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diff --git a/doc/rfc/rfc3466.txt b/doc/rfc/rfc3466.txt new file mode 100644 index 0000000..d8aa463 --- /dev/null +++ b/doc/rfc/rfc3466.txt @@ -0,0 +1,955 @@ + + + + + + +Network Working Group M. Day +Request for Comments: 3466 Cisco +Category: Informational B. Cain + Storigen + G. Tomlinson + Tomlinson Group + P. Rzewski + Media Publisher, Inc. + February 2003 + + + A Model for Content Internetworking (CDI) + +Status of this Memo + + This memo provides information for the Internet community. It does + not specify an Internet standard of any kind. Distribution of this + memo is unlimited. + +Copyright Notice + + Copyright (C) The Internet Society (2003). All Rights Reserved. + +Abstract + + Content (distribution) internetworking (CDI) is the technology for + interconnecting content networks, sometimes previously called + "content peering" or "CDN peering". A common vocabulary helps the + process of discussing such interconnection and interoperation. This + document introduces content networks and content internetworking, and + defines elements for such a common vocabulary. + +Table of Contents + + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 + 2. Content Networks . . . . . . . . . . . . . . . . . . . . . . 2 + 2.1 Problem Description . . . . . . . . . . . . . . . . . 3 + 2.2 Caching Proxies. . . . . . . . . . . . . . . . . . . . 4 + 2.3 Server Farms . . . . . . . . . . . . . . . . . . . . . 5 + 2.4 Content Distribution Networks. . . . . . . . . . . . . 6 + 2.4.1 Historic Evolution of CDNs . . . . . . . . . . . 8 + 2.4.2 Describing CDN Value: Scale and Reach. . . . . . 8 + 3. Content Network Model Terms . . . . . . . . . . . . . . . . 9 + 4. Content Internetworking . . . . . . . . . . . . . . . . . . 12 + 5. Content Internetworking Model Terms . . . . . . . . . . . . 12 + 6. Security Considerations . . . . . . . . . . . . . . . . . . 15 + 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 15 + 8. Normative References . . . . . . . . . . . . . . . . . . . . 16 + + + +Day, et al. Informational [Page 1] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + + 9. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 16 + 10. Full Copyright Statement . . . . . . . . . . . . . . . . . . 17 + +1. Introduction + + Content networks are of increasing importance to the overall + architecture of the Web. This document presents a vocabulary for use + in developing technology for interconnecting content networks, or + "content internetworking". + + The accepted name for the technology of interconnecting content + networks is "content internetworking". For historical reasons, we + abbreviate this term using the acronym CDI (from "content + distribution internetworking"). Earlier names relied on analogy with + peering and interconnection of IP networks; thus we had "content + peering" and "CDN peering". All of these other names are now + deprecated, and we have worked to establish consistent usage of + "content internetworking" and "CDI" throughout the documents of the + IETF CDI group. + + The terminology in this document builds from the previous taxonomy of + web caching and replication in RFC 3040 [3]. In particular, we have + attempted to avoid the use of the common terms "proxies" or "caches" + in favor of more specific terms defined by that document, such as + "caching proxy". + + Section 2 provides background on content networks. Section 3 + introduces the terms used for elements of a content network and + explains how those terms are used. Section 4 provides additional + background on interconnecting content networks, following which + Section 5 introduces additional terms and explains how those + internetworking terms are used. + +2. Content Networks + + The past several years have seen the evolution of technologies + centered around "content". Protocols, appliances, and entire markets + have been created exclusively for the location, download, and usage + tracking of content. Some sample technologies in this area have + included web caching proxies, content management tools, intelligent + "web switches", and advanced log analysis tools. + + + + + + + + + + +Day, et al. Informational [Page 2] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + + When used together, these tools form new types of networks, dubbed + "content networks". Whereas network infrastructures have + traditionally processed information at layers 1 through 3 of the OSI + stack, content networks include network infrastructure that exists in + layers 4 through 7. Whereas lower-layer network infrastructures + centered on the routing, forwarding, and switching of frames and + packets, content networks deal with the routing and forwarding of + requests and responses for content. The units of transported data in + content networks, such as images, movies, or