--- 1/draft-ietf-opes-architecture-01.txt 2006-02-05 00:55:48.000000000 +0100 +++ 2/draft-ietf-opes-architecture-02.txt 2006-02-05 00:55:48.000000000 +0100 @@ -1,27 +1,27 @@ Network Working Group Abbie. Barbir Internet-Draft Nortel Networks -Expires: December 10, 2002 R. Chen +Expires: December 18, 2002 R. Chen AT&T Labs M. Hofmann Bell Labs/Lucent Technologies H. Orman - The Purple Streak Development + Purple Streak Development R. Penno Nortel Networks G. Tomlinson - Cacheflow - June 11, 2002 + The Tomlinson Group + June 19, 2002 An Architecture for Open Pluggable Edge Services (OPES) - draft-ietf-opes-architecture-01 + draft-ietf-opes-architecture-02 Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. 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. @@ -30,97 +30,97 @@ 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." The list of current Internet-Drafts can be accessed at http:// www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. - This Internet-Draft will expire on December 10, 2002. + This Internet-Draft will expire on December 18, 2002. Copyright Notice Copyright (C) The Internet Society (2002). All Rights Reserved. Abstract This memo defines an architecture for a cooperative application service in which a data provider, a data consumer, and zero or more application entities cooperatively realize a data stream service. Table of Contents - 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 2. The Architecture . . . . . . . . . . . . . . . . . . . . . . . 4 - 2.1 OPES Entities . . . . . . . . . . . . . . . . . . . . . . . . 4 - 2.2 OPES Flows . . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 2.3 OPES Rules . . . . . . . . . . . . . . . . . . . . . . . . . . 6 - 2.4 Callout Servers . . . . . . . . . . . . . . . . . . . . . . . 7 - 2.5 Policy Enforcement . . . . . . . . . . . . . . . . . . . . . . 8 - 2.6 Tracing Facility . . . . . . . . . . . . . . . . . . . . . . . 9 - 3. Security and Privacy Considerations . . . . . . . . . . . . . 11 - 3.1 Trust Domains . . . . . . . . . . . . . . . . . . . . . . . . 11 - 3.2 Callout protocol . . . . . . . . . . . . . . . . . . . . . . . 12 - 3.3 Privacy . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 - 3.4 Establishing trust . . . . . . . . . . . . . . . . . . . . . . 12 - 3.5 End-to-end Integrity . . . . . . . . . . . . . . . . . . . . . 13 - 4. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 - References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 15 - A. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 17 - Full Copyright Statement . . . . . . . . . . . . . . . . . . . 18 + 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 + 2. The Architecture . . . . . . . . . . . . . . . . . . . . . . 4 + 2.1 OPES Entities . . . . . . . . . . . . . . . . . . . . . . . 4 + 2.1.1 Data Dispatcher . . . . . . . . . . . . . . . . . . . . . . 5 + 2.2 OPES Flows . . . . . . . . . . . . . . . . . . . . . . . . . 6 + 2.3 OPES Rules . . . . . . . . . . . . . . . . . . . . . . . . . 7 + 2.4 Callout Servers . . . . . . . . . . . . . . . . . . . . . . 8 + 2.5 Tracing Facility . . . . . . . . . . . . . . . . . . . . . . 10 + 3. Security and Privacy Considerations . . . . . . . . . . . . 12 + 3.1 Trust Domains . . . . . . . . . . . . . . . . . . . . . . . 12 + 3.2 Callout protocol . . . . . . . . . . . . . . . . . . . . . . 13 + 3.3 Privacy . . . . . . . . . . . . . . . . . . . . . . . . . . 13 + 3.4 Establishing trust . . . . . . . . . . . . . . . . . . . . . 13 + 3.5 End-to-end Integrity . . . . . . . . . . . . . . . . . . . . 14 + 4. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . 15 + References . . . . . . . . . . . . . . . . . . . . . . . . . 16 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 16 + A. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 18 + Full Copyright Statement . . . . . . . . . . . . . . . . . . 19 1. Introduction When realizing a data stream service between a provider and a consumer, the need may arise to provision the use of other application entities, in addition to the provider and consumer. For example, some party may wish to customize a data stream as a service - to a consumer, e.g., a service might customize the data based on the + to a consumer. The customization step might be based on the customer's geographical locality (e.g., language) or resource availability (e.g., display capabilities). In some cases in may be beneficial to provide a customization service at network location instead of deploying it at either the provider or the consumer host. For certain services performed on end-user behalf this may be the only option of service deployment. In this case, one or more additional application entities may participate in the data stream service. There are many possible provisioning scenarios which - make a data stream service attractive. The reader is referred to [1] - for a description of several scenarios. + make a data stream service attractive. In [1] a description of + several scenarios is provided. - The document presents the architectural components of Open Pluggable + This document presents the architectural components of Open Pluggable Edge Services (OPES) that are needed in order to perform a data stream service. The architecture addresses the IAB considerations described in [2]. These considerations are covered in the various parts of the document, specifically with respect to tracing (Section - 2.6) and security considerations (Section 3). + 2.5) and security considerations (Section 3). The document is organized as follows: Section 2 introduces the OPES architecture. Section 3 discusses security considerations. Section 4 provides a summary of the architecture and the requirements for interoperability. 