draft-ietf-opes-architecture-04.txt		rfc3835.txt
	Network Working Group A. Barbir		Network Working Group A. Barbir
	Internet-Draft Nortel Networks		Request for Comments: 3835 R. Penno
	Expires: June 11, 2003 R. Chen		Category: Informational Nortel Networks
			R. Chen
	AT&T Labs		AT&T Labs
	M. Hofmann		M. Hofmann
	Bell Labs/Lucent Technologies		Bell Labs/Lucent Technologies
	H. Orman		H. Orman
	Purple Streak Development		Purple Streak Development
	R. Penno		August 2004
	Nortel Networks
	December 11, 2002
	An Architecture for Open Pluggable Edge Services (OPES)		An Architecture for Open Pluggable Edge Services (OPES)
	draft-ietf-opes-architecture-04
	Status of this Memo		Status of this Memo
	This document is an Internet-Draft and is in full conformance with		This memo provides information for the Internet community. It does
	all provisions of Section 10 of RFC2026.		not specify an Internet standard of any kind. Distribution of this
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	Copyright Notice		Copyright Notice
	Copyright (C) The Internet Society (2002). All Rights Reserved.		Copyright (C) The Internet Society (2004).
	Abstract		Abstract
	This memo defines an architecture that enables the creation of an		This memo defines an architecture that enables the creation of an
	application service in which a data provider, a data consumer, and		application service in which a data provider, a data consumer, and
	zero or more application entities cooperatively implement a data		zero or more application entities cooperatively implement a data
	stream service.		stream service.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
	2. The Architecture . . . . . . . . . . . . . . . . . . . . . . 4		2 . The Architecture . . . . . . . . . . . . . . . . . . . . . . . 3
	2.1 OPES Entities . . . . . . . . . . . . . . . . . . . . . . . 4		2.1. OPES Entities. . . . . . . . . . . . . . . . . . . . . . 3
	2.1.1 Data Dispatcher . . . . . . . . . . . . . . . . . . . . . . 5		2.1.1. Data Dispatcher. . . . . . . . . . . . . . . . . 5
	2.2 OPES Flows . . . . . . . . . . . . . . . . . . . . . . . . . 6		2.2. OPES Flows . . . . . . . . . . . . . . . . . . . . . . . 6
	2.3 OPES Rules . . . . . . . . . . . . . . . . . . . . . . . . . 7		2.3. OPES Rules . . . . . . . . . . . . . . . . . . . . . . . 6
	2.4 Callout Servers . . . . . . . . . . . . . . . . . . . . . . 7		2.4. Callout Servers. . . . . . . . . . . . . . . . . . . . . 7
	2.5 Tracing Facility . . . . . . . . . . . . . . . . . . . . . . 9		2.5. Tracing Facility . . . . . . . . . . . . . . . . . . . . 8
	3. Security and Privacy Considerations . . . . . . . . . . . . 11		3. Security and Privacy Considerations . . . . . . . . . . . . . 9
	3.1 Trust Domains . . . . . . . . . . . . . . . . . . . . . . . 11		3.1. Trust Domains. . . . . . . . . . . . . . . . . . . . . . 9
	3.2 Establishing Trust and Service Authorization . . . . . . . . 12		3.2. Establishing Trust and Service Authorization . . . . . . 11
	3.3 Callout protocol . . . . . . . . . . . . . . . . . . . . . . 13		3.3. Callout Protocol . . . . . . . . . . . . . . . . . . . . 11
	3.4 Privacy . . . . . . . . . . . . . . . . . . . . . . . . . . 14		3.4. Privacy. . . . . . . . . . . . . . . . . . . . . . . . . 12
	3.5 End-to-end Integrity . . . . . . . . . . . . . . . . . . . . 14		3.5. End-to-end Integrity . . . . . . . . . . . . . . . . . . 12
	4. IAB Architectural and Policy Considerations for OPES . . . . 15		4. IAB Architectural and Policy Considerations for OPES . . . . . 12
	4.1 IAB consideration (2.1) One-party consent . . . . . . . . . 15		4.1. IAB consideration (2.1) One-party Consent. . . . . . . . 12
	4.2 IAB consideration (2.2) IP-layer communications . . . . . . 15		4.2. IAB consideration (2.2) IP-Layer Communications. . . . . 13
	4.3 IAB consideration (3.1 and 3.2) Notification . . . . . . . . 15		4.3. IAB consideration (3.1 and 3.2) Notification . . . . . . 13
	4.4 IAB consideration (3.3) Non-blocking . . . . . . . . . . . . 15		4.4. IAB consideration (3.3) Non-Blocking . . . . . . . . . . 13
	4.5 IAB consideration (4.1) URI resolution . . . . . . . . . . . 15		4.5. IAB consideration (4.1) URI Resolution . . . . . . . . . 13
	4.6 IAB consideration (4.2) Reference validity . . . . . . . . . 16		4.6. IAB consideration (4.2) Reference Validity . . . . . . . 13
	4.7 IAB consideration (4.3) Application addressing extensions . 16		4.7. IAB consideration (4.3) Application Addressing
	4.8 IAB consideration (5.1) Privacy . . . . . . . . . . . . . . 16		Extensions . . . . . . . . . . . . . . . . . . . . . . . 14
	5. Security Considerations . . . . . . . . . . . . . . . . . . 17		4.8. IAB consideration (5.1) Privacy. . . . . . . . . . . . . 14
	6. IANA Considerations . . . . . . . . . . . . . . . . . . . . 18		5. Security Considerations . . . . . . . . . . . . . . . . . . . 14
	7. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . 19		6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
	Normative References . . . . . . . . . . . . . . . . . . . . 20		7. Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
	Informative References . . . . . . . . . . . . . . . . . . . 21		8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 21		8.1. Normative References . . . . . . . . . . . . . . . . . . 15
	A. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 23		8.2. Informative References . . . . . . . . . . . . . . . . . 15
	Intellectual Property and Copyright Statements . . . . . . . 24		9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 15
			10. Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 16
			11. Full Copyright Statement . . . . . . . . . . . . . . . . . . . 17
	1. Introduction		1. Introduction
	When supplying a data stream service between a provider and a		When supplying a data stream service between a provider and a
	consumer, the need may arise to provision the use of other		consumer, the need to provision the use of other application
	application entities, in addition to the provider and consumer. For		entities, in addition to the provider and consumer, may arise. For
	example, some party may wish to customize a data stream as a service		example, some party may wish to customize a data stream as a service
	to a consumer. The customization step might be based on the		to a consumer. The customization step might be based on the
	customer's resource availability (e.g., display capabilities).		customer's resource availability (e.g., display capabilities).