songs, are often very + large and may span hundreds or thousands of packets. + + Alternately, content networks can be seen as a new virtual overlay to + the OSI stack: a "content layer", to enable richer services that rely + on underlying elements from all 7 layers of the stack. Whereas + traditional applications, such as file transfer (FTP), relied on + underlying protocols such as TCP/IP for transport, overlay services + in content networks rely on layer 7 protocols such as HTTP or RTSP + for transport. + + The proliferation of content networks and content networking + capabilities gives rise to interest in interconnecting content + networks and finding ways for distinct content networks to cooperate + for better overall service. + +2.1 Problem Description + + Content networks typically play some role in solving the "content + distribution problem". Abstractly, the goal in solving this problem + is to arrange a rendezvous between a content source at an origin + server and a content sink at a viewer's user agent. In the trivial + case, the rendezvous mechanism is that every user agent sends every + request directly to the origin server named in the host part of the + URL identifying the content. + + As the audience for the content source grows, so do the demands on + the origin server. There are a variety of ways in which the trivial + system can be modified for better performance. The apparent single + logical server may in fact be implemented as a large "farm" of server + machines behind a switch. Both caching proxies and reverse caching + proxies can be deployed between the client and server, so that + requests can be satisfied by some cache instead of by the server. + + For the sake of background, several sample content networks are + described in the following sections that each attempt to address this + problem. + + + + + + +Day, et al. Informational [Page 3] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + +2.2 Caching Proxies + + A type of content network that has been in use for several years is a + caching proxy deployment. Such a network might typically be employed + by an ISP for the benefit of users accessing the Internet, such as + through dial or cable modem. + + In the interest of improving performance and reducing bandwidth + utilization, caching proxies are deployed close to the users. These + users are encouraged to send their web requests through the caches + rather than directly to origin servers, such as by configuring their + browsers to do so. When this configuration is properly done, the + user's entire browsing session goes through a specific caching proxy. + That caching proxy will therefore contain the "hot set" of all + Internet content being viewed by all of the users of that caching + proxy. + + When a request is being handled at a caching proxy on behalf of a + user, other decisions may be made, such as: + + o A provider that deploys caches in many geographically diverse + locations may also deploy regional parent caches to further + aggregate user requests and responses. This may provide + additional performance improvement and bandwidth savings. When + parents are included, this is known as hierarchical caching. + + o Using rich parenting protocols, redundant parents may be deployed + such that a failure in a primary parent is detected and a backup + is used instead. + + o Using similar parenting protocols, requests may be partitioned + such that requests for certain content domains are sent to a + specific primary parent. This can help to maximize the efficient + use of caching proxy resources. + + + + + + + + + + + + + + + + + +Day, et al. Informational [Page 4] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + + The following diagram depicts a hierarchical cache deployment as + described above: + + ^ ^ + | | requests to + | | origin servers + | | + -------- -------- + |parent| |parent| + |cache | |cache | + |proxy | |proxy | + -------- -------- + ^ ^ + requests for \ / requests for + foo.com \ / bar.com + content \ / content + \ / + ------- ------- ------- ------- + |edge | |edge | |edge | |edge | + |cache| |cache| |cache| |cache| + |proxy| |proxy| |proxy| |proxy| + ------- ------- ------- ------- + ^ + | all content + | requests + | for this + | client + | + -------- + |client| + -------- + + Note that this diagram shows only one possible configuration, but + many others are also useful. In particular, the client may be able + to communicate directly with multiple caching proxies. RFC 3040 [3] + contains additional examples of how multiple caching proxies may be + used. + +2.3 Server Farms + + Another type of content network that has been in widespread use for + several years is a server farm. A typical server farm makes use of a + so-called "intelligent" or "content" switch (i.e., one that uses + information in OSI