2. The Architecture The architecture of Open Pluggable Edge Services (OPES) can be described in terms of three interrelated concepts, mainly: o OPES entities: processes operating in the network; o OPES flows: data flows that are cooperatively realized by the OPES entities; and, - o OPES rules: these determine how a given data flow is modified by - an OPES entity. + o OPES rules: these specify when and how to execute OPES + intermediary services. 2.1 OPES Entities An OPES entity is an application that operates on a data flow between a data provider application and a data consumer application. OPES entities can be one of the following: o an OPES service application, which analyzes and possibly transforms messages exchanged between the data provider application and the data consumer application; or, @@ -162,20 +162,61 @@ +-------------+ Figure 1: OPES Logical Implementation --------------------------------------------------------------------- Figure 1 depicts a "minimal" stack for OPES. However, other protocols may be present, depending on the functions that are performed by the application. +2.1.1 Data Dispatcher + + Data dispatchers include a ruleset that can be compiled from several + sources and must resolve into an unambiguous result. The compiled + ruleset enables an OPES processor to determine which service + applications to invoke for which data flow. Accordingly, the data + dispatcher constitutes an enhanced policy enforcement point, where + policy rules are evaluated, service-specific data handlers and state + information is maintained, as depicted in Figure 2. + + --------------------------------------------------------------------- + + +----------+ + | callout | + | server | + +----------+ + || + || + || + || + +--------------------------+ + | +----------+ || | + | | OPES | || | + | | service | || | + | | appl | || | + | +----------+ || | + | +----------------------+ | + OPES flow <---->| | data dispatcher and | |<----> OPES flow + | | policy enforcement | | + | +----------------------+ | + | OPES | + | processor | + +--------------------------+ + + Figure 2: Data Dispatchers + + --------------------------------------------------------------------- + + The architecture allows more than one policy enforcement point to be + present on an OPES flow. + 2.2 OPES Flows An OPES flow is a cooperative undertaking between a data provider application, a data consumer application, zero or more OPES service applications, and zero or more data dispatchers. In order to understand the trust relationships between OPES entities, each is labeled as residing in an administrative domain. Entities associated with a given OPES flow may reside in one or more administrative domains. @@ -201,25 +242,25 @@ | | | | | | | | | | | | | +----------+ +--------+ | | +--------+ +----------+ | | | TCP/IP | | TCP/IP | | | | TCP/IP | | TCP/IP | | | +----------+ +--------+ | | +--------+ +----------+ | | || || || | | || || || | | ============= ================= ============= | | | | | +------------------------------+ +------------------------------+ | <----------------- OPES flow -----------------> | - Figure 2: An OPES flow + Figure 3: An OPES flow --------------------------------------------------------------------- - Figure 2 depicts two data dispatchers that are present in the OPES + Figure 3 depicts two data dispatchers that are present in the OPES flow. However, the architecture allows for zero or more data dispatchers to be present in any flow. 2.3 OPES Rules OPES policy regarding services and the data provided to them is determined by a ruleset consisting of OPES rules. The rules consist of a set of conditions and related actions. The ruleset is the superset of all OPES rules on the processor. The OPES ruleset determines which service applications will operate on a data stream. @@ -238,59 +279,63 @@ 2.4 Callout Servers The evaluation of OPES ruleset determines which service applications will operate on a data stream. How the ruleset is evaluated is not the subject of the architecture, except to note that it must result in the same unambiguous result in all implementations. In some cases it may be useful for the OPES processor to distribute the responsibility of service evaluation by communicating with one or more callout servers (cf., [7]). The situation is illustrated in - Figure 3, which shows a data dispatcher communicating with multiple + Figure 4, which shows a data dispatcher communicating with multiple callout servers as it processes an OPES flow. --------------------------------------------------------------------- data callout callout callout dispatcher server server server +----------+ +---------+ +---------+ +---------+ | | | | | | | | | OCP | | OCP | | OCP | ... | OCP | | | | | | | | | +----------+ +---------+ +---------+ +---------+ - | TCP/IP | | TCP/IP | | TCP/IP | | TCP/IP | + | Lower | | Lower | | Lower | | Lower | + | Layer | | Layer | | Layer | | Layer | + |Protocols | |Protocols| |Protocols| |Protocols| + | . | | . | | . | | . | + | . | | . | | . | | . | +----------+ +---------+ +---------+ +---------+ || || || || ||================ || ... || || || || ||============================== || || || ================================================ - Figure 3: An OPES flow with Callout servers + Figure 4: An OPES flow with Callout servers --------------------------------------------------------------------- - In Figure 3, a data dispatcher invokes the services of a callout + In Figure 4, a data dispatcher invokes the services of a callout server