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Routing Request Redirection for CDN Interconnection
draft-he-cdni-routing-request-redirection-01

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This is an older version of an Internet-Draft whose latest revision state is "Expired".
Authors Xiaoyan He , Spencer Dawkins , Ge Chen , Wei Ni , Yunfei Zhang
Last updated 2012-02-21 (Latest revision 2012-02-16)
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draft-he-cdni-routing-request-redirection-01
CDNI Working Group                                              Xiaoyan.He 
Internet Draft                                             Spencer.Dawkins 
Intended status: Standards Track                                    Huawei 
Expires: August 2012                                               Ge.Chen 
                                                             China Telecom 
                                                                    Wei.Ni
                                                              Yunfei.Zhang 
                                                               China Mobile 
                                                          February 22, 2012 
 
 
 
                                     
               Routing Request Redirection for CDN Interconnection 
                 draft-he-cdni-routing-request-redirection-01.txt 

Status of this Memo 

  This Internet-Draft is submitted in full conformance with the provisions of BCP 78 
  and BCP 79.  

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  This Internet-Draft will expire on August 22, 2012. 

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  Copyright (c) 2012 IETF Trust and the persons identified as the document authors. 
  All rights reserved. 

  This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating 
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  publication of this document. Please review these documents carefully, as they 
  describe your rights and restrictions with respect to this document. Code 
  Components extracted from this document must include Simplified BSD License text 
  as described in Section 4.e of the Trust Legal Provisions and are provided without 
  warranty as described in the Simplified BSD License. 
 
 
 
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Abstract 
  The Request Routing Interface comprises the asynchronous advertisement of 
  footprint and capabilities by a dCDN that allows a uCDN to decide whether to 
  redirect particular user requests to that dCDN; and the synchronous operation of 
  actually redirecting a user request. This document describes protocol for the part 
  of user requests redirection. 
 
Table of Contents 

   
  1. Introduction ..................................................... 2 
     1.1. Terminology .................................................3 
  2. Conventions used in this document.................................... 3 
  3. Interface function and operation overview ............................. 3 
     3.1. Discussion on protocol type for RRI ............................. 4 
        3.1.1. DNS based Request Routing Protocol ......................... 6 
           3.1.1.1. HTTP Redirection utilized by Downstream CDN ............. 6 
           3.1.1.2. DNS Redirection utilized by Downstream CDN .............. 7 
        3.1.2. HTTP based Request Routing Protocol......................... 8 
  4. Protocol Specification ............................................ 10 
  5. Security Considerations ........................................... 11 
  6. IANA Considerations .............................................. 12 
  7. References ...................................................... 12 
     7.1. Normative References ......................................... 12 
     7.2. Informative References ....................................... 12 
  8. Acknowledgments.................................................. 12 
   
1. Introduction 
  A Content Delivery Network(CDN) is a system of computers built on an   
  existing IP network which is used for large scale content delivery,  
  via prefetch or cache contents to its distributed computers close to  
  the end users, a CDN can improve access to the data it caches, reduce access 
  latency and improve end user's experience.    
      
  In recent years the volume of video and multimedia content delivered  
  over the internet is rapidly increasing. To accommodating this  
  increase, existing CDN providers are scaling up their infrastructure 
  and many Network Service Providers (NSPs) are deploying their own CDNs. Another 
  emerging requirement is CDN Interconnection (CDNI).  
  Several real world use cases are described in [I-D.draft-cdni-use- 
  cases] to prove the necessity for CDN interconnection. The most  
  frequently mentioned use case is via leveraging the collective CDN 
  footprint of interconnected standalone CDNs to achieve the goal of  
  delivering content to additional distributed end users regardless of their 
  location.   
      
  As there is no existing standard to facilitate CDN interconnection,  
 
 
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  IETF has established a working group to produce specifications needed. This draft 
  is written in response to the problem area described in [I-D.draft-cdni-problem-
  statement], when CDNs are interconnected as described in [I-D.draft-cdni-use-cases] 
  based on the requirements described in [I-D.draft-cdni-requirements], and using 
  the technology framework described in [I-D.davie-cdni-framework].   
      
  The purpose of this document is to define the protocol for synchronous redirection 
  operation of the request routing interface, which is one of the main building 
  blocks of the CDN interconnection architecture described in [I-D.draft-cdni-
  requirements]. 
   
1.1. Terminology 
  This document reuses the terminology defined in [I-D.draft-cdni- 
  problem-statement]. The term "Distinguished CDN Domain" defined in [I-D.davie-
  cdni-framework] also reused in this document.  
      