layers 4-7). The switch examines content requests + and dispatches them among a (potentially large) group of servers. + + + + + + +Day, et al. Informational [Page 5] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + + Some of the goals of a server farm include: + + o Creating the impression that the group of servers is actually a + single origin site. + + o Load-balancing of requests across all servers in the group. + + o Automatic routing of requests away from servers that fail. + + o Routing all requests for a particular user agent's session to the + same server, in order to preserve session state. + + The following diagram depicts a simple server farm deployment: + + --------- --------- --------- --------- + |content| |content| |content| |content| + |server | |server | |server | |server | + | | | | | | | | + --------- --------- --------- --------- + ^ ^ + request from \ / request from + client A \ / client B + \ / + ------------- + | L4-L7 | + | switch | + ------------- + ^ ^ + / \ + / \ + / \ + request from request from + client A client B + + A similar style of content network (that is, deployed close to + servers) may be constructed with surrogates [3] instead of a switch. + +2.4 Content Distribution Networks + + Both hierarchical caching and server farms are useful techniques, but + have limits. Server farms can improve the scalability of the origin + server. However, since the multiple servers and other elements are + typically deployed near the origin server, they do little to improve + performance problems that are due to network congestion. Caching + proxies can improve performance problems due to network congestion + (since they are situated near the clients) but they cache objects + based on client demand. Caching based on client demand performs + poorly if the requests for a given object, while numerous in + + + +Day, et al. Informational [Page 6] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + + aggregate, are spread thinly among many different caching proxies. + (In the worst case, an object could be requested n times via n + distinct caching proxies, causing n distinct requests to the origin + server -- or exactly the same behavior that would occur without any + caching proxies in place.) + + Thus, a content provider with a popular content source can find that + it has to invest in large server farms, load balancing, and high- + bandwidth connections to keep up with demand. Even with those + investments, the user experience may still be relatively poor due to + congestion in the network as a whole. + + To address these limitations, another type of content network that + has been deployed in increasing numbers in recent years is the CDN + (Content Distribution Network or Content Delivery Network). A CDN + essentially moves server-farm-like configurations out into network + locations more typically occupied by caching proxies. A CDN has + multiple replicas of each content item being hosted. A request from + a browser for a single content item is directed to a "good" replica, + where "good" usually means that the item is served to the client + quickly compared to the time it would take fetch it from the origin + server, with appropriate integrity and consistency. Static + information about geographic locations and network connectivity is + usually not sufficient to do a good job of choosing a replica. + Instead, a CDN typically incorporates dynamic information about + network conditions and load on the replicas, directing requests so as + to balance the load. + + Compared to using servers and surrogates in a single data center, a + CDN is a relatively complex system encompassing multiple points of + presence, in locations that may be geographically far apart. + Operating a CDN is not easy for a content provider, since a content + provider wants to focus its resources on developing high-value + content, not on managing network infrastructure. Instead, a more + typical arrangement is that a network service provider builds and + operates a CDN, offering a content distribution service to a number + of content providers. + + A CDN enables a service provider to act on behalf of the content + provider to deliver copies of origin server content to clients from + multiple diverse locations. The increase in number and diversity of + location is intended to improve download times and thus improve the + user experience. A CDN has some combination of a content-delivery + infrastructure, a request-routing infrastructure, a distribution + infrastructure, and an accounting infrastructure. The content- + delivery infrastructure consists of a set of "surrogate" servers [3] + that deliver copies of content to sets of users. The request-routing + infrastructure consists of mechanisms that move a client toward a + + + +Day, et al. Informational [Page 7] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + + rendezvous with a surrogate. The distribution infrastructure + consists of mechanisms that move content from the origin server to + the surrogates. Finally, the accounting infrastructure tracks and + collects data on request-routing, distribution, and delivery + functions within the CDN. + + The following diagram depicts a simple CDN as described above: + + ---------- ---------- + |request-| |request-| + |routing | |routing | + | system | | system | + ---------- ---------- + ^ | + (1) client's | | (2) response + content | | indicating + request | | location of ----------- + | | content |surrogate| + | | ----------- + ----------- | | + |surrogate| | | ----------- + ----------- | | |surrogate| + | | ----------- + | | ^ + | v / (3) client opens + client--- connection to + retrieve content + +2.4.1 Historic Evolution of CDNs + + The first important use of CDNs was for the distribution of heavily- + requested graphic files (such as GIF files on the home pages of + popular servers). However, both in principle and increasingly in + practice, a CDN can support the delivery of any digital content -- + including various forms of streaming media. For a streaming media + CDN (or media distribution network or MDN), the surrogates may be + operating as splitters (serving out multiple copies of a stream). + The splitter function may be instead of, or in addition to, a role as + a caching proxy. However, the basic elements defined in this model + are still intended to apply to the interconnection of content + networks that are distributing streaming media. + +2.4.2 Describing CDN Value: Scale and Reach + + There are two fundamental elements that give a CDN value: outsourcing + infrastructure and improved content delivery. A CDN allows multiple + surrogates to act on behalf of an origin server, therefore removing + the delivery of content from a centralized site to multiple and + + + +Day, et al. Informational [Page 8] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + + (usually) highly distributed sites. We refer to increased aggregate + infrastructure size as "scale". In addition, a CDN can be + constructed with copies of content near to end users, overcoming + issues of network size, network congestion, and network failures. We + refer to increased diversity of content locations as "reach". + + In a typical (non-internetworked) CDN, a single service provider + operates the request-routers, the surrogates, and the content + distributors. In addition, that service provider establishes + (business) relationships with content publishers and acts on behalf + of their origin sites to provide a distributed delivery system. The + value of that CDN to a content provider is a combination of its scale + and its reach. + +3. Content Network Model Terms + + This section consists of the definitions of a number of terms used to + refer to roles, participants, and objects involved in content + networks. Although the following uses many terms that are based on + those used in RFC 2616 [1] or RFC 3040 [3], there is no necessary + connection to HTTP or web caching technology. Content + internetworking and this vocabulary are applicable to other protocols + and styles of content delivery. + + Phrases in upper-case refer to other defined terms. + + ACCOUNTING + Measurement and recording of DISTRIBUTION and DELIVERY activities, + especially when the information recorded is ultimately used as a + basis for the subsequent transfer of money, goods, or obligations. + + ACCOUNTING SYSTEM + A collection of CONTENT NETWORK ELEMENTS that supports ACCOUNTING + for a single CONTENT NETWORK. + + AUTHORITATIVE REQUEST-ROUTING SYSTEM + The REQUEST-ROUTING SYSTEM that is the correct/final authority for + a particular item of CONTENT. + + CDN + Content Delivery Network or Content Distribution Network. A type + of CONTENT NETWORK in which the CONTENT NETWORK ELEMENTS are + arranged for more effective delivery of CONTENT to CLIENTS. + Typically a CDN consists of a REQUEST-ROUTING SYSTEM, SURROGATES, + a DISTRIBUTION SYSTEM, and an ACCOUNTING SYSTEM. + + + + + + +Day, et al. Informational [Page 9] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + + CLIENT + A program that sends CONTENT REQUESTS and receives corresponding + CONTENT RESPONSES. (Note: this is similar to the definition in + RFC 2616 [1] but we do not require establishment of a connection.) + + CONTENT + Any form of digital data, CONTENT approximately corresponds to + what is referred to as an "entity" in RFC 2616 [1]. One important + form of CONTENT with additional constraints on DISTRIBUTION and + DELIVERY is CONTINUOUS MEDIA. + + CONTENT NETWORK + An arrangement of CONTENT NETWORK ELEMENTS, controlled by a common + management in some fashion. + + CONTENT NETWORK ELEMENT + A network device that performs at least some