by using the OPES callout protocol (OCP). The requirements for the OCP are given in [7]. The OCP is application-agnostic, being unaware of the semantics of the encapsulated application protocol (e.g., HTTP). However, the OCP must incorporate a service aware vectoring capability that parses the data flow according to the ruleset and delivers the data to the OPES service application that can be local or remote. In this model, OPES applications may be executed either on the same processor (or even in the same application environment) with the dispatcher or on a different OPES processor through OCP. The general - interaction situation is depicted in Figure 4, which illustrates the + interaction situation is depicted in Figure 5, which illustrates the positions and interaction of different components of OPES architecture. --------------------------------------------------------------------- +--------------------------+ | +----------+ | | | OPES | | | | service | | +----------------+ | | appl | | | Callout Server | @@ -300,81 +345,33 @@ | | data dispatcher | | | | Service| | | +----------------------+ | | | App2 | | | | HTTP | OCP | | | +--------+ | | +------------| |==========| OCP | | | | |---------+ | | +--------+ | | | TCP/IP | | +----------------+ =========| |=============== OPES Data Flow ==== | +------------+ | +--------------------------+ - Figure 4: Interaction of OPES Entities - - --------------------------------------------------------------------- - -2.5 Policy Enforcement - - Data dispatchers include a ruleset that can be compiled from several - sources and must resolve into an unambiguous result. The compiled - ruleset enables an OPES processor to determain which service - applications to invoke for which data flow. Accordingly, the data - dispatcher constitutes an enhanced Policy Enforcement Point (PEP), - where policy rules are evaluated, service-specific data handlers and - state information are maintained, as depicted in Figure 5. - - --------------------------------------------------------------------- - - +----------+ - | callout | - | server | - +----------+ - || - || - || - || - +---------------------------+ - | +----------+ || | - | | OPES | || | - | | service | || | - | | appl | || | - | +----------+ || | - | +----------------------+ | - OPES flow <---->| | data dispatcher/PEP | | <----> OPES flow - | +----------------------+ | - | OPES | - | processor | - +--------------------------+ - - Figure 5: Data Dispatchers and Policy Enforcement Point + Figure 5: Interaction of OPES Entities --------------------------------------------------------------------- - The architecture allows more than one PEP to be present on an OPES - flow. - -2.6 Tracing Facility - - The architecture makes no requirements as to how an OPES flow is - negotiated, provided that it is consistent with the security policy - (Section 3) of each administrative domain that hosts the OPES - entities that are associated with the flow. +2.5 Tracing Facility - The OPES architecture requires that each data dispatcher provides + The OPES architecture requires that each data dispatcher to provide tracing facilities that allow the appropriate verification of its operation. The OPES architecture requires that tracing be feasible on the OPES flow per OPES processor using in-band annotation. One of those annotations could be a URL with more detailed information on the transformation that occurred to the data on the OPES flow. - Future revisions of the architecture may provide for a tracing - facility to be used for subsequent out-of-band analysis. - Providing the ability for in-band annotation MAY require header extensions on the application protocol that is used (e.g., HTTP). However, the presence of an OPES processor in the data request/ response flow SHALL NOT interfere with the operations of non-OPES aware clients and servers. OPES processors, content server and content consumer MAY use OPES extensions to the base protocol (HTTP), but support of these extensions SHALL NOT be required. OPES processors must obey tracing, reporting and notification requirements set by the center of authority in the trust domain to @@ -527,22 +524,23 @@ [4] Fielding, R., Gettys, J., Mogul, J., Nielsen, H., Masinter, L., Leach, P. and T. Berners-Lee, "Hypertext Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. [5] OPES working group, "OPES Service Authorization and Enforcement Requirements", Internet-Draft TBD, May 2002. [6] OPES working group, "OPES Ruleset Schema", Internet-Draft TBD, May 2002. - [7] OPES working group, "OPES Callout Protocol and Tracing Protocol - Requirements", Internet-Draft TBD, May 2002. + [7] A. Beck et al., "Requirements for OPES Callout Protocols", + Internet-Draft http://www.ietf.org/internet-drafts/draft-ietf- + opes-protocol-reqs-00.txt, May 2002. Authors' Addresses Abbie Barbir Nortel Networks 3500 Carling Avenue Nepean, Ontario K2H 8E9 Canada Phone: +1 613 763 5229 @@ -560,34 +558,34 @@ Bell Labs/Lucent Technologies Room 4F-513 101 Crawfords Corner Road Holmdel, NJ 07733 US Phone: +1 732 332 5983 EMail: hofmann@bell-labs.com Hilarie Orman - The Purple Streak Development + Purple Streak Development EMail: ho@alum.mit.edu Reinaldo Penno Nortel Networks - 2305 Mission College Boulevard - San Jose, CA 95134 + 4555 Great America Parkway + Santa Clara, CA 95054 US EMail: rpenno@nortelnetworks.com Gary Tomlinson - Cacheflow + The Tomlinson Group EMail: gary@tomlinsongroup.net Appendix A. Acknowledgements The authors gratefully acknowledge the contributions of: Marshall T. Rose, John Morris, Oskar Batuner, Mark Baker and Ian Cooper. Full Copyright Statement