  The following terms are introduced by this document in addition:  
      
  DNS Redirection: The act of using DNS name resolution for the routing process of a 
  CDN. In DNS Redirection, the DNS resolver of the CDN makes the routing decision 
  based on a local policy and returns the result as the response of a DNS query 
  request to redirect a user agent to a new target. In CDNI, the result may point to 
  a surrogate of the CDN, another interconnected CDN etc.  
      
  HTTP Redirection: The act of using an HTTP redirection response to  
  redirect a user agent to a new target. The new target is the result  
  of the routing decision of a CDN at the time it receives a content  
  request via HTTP. In CDNI, the result may point to a surrogate of the CDN, another 
  interconnected CDN etc. 
   
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].  

3. Interface function and operation overview 
  The Request Routing Protocol is one of the main building blocks for 
  CDNI. The main function of the Request Routing Protocol is to allow 
  the Request-Routing systems in interconnected CDNs to communicate to facilitate 
  redirection of the request across CDNs.  
    
  The detailed requirements which the Request Routing Protocol need to   
  meet and priorities of those requirements are described in section 5,  
  [I-D.draft-cdni-requirements].  
      
  To enable the communications over the Request Routing Interface, the  
   two interconnected CDNs need to know each other's contact address(es). For example, 
   an Upstream CDN needs to know the contact address of a Downstream CDN to send a 
   query request based on HTTP for redirection preference, or a Downstream CDN needs 
   to know the contact address(es) of the upstream peer it should report its 
   capability information to.   
 
 
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  The contact address may be statically pre-configured, dynamically discovered via 
  control interface, or other means. However, they are not specified in this 
  document, as this is considered not in the scope of the CDNI Request Routing 
  Protocol. 
   
  The CDNI solution must support two request routing mechanisms. As  
  illustrated in section 3.2 and 3.4 of [I-D.davie-cdni-framework], the Iterative 
  Request Routing method does not invoke any interaction over the request routing 
  interface across interconnected CDNs. This document hence will not discuss 
  Iterative Request Routing further.   
   
  In the case of Recursive Request Routing, an Upstream CDN forwards a  
  routing request from a user agent to a Downstream CDN for surrogate  
  selection. The candidate protocols for these interactions are DNS and HTTP. 
  Moreover, the inside routing mechanisms used between the CDN and the user agent 
  (DNS and HTTP Redirection) of the two interconnected CDNs should also be taken 
  into account as they may affect the type of query request the Upstream CDN send to 
  a Downstream CDN and the information the Downstream CDN return in its query 
  response.  
   
3.1. Discussion on protocol type for RRI 
  The request routing process has several variants depending on the  
  factors including: 
    O Which routing mechanism is adopted by an Upstream CDN inside, DNS Redirection 
     or HTTP Redirection. 
     
    O Which protocol is adopted over the Request Routing Interface, DNS or HTTP. 
     
    O Which routing mechanism is adopted by a Downstream CDN inside, DNS Redirection 
     or HTTP Redirection. 
   
  All possible combinations and their validity are shown in Table 1.  
   +-------+---------+----------+------------ +-----------------------+  
   |CaseNO.|  uCDN   | RRI      |   dCDN      |       Note            |  
   |       | Received| Interface| Response    |                       |  
   |       |  Request|          |             |                       |  
   +-------+---------+----------+------------ +-----------------------+  
   |  1    |  DNS    | DNS based| DNS with IP | dCDN works in HTTP    |  
   |       |         |          |address of RR| Redirection mode,     |  
   |       |         |          |             |illustrated in section |  
   |       |         |          |             |3.1.1.1.               |  
   +-------+---------+----------+------------ +-----------------------+  
   |  2    |  DNS    | DNS based|  DNS with   | dCDN works in DNS     |  
   |       |         |          | hostname of | Redirection mode,     |  
   |       |         |          |    RR       | illustrated in section|  
   |       |         |          |             |3.1.1.2.               |  
   +-------+---------+----------+------------ +-----------------------+  
   |  3    |  DNS    |HTTP based| Invalid case|Protocol conversion    |  
   |       |         |          |             |occurs in uCDN,        |  
   |       |         |          |             | invalid case.         |  
 
