------+
| 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.
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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
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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.
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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.
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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.
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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
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