of its processing by + examining CONTENT-related parts of network messages. In IP-based + networks, a CONTENT NETWORK ELEMENT is a device whose processing + depends on examining information contained in IP packet bodies; + network elements (as defined in RFC 3040) examine only the header + of an IP packet. Note that many CONTENT NETWORK ELEMENTS do not + examine or even see individual IP packets, instead receiving the + body of one or more packets assembled into a message of some + higher-level protocol. + + CONTENT REQUEST + A message identifying a particular item of CONTENT to be + delivered. + + CONTENT RESPONSE + A message containing a particular item of CONTENT, identified in a + previous CONTENT REQUEST. + + CONTENT SIGNAL + A message delivered through a DISTRIBUTION SYSTEM that specifies + information about an item of CONTENT. For example, a CONTENT + SIGNAL can indicate that the ORIGIN has a new version of some + piece of CONTENT. + + CONTINUOUS MEDIA + CONTENT where there is a timing relationship between source and + sink; that is, the sink must reproduce the timing relationship + that existed at the source. The most common examples of + CONTINUOUS MEDIA are audio and motion video. CONTINUOUS MEDIA can + be real-time (interactive), where there is a "tight" timing + + + + + +Day, et al. Informational [Page 10] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + + relationship between source and sink, or streaming (playback), + where the relationship is less strict. [Note: This definition is + essentially identical to the definition of continuous media in + [2]] + + DELIVERY + The activity of providing a PUBLISHER's CONTENT, via CONTENT + RESPONSES, to a CLIENT. Contrast with DISTRIBUTION and REQUEST- + ROUTING. + + DISTRIBUTION + The activity of moving a PUBLISHER's CONTENT from its ORIGIN to + one or more SURROGATEs. DISTRIBUTION can happen either in + anticipation of a SURROGATE receiving a REQUEST (pre-positioning) + or in response to a SURROGATE receiving a REQUEST (fetching on + demand). Contrast with DELIVERY and REQUEST-ROUTING. + + DISTRIBUTION SYSTEM + A collection of CONTENT NETWORK ELEMENTS that support DISTRIBUTION + for a single CONTENT NETWORK. The DISTRIBUTION SYSTEM also + propagates CONTENT SIGNALs. + + ORIGIN + The point at which CONTENT first enters a DISTRIBUTION SYSTEM. + The ORIGIN for any item of CONTENT is the server or set of servers + at the "core" of the distribution, holding the "master" or + "authoritative" copy of that CONTENT. (Note: We believe this + definition is compatible with that for "origin server" in RFC 2616 + [1] but includes additional constraints useful for CDI.) + + PUBLISHER + The party that ultimately controls the CONTENT and its + distribution. + + REACHABLE SURROGATES + The collection of SURROGATES that can be contacted via a + particular DISTRIBUTION SYSTEM or REQUEST-ROUTING SYSTEM. + + REQUEST-ROUTING + The activity of steering or directing a CONTENT REQUEST from a + USER AGENT to a suitable SURROGATE. + + REQUEST-ROUTING SYSTEM + A collection of CONTENT NETWORK ELEMENTS that support REQUEST- + ROUTING for a single CONTENT NETWORK. + + + + + + +Day, et al. Informational [Page 11] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + + SERVER + A program that accepts CONTENT REQUESTS and services them by + sending back CONTENT RESPONSES. Any given program may be capable + of being both a client and a server; our use of these terms refers + only to the role being performed by the program. [Note: this is + adapted from a similar definition in RFC 2616 [1].] + + SURROGATE + A delivery server, other than the ORIGIN. Receives a CONTENT + REQUEST and delivers the corresponding CONTENT RESPONSE. [Note: + this is a different definition from that in RFC 3040 [3], which + appears overly elaborate for our purposes. A "CDI surrogate" is + always an "RFC 3040 surrogate"; we are not sure if the reverse is + true.] + + USER AGENT + The CLIENT which initiates a REQUEST. These are often browsers, + editors, spiders (web-traversing robots), or other end user tools. + [Note: this definition is identical to the one in RFC 2616 [1].] + +4. Content Internetworking + + There are limits to how large any one network's scale and reach can + be. Increasing either scale or reach is ultimately limited by the + cost of equipment, the space available for deploying equipment, + and/or the demand for that scale/reach of infrastructure. Sometimes + a particular audience is tied to a single service provider or a small + set of providers by constraints of technology, economics, or law. + Other times, a network provider may be able to manage surrogates and + a distribution system, but may have no direct relationship with + content providers. Such a provider wants to have a means of + affiliating their delivery and distribution infrastructure with