 
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   +-------+---------+----------+------------ +-----------------------+  
   |  4    |  HTTP   |HTTP based| HTTP 302    | dCDN works in HTTP    |  
   |       |         |          | Redirection | Redirection mode,     |  
   |       |         |          |             |illustrated in section |  
   |       |         |          |             |3.1.2.                 |  
   +-------+---------+----------+------------ +-----------------------+  
   |  5    |  HTTP   |HTTP based|   DNS       | dCDN works in DNS     |  
   |       |         |          | Redirection | Redirection mode,     |  
   |       |         |          |             | invalid case.         |  
   +-------+---------+----------+------------ +-----------------------+  
   |  6    |  HTTP   |DNS  based| Invalid case| Protocol conversion   |  
   |       |         |          |             | occurs, invalid case. |  
   +-------+---------+----------+------------ +-----------------------+  
                    Table 1: Recursive Routing Cases  
 
  The rules to filter the cases and determine the validity of them are 
  discussed below. 
   
  The Upstream CDN must not perform protocol conversion (A DNS 
  query to an HTTP request or vice versa). To assist the routing 
  decision of a Downstream CDN, the Upstream CDN shall convey as much 
  information as possible to the Downstream CDN, e.g. URI of the 
  requested content, the client's location information. In the case of 
  HTTP to DNS conversion, a DNS request cannot convey all the 
  information an HTTP request contains. In the case of DNS to HTTP 
  conversion, a full HTTP URL cannot be constructed through a simple 
  domain name contained by a DNS query request. Hence it is concluded 
  that the protocol type used in the Request Routing Interface will be 
  consistent with the one the Upstream CDN received from the user 
  agent.  Case3, Case6 are invalid according to this rule. 
   
  The Downstream CDN can determine according to its local policy 
  a DNS Redirection or an HTTP Redirection to be adopted. When 
  receiving a DNS query request over the Request Routing Interface. 
  If DNS Redirection is selected, as the location information has 
  been changed to the Upstream CDN's when it proxies the DNS query 
  request, the Downstream CDN cannot get the user agent's location 
  information from the query request. The Downstream CDN sends a 
  response with a CNAME of the hostname of the Request Router, 
  so that the user agent issues another DNS query request which 
  will convey its location information as shown in case2. If HTTP 
  Redirection is selected, the Downstream CDN sends a response with 
  the IP address of its Request Router, so that it can receive a 
  subsequent content request based on HTTP containing the client's 
  location information, to allow selection of an appropriate surrogate 
  as shown in case1. 
 
  Based on filter rules above, Case 1, 2, and 4 are valid cases for 
  CDNI. The following section describes these cases in detail. 
 
   

 
 
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3.1.1. DNS based Request Routing Protocol 

  Editor's note: Whether mention invoke or application of content relevant metadata 
  in the request redirection procedure or just leave it to the framework document 
  should be determined. 

3.1.1.1. HTTP Redirection utilized by Downstream CDN 
  This example illustrates the CaseNo1 of Table 1. Based on local 
  policy, the Upstream CDN adopts the DNS Redirection with the user 
  agent while the Downstream CDN utilizes the HTTP Redirection. The 
  Downstream CDN should return the IP address in an RR. In this example,the 
  distinguished domain name of the Downstream CDN is "cdni.op-b.example". 
   
  Note: To simplify the presentation, the full URL of the HTTP GET 
  message is not shown in the example figures of this document. 
  Only the FQDN at the beginning of each URL is explicitly 
  presented, however the rest of the URL e.g. the path parameters contained in the 
  URL should be considered to be present. 
 
   End-User                      CDN B                     CDN A  
          |DNS video.cp.example     |                         |(1)  
          |-------------------------------------------------->|  
          |                         | DNS video.cp.example.   |   
          |                         |    cdni.op-b.example    |  
          |                         |<------------------------|(2)  
          |                         |IPaddr of B's Request Router  
          |                         |------------------------>|  
          |      IPaddr of B's Request Router                 |  
          |<--------------------------------------------------|(3)  
          |HTTP GET video.cp.example|                         |  
          |------------------------>|        (4)              |  
302 node1.cdni.op-b.example/video.cp.example                   |  
          |<------------------------|                         |  
        DNS node1.cdni.op-b.example |                         |  
          |------------------------>|                         |  
          |IP address of B's node1  |(5)                      |  
          |<----------------------- |                         |  
 HTTP GET node1.cdni.op-b.example/video.cp.example            |  
          |------------------------>|                         |  
          |Data                     |(6)                      |  
          |<------------------------|                         |  
          |                         |                         |  
    
           Figure 2 DNS based CDNI Recursive Request Routing 1  
  
                                      
  1. A Request Routing System of CDN A processes the DNS request for 
  its customer based on the domain video.cp.example and recognizes 
 
 
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  that the end-user is best served by another CDN, specifically 
  CDN B. Based on the pre-configured distinguished domain name of 
  CDN B and a negotiated rules for constructing a domain 
  name contained in a DNS query request over RRI that have been 
  negotiated with CDN B, the Request Routing System changes the domain name to CDN 
  B's domain name, with the CP's domain information, and acts as a proxy server 
  forwarding the DNS request to CDN B. 
   
  Note: For simplicity, the local DNS invoked in the procedure is 
  not shown. 
   
  2. Based on the local policy, CDN B determines that the routing 
  mechanism utilized internally is HTTP Redirection. CDN B returns 
  the IP address of a Request Router so that the RR get the 
  subsequent HTTP content request from the user agent. 
   
  3. CDN A proxy the response back to the user agent. 
   
  4. The user agent sends the content requests to the Request Router 
  of CDN B. Based on local routing decision policy, e.g. whether 
  content hits take the highest priority or location proximity 
  takes the highest priority, the Request Router selects a 
  delivery node to serve the user agent and returns an HTTP 302 
  message to redirect the content request. 
   
  5. The user agent performs a DNS lookup for the hostname of the 
  delivery node and gets the IP address of the node. 
   
  6. The user agent requests the content from CDN B's delivery node. 
  The node contains the content, so it sends the content to 
  the user agent. 
   

3.1.1.2. DNS Redirection utilized by Downstream CDN 
  This example illustrates the CaseNo2 of Table 1. Based on local 
  policy, the Upstream CDN and the Downstream CDN both utilize the DNS 
  Redirection inside with the user agent. As the Downstream CDN cannot get the user 
  agent's location information through the DNS request forwarded by the Upstream CDN, 
  in this case, the DNS resolver of the Downstream CDN is configured to return a 
  CNAME of the RR to make it receive another DNS query request sent by the user 
  agent/local DNS with information of the user's location. Again, the distinguished 
  domain name of the Downstream CDN is "cdni.op-b.example". 
 
   End-User                      CDN B                     CDN A  
           |DNS video.cp.example     |                         |(1)  
           |-------------------------------------------------->|  
           |                         | DNS video.cp.example.   |   
           |                         |    cdni.op-b.example    |  
           |                         |<------------------------|(2)  
           |                         |CNAME video.cp.example.  |  
           |                         |   rr.cdni.op-b.example  |  
           |                         |------------------------>|                     
 
 
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           CNAME video.cp.example.rr.cdni.op-b.example         |  
           |<--------------------------------------------------|(3)  
           |   DNS video.cp.example. |                         |  
           |    rr.cdni.op-b.example |                         |  
           |------------------------>|                         |  
         IP address of delivery node |(4)                      |  
           |<------------------------|                         |  
           |HTTP GET video.cp.example|                         |  
           |------------------------>|                         |  
           |Data                     |(5)                      |  
           |<------------------------|                         |  
           |                         |                         |  
  
          Figure 3 DNS based CDNI Recursive Request Routing 2  
                                     
  1. A Request Routing System of CDN A processes the DNS request for 
  its customer based on the domain video.cp.example and recognizes 
  that the end-user is best served by another CDN, specifically 
  CDN B. Based on the pre-configured distinguished domain name of 
  CDN B and rules that have been negotiated with CDN B that 
  describe how to construct a domain name contained in a DNS query 
  request over RRI, the Request Routing System changes the domain 
  name to CDN B's domain name accompanying with the CP's domain 
  information and acts as a proxy server forwarding the DNS 
  request to CDN B. 
   
  Note: For simplicity, the local DNS invoked in the procedure is 
  not shown. 
   
  2. CDN B recognizes that the request is from a peer CDN rather than 
  a user agent by the distinguished domain name. Based on the 
  local policy, CDN B determines that the routing mechanism 
  utilized internally is DNS Redirection. CDN B returns the CNAME 
  of a Request Router so that the user agent will send another DNS 
  query request to get the user agent's location information. 
   
  3. CDN A proxy the response back to the user agent. 
   
  4. The user agent sends the content requests to the Request Router 
  of CDN B based on DNS with the CNAME of the RR. Based on local 
  routing decision policy, the Request Router selects a delivery 
  node to serve the user agent and returns IP address of the node. 
   
  5. The user agent requests the content from CDN B's delivery node, 
  the node holds the content at the time and send the content to 
  the user agent. 
   