other + parties who have content to distribute. + + Content internetworking allows different content networks to share + resources so as to provide larger scale and/or reach to each + participant than they could otherwise achieve. By using commonly + defined protocols for content internetworking, each content network + can treat neighboring content networks as "black boxes", allowing + them to hide internal details from each other. + +5. Content Internetworking Model Terms + + This section consists of the definitions of a number of terms used to + refer to roles, participants, and objects involved in internetworking + content networks. The purpose of this section is to identify common + terms and provide short definitions. + + + + +Day, et al. Informational [Page 12] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + + ACCOUNTING INTERNETWORKING + Interconnection of two or more ACCOUNTING SYSTEMS so as to enable + the exchange of information between them. The form of ACCOUNTING + INTERNETWORKING required may depend on the nature of the + NEGOTIATED RELATIONSHIP between the peering parties -- in + particular, on the value of the economic exchanges anticipated. + + ADVERTISEMENT + Information about resources available to other CONTENT NETWORKS, + exchanged via CONTENT INTERNETWORKING GATEWAYS. Types of + ADVERTISEMENT include AREA ADVERTISEMENTS, CONTENT ADVERTISEMENTS, + and DISTRIBUTION ADVERTISEMENTS. + + AREA ADVERTISEMENT + ADVERTISEMENT from a CONTENT NETWORK's REQUEST-ROUTING SYSTEM + about aspects of topology, geography and performance of a CONTENT + NETWORK. Contrast with CONTENT ADVERTISEMENT, DISTRIBUTION + ADVERTISEMENT. + + BILLING ORGANIZATION + An entity that operates an ACCOUNTING SYSTEM to support billing + within a NEGOTIATED RELATIONSHIP with a PUBLISHER. + + CONTENT ADVERTISEMENT + ADVERTISEMENT from a CONTENT NETWORK's REQUEST-ROUTING SYSTEM + about the availability of one or more collections of CONTENT on a + CONTENT NETWORK. Contrast with AREA ADVERTISEMENT, DISTRIBUTION + ADVERTISEMENT + + CONTENT DESTINATION + A CONTENT NETWORK or DISTRIBUTION SYSTEM that is accepting CONTENT + from another such network or system. Contrast with CONTENT + SOURCE. + + CONTENT INTERNETWORKING GATEWAY (CIG) + An identifiable element or system through which a CONTENT NETWORK + can be interconnected with others. A CIG may be the point of + contact for DISTRIBUTION INTERNETWORKING, REQUEST-ROUTING + INTERNETWORKING, and/or ACCOUNTING INTERNETWORKING, and thus may + incorporate some or all of the corresponding systems for the + CONTENT NETWORK. + + CONTENT REPLICATION + The movement of CONTENT from a CONTENT SOURCE to a CONTENT + DESTINATION. Note that this is specifically the movement of + CONTENT from one network to another. There may be similar or + different mechanisms that move CONTENT around within a single + network's DISTRIBUTION SYSTEM. + + + +Day, et al. Informational [Page 13] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + + CONTENT SOURCE + A CONTENT NETWORK or DISTRIBUTION SYSTEM that is distributing + CONTENT to another such network or system. Contrast with CONTENT + DESTINATION. + + DISTRIBUTION ADVERTISEMENT + An ADVERTISEMENT from a CONTENT NETWORK's DISTRIBUTION SYSTEM to + potential CONTENT SOURCES, describing the capabilities of one or + more CONTENT DESTINATIONS. Contrast with AREA ADVERTISEMENT, + CONTENT ADVERTISEMENT. + + DISTRIBUTION INTERNETWORKING + Interconnection of two or more DISTRIBUTION SYSTEMS so as to + propagate CONTENT SIGNALS and copies of CONTENT to groups of + SURROGATES. + + ENLISTED + Describes a CONTENT NETWORK that, as part of a NEGOTIATED + RELATIONSHIP, has accepted a DISTRIBUTION task from another + CONTENT NETWORK, has agreed to perform REQUEST-ROUTING on behalf + of another CONTENT NETWORK, or has agreed to provide ACCOUNTING + data to another CONTENT NETWORK. Contrast with ORIGINATING. + + INJECTION + A "send-only" form of DISTRIBUTION INTERNETWORKING that takes + place from an ORIGIN to a CONTENT DESTINATION. + + INTER- + Describes activity that involves more than one CONTENT NETWORK + (e.g., INTER-CDN). Contrast with INTRA-. + + INTRA- + Describes activity within a single CONTENT NETWORK (e.g., INTRA- + CDN). Contrast with INTER-. + + NEGOTIATED RELATIONSHIP + A relationship whose terms and conditions are partially or + completely established outside the context of CONTENT NETWORK + internetworking protocols. + + ORIGINATING + Describes a CONTENT NETWORK that, as part of a NEGOTIATED + RELATIONSHIP, submits a DISTRIBUTION task to another CONTENT + NETWORK, asks another CONTENT NETWORK to perform REQUEST-ROUTING + on its behalf, or asks another CONTENT NETWORK to provide + ACCOUNTING data. Contrast with ENLISTED. + + + + + +Day, et al. Informational [Page 14] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + + REMOTE CONTENT NETWORK + A CONTENT NETWORK able to deliver CONTENT for a particular REQUEST + that is not the AUTHORITATIVE REQUEST-ROUTING SYSTEM for that + REQUEST. + + REQUEST-ROUTING INTERNETWORKING + Interconnection of two or more REQUEST-ROUTING SYSTEMS so as to + increase the number of REACHABLE SURROGATES for at least one of + the interconnected systems. + +6. Security Considerations + + This document defines terminology and concepts for content + internetworking. The terminology itself does not introduce any + security-related issues. The implementation of content + internetworking concepts does raise some security-related issues, + which we identify in broad categories below. Other CDI documents + will address their specific security-related issues in more detail. + + Secure relationship establishment: CONTENT INTERNETWORKING GATEWAYS + must ensure that CONTENT NETWORKS are internetworking only with other + CONTENT NETWORKS as intended. It must be possible to prevent + unauthorized internetworking or spoofing of another CONTENT NETWORK's + identity. + + Secure content transfer: CONTENT INTERNETWORKING GATEWAYS must + support CONTENT NETWORK mechanisms that ensure both the integrity of + CONTENT and the integrity of both DISTRIBUTION and DELIVERY, even + when both ORIGINATING and ENLISTED networks are involved. CONTENT + INTERNETWORKING GATEWAYS must allow for mechanisms to prevent theft + or corruption of CONTENT. + + Secure meta-content transfer: CONTENT INTERNETWORKING GATEWAYS must + support the movement of accurate, reliable, auditable ACCOUNTING + information between CONTENT NETWORKS. CONTENT INTERNETWORKING + GATEWAYS must allow for mechanisms to prevent the diversion or + corruption of ACCOUNTING data and similar meta-content. + +7. Acknowledgements + + The authors acknowledge the contributions and comments of Fred + Douglis (AT&T), Don Gilletti (CacheFlow), Markus Hoffmann (Lucent), + Barron Housel (Cisco), Barbara Liskov (Cisco), John Martin (Network + Appliance), Nalin Mistry (Nortel Networks) Raj Nair (Cisco), Hilarie + Orman (Volera), Doug Potter (Cisco), and Oliver Spatscheck (AT&T). + + + + + + +Day, et al. Informational [Page 15] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + +8. Normative References + + [1] 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. + + [2] Schulzrinne, H., Rao, A. and R. Lanphier, "Real Time Streaming + Protocol", RFC 2326, April 1998. + + [3] Cooper, I., Melve, I. and G. Tomlinson, "Internet Web + Replication and Caching Taxonomy", RFC 3040, June 2000. + +9. Authors' Addresses + + Mark Stuart Day + Cisco Systems + 1414 Massachusetts Avenue + Boxborough, MA 01719 + US + + Phone: +1 978 936 1089 + EMail: mday@alum.mit.edu + + Brad Cain + Storigen Systems + 650 Suffolk Street + Lowell, MA 01854 + US + + Phone: +1 978 323 4454 + EMail: bcain@storigen.com + + Gary Tomlinson + Tomlinson Group + 14324 227th Ave NE + Woodinville, WA 98072 + + Phone: +1 425 503 0881 + EMail: gary@tomlinsongroup.net + + Phil Rzewski + 30 Jennifer Place + San Francisco, CA 94107 + US + + Phone: +1 650 303 3790 + EMail: philrz@yahoo.com + + + + +Day, et al. Informational [Page 16] + +RFC 3466 A Model for Content Internetworking (CDI) February 2003 + + +10. Full Copyright Statement + + Copyright (C) The Internet Society (2003). All Rights Reserved. + + This document and translations of it may be copied and furnished to + others, and derivative works that comment on or otherwise explain it + or assist in its implementation may be prepared, copied, published + and distributed, in whole or in part, without restriction of any + kind, provided that the above copyright notice and this paragraph are + included on all such copies and derivative works. However, this + document itself may not be modified in any way, such as by removing + the copyright notice or references to the Internet Society or other + Internet organizations, except as needed for the purpose of + developing Internet standards in which case the procedures for + copyrights defined in the Internet Standards process must be + followed, or as required to translate it into languages other than + English. + + The limited permissions granted above are perpetual and will not be + revoked by the Internet Society or its successors or assigns. + + This document and the information contained herein is provided on an + "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING + TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING + BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION + HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF + MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. + +Acknowledgement + + Funding for the RFC Editor function is currently provided by the + Internet Society. + + + + + + + + + + + + + + + + + + + +Day, et al. Informational [Page 17] + |