3.1.2. HTTP based Request Routing Protocol 
  This example illustrates the CaseNo4 of Table 1. Based on local 

 
 
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  policy, the Upstream CDN and the Downstream CDN both utilize the HTTP Redirection 
  inside with the user agent. The Upstream CDN shall provide as much information as 
  possible to the Downstream to assist making the routing decision. For example, it 
  includes the content URI and the user's location information etc. 
    
    
        End-User                   CDN B                    CDN A  
           |DNS video.cp.example     |                         |  
           |-------------------------------------------------->|  
           |                         |                         | (1)  
           |IPaddr of A's Request Router                       |  
           |<--------------------------------------------------|  
           |HTTP GET video.cp.example|                         |  
           |-------------------------------------------------->|(2)  
           |        HTTP GET cdni.op-b.example/video.cp.example|  
           |                         |<------------------------| (3)  
           |           302 node1.cdni.op-b.example/video.cp.example  
           |                         |------------------------>|  
           |        302 node1.cdni.op-b.example/video.cp.example  
           |<--------------------------------------------------|(4)  
         DNS node1.cdni.op-b.example |                         |  
           |------------------------>|                         |  
           |IP address of B's node1  |(5)                      |  
           |<----------------------- |                         |  
HTTP GET node1.cdni.op-b.example/video.cp.example              |  
           |-----------------------> |                         |  
           |Data                     | (6)                     | 
           |<------------------------|                         |  
           |                         |                         |  
 
         Figure 4 HTTP protocol based CDNI Recursive Request Routing 
1. A DNS resolver for CDN A processes the DNS request for its 
customer based on the domain video.cp.example.  Based on local 
policy, HTTP Redirection is adopted for this request. Hence it 
returns the IP address of a Request Router in CDN A. 
 
2. A Request Router of CDN A processes the user agent's content 
request and recognizes that the end-user is best served by 
another CDN, specifically CDN B. Based on pre-configuration 
or other means of discovery, the Request Router pushes the 
distinguished domain name of CDN B onto the original URL and 
acts as a proxy server forwarding the request to CDN B's Request 
Router. It also appends an X-Forwarded-For header into the 
request with the value set to the user's IP address extracted 
from the IP package header of the HTTP request it received. 
 
3. Based on local routing decision policy, e.g. whether content 
hits take the highest priority or location proximity takes the 
highest priority, the Request Router of CDN B select a delivery 
 
 
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node for the end user and returns an HTTP 302 message to 
redirect the content request to the node. 
 
4. CDN A proxies the response back to the user agent. 
 
5. The user agent performs a DNS lookup for the hostname of the 
delivery node and gets the IP address of the node. 
 
6. The user agent requests the content from CDN B's delivery node. 
Since the node holds the content, it sends the content to 
the user agent. 
   

4. Protocol Specification 
This section specifies how the Request Routing Protocol enables the Upstream CDN 
acting as a proxy server to communicate with the downstream CDN to implement routing 
redirection. 
 
4.1.1. Recursive Request Routing  
 
4.1.1.1. DNS based Request Routing Protocol  
 
4.1.1.1.1. Upstream CDN Behavior  
 
Upon receiving a DNS query request from a user agent, the Request 
Routing System of the Upstream CDN SHALL first determine an inside routing mechanism 
according to local policy. In case of DNS Redirection is leveraged, based on the local 
routing policy, if it is aware that the user is best served by another CDN, the 
Upstream CDN SHALL select a 
Downstream CDN and forward the DNS request to the Downstream CDN. When 
HTTP Redirection is adopted, the Upstream CDN SHALL respond with the 
address of a Request Router of the Upstream CDN. 
 
The QNAME contained in the DNS query request which is forwarded to 
the Downstream CDN SHALL be constructed by the rules negotiated by 
the two interconnected CDNs and based on the distinguished domain 
name of the Downstream CDN. 
 
Upon receiving a response from the Downstream CDN, the Request 
Routing System of the Upstream CDN shall forward it back to the user 
agent with the DNS payload unchanged. 
 
4.1.1.1.2. Downstream CDN Behavior  
 
Upon receiving a DNS query request, the Downstream CDN SHALL first 
identify that this is a request for CDNI based on the distinguished 
domain name contained in the query request, and extracts the content 
provider's domain name. It then SHALL determine an inside routing mechanism according 
to local routing policy. 
 
Note: The local routing policy may take into account the CP's policy 
if existed identified by the CP's domain name. 
 

 
 
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In case of DNS Redirection, it SHALL select a request router and 
return a response containing a CNAME with the hostname of the request 
router. 
 
In case of HTTP Redirection, it SHALL select a request router and 
return a response containing the IP address of the Request Router. 
 
4.1.1.2. HTTP based Request Routing Protocol  
 
4.1.1.2.1. Upstream CDN Behavior  
 
Upon receiving an HTTP GET request from a user agent for specific 
content, based on the local routing policy, if it is determined that 
the user is best served by another CDN, the Request Router of the 
Upstream CDN SHALL select a Downstream CDN for the end user, insert 
an X-Forwarded-For header into the request with the value set to the 
User Agent's IP address, augment the original URL with the 
distinguished domain name of the Downstream CDN in front of it, and 
then forward the request to the elected Downstream CDN. 
 
After receiving an HTTP "302" redirection response from the 
Downstream CDN, the Upstream CDN SHALL forward it back to the user 
agent. 
 
4.1.1.2.2. Downstream CDN Behavior 
 
Upon receiving an HTTP GET request, the Downstream CDN SHALL select a 
delivery node for the user based on the local routing policy. 
If the user's location information is required to make the routing 
decision, it SHALL obtain that from an X-Forwarded-For header if this 
hearder exists. The Downstream CDN SHALL then return a response with 
a 302 Redirection message. The Location header's value is constructed 
by truncating the CDN B's domain name from the original URL in the 
request it received, and inserting the host name of the selected delivery node onto 
the front of the remaining URL. 
 
4.1.2. Iterative Request Routing  
 
Note: Whether any content relative to Iterative Request Routing should 
     be added here is to be determined by the CDNI working group. 
  

5. Security Considerations 
In HTTP based Recursive Request Routing, the end user's web 
browsers will not send cookies if the content request is redirected 
to a URL in a different domain rather than the original CP's domain, 
e.g. the Downstream CDN's domain. If the browser is expected to send 
any cookies associated with the original CP's domain, this will cause 
problem that the CP's policy is not enforced by the CDN. 
 
The section 5.2 of draft [I-D.draft-peterson-cdni-strawman] has 
discussed a similar question and given a solution. 
 
 
 
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6. IANA Considerations 
This document makes no request of IANA. 
 
7. References 

7.1. 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. 

7.2. Informative References 
 [I-D.draft-cdni-use-cases]  
         "Use Cases for Content Delivery Network Interconnection",  
           Gilles Bertrand, Stephan Emile, Grant Watson, Trevor  
           Burbridge, Philip Eardley, Kevin Ma, 22-Sep-11, <draft-ietf- 
           cdni-use-cases-03.txt>.  
    
  [I-D.draft-cdni-problem-statement]  
         "Content Distribution Network Interconnection (CDNI) Problem  
           Statement", Ben Niven-Jenkins, Francois Faucheur, Nabil  
           Bitar, 9-Sep-11, <draft-ietf-cdni-problem-statement-03.txt>.  
  [I-D.draft-cdni-requirements]  
          "Content Distribution Network Interconnection (CDNI)  
          Requirements", Kent Leung, Yiu Lee, 9-Sep-11, <draft-ietf- 
          cdni-requirements-02.txt>.  
       
  [I-D.draft-peterson-cdni-strawman]   
          "A Simple Approach to CDN Interconnection", Larry   
          Peterson, John Hartman, 18-May-11,<draft-peterson-  
          cdni-strawman-01.txt,.pdf>.  
       
  [I-D.davie-cdni-framework]  
           Davie, B. and L. Peterson, "Framework for CDN  
           Interconnection", draft-davie-cdni-framework-01 (work in  
           progress), July 2011. 
   

8. Acknowledgments 

  This document was prepared using 2-Word-v2.0.template.dot. 

 
 
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Internet-Draft               Routing Redirection                 February 2012 
   

Authors?Addresses 
Xiaoyan He 
Huawei 
B2, Huawei Industrial Base, 518129 
China 
 
Email: hexiaoyan@huawei.com 
 
 
Spencer Dawkins 
Huawei 
 
Email: spencer.dawkins@wondermaster.com 
 
 
Ge Chen 
China Telecom 
109 West Zhongshan Ave,Tianhe District,Guangzhou,P.R.C 
 
Email: cheng@gsta.com 

 
Wei Ni 
China Mobile 
No.32 Xuanwumen West Street Xicheng District Beijing, 100053 
China 
 
Email: niwei@chinamobile.com 

Yunfei Zhang 
China Mobile 
    
Email: zhangyunfei@chinamobile.com 
 

 
 
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