	In some cases it may be beneficial to provide a customization service		In some cases it may be beneficial to provide a customization service
	at a network location between the provider and consumer host rather		at a network location between the provider and consumer host rather
	than at one of these endpoints. For certain services performed on		than at one of these endpoints. For certain services performed on
	behalf of the end-user, this may be the only option of service		behalf of the end-user, this may be the only option of service
	deployment. In this case, zero or more additional application		deployment. In this case, zero or more additional application
	entities may participate in the data stream service. There are many		entities may participate in the data stream service. There are many
	possible provisioning scenarios which make a data stream service		possible provisioning scenarios which make a data stream service
	attractive. The OPES Use Cases and Deployment Scenarios [1] document		attractive. The OPES Use Cases and Deployment Scenarios [1] document
	provides examples of OPES services. The document discusses services		provides examples of OPES services. The document discusses services
	that modify requests, services that modify responses and services		that modify requests, services that modify responses, and services
	that create responses. It is recommended that the document on OPES		that create responses. It is recommended that the document on OPES
	Use Cases and Deployment Scenarios [1] be read before reading this		Use Cases and Deployment Scenarios [1] be read before reading this
	document.		document.
	This 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		Edge Services (OPES) that are needed in order to perform a data
	stream service. The architecture addresses the IAB considerations		stream service. The architecture addresses the IAB considerations
	described in [2]. These considerations are covered in various parts		described in [2]. These considerations are covered in various parts
	of the document. Section 2.5 addresses tracing, section 3 addresses		of the document. Section 2.5 addresses tracing; section 3 addresses
	security considerations. In section 4 a summary of IAB		security considerations. Section 4 provides a summary of IAB
	considerations and how the architecture addresses them is provided.		considerations and how the architecture addresses them.
	The document is organized as follows: Section 2 introduces the OPES		The document is organized as follows: Section 2 introduces the OPES
	architecture. Section 3 discusses OPES security and privacy		architecture. Section 3 discusses OPES security and privacy
	considerations. Section 4 addresses IAB considerations for OPES.		considerations. Section 4 addresses IAB considerations for OPES.
	Section 5 discusses security considerations. Section 6 addresses		Section 5 discusses security considerations. Section 6 addresses
	IANA considerations. Section 7 provides a summary of the		IANA considerations. Section 7 provides a summary of the
	architecture and the requirements for interoperability.		architecture and the requirements for interoperability.
	2. The Architecture		2. The Architecture
	The architecture of Open Pluggable Edge Services (OPES) can be		The architecture of Open Pluggable Edge Services (OPES) can be
	described in terms of three interrelated concepts, mainly:		described in terms of three interrelated concepts, mainly:
	o OPES entities: processes operating in the network;		o OPES entities: processes operating in the network;
	o OPES flows: data flows that are cooperatively realized by the		o OPES flows: data flows that are cooperatively realized by the
	OPES entities; and,		OPES entities; and,
	o OPES rules: these specify when and how to execute OPES services.		o OPES rules: these specify when and how to execute OPES services.
	2.1 OPES Entities		2.1. OPES Entities
	An OPES entity is an application that operates on a data flow between		An OPES entity is an application that operates on a data flow between
	a data provider application and a data consumer application. OPES		a data provider application and a data consumer application. OPES
	entities can be:		entities can be:
	o an OPES service application, which analyzes and possibly		o an OPES service application, which analyzes and possibly
	transforms messages exchanged between the data provider		transforms messages exchanged between the data provider
	application and the data consumer application;		application and the data consumer application;
	o a data dispatcher, which invokes an OPES service application based		o a data dispatcher, which invokes an OPES service application based
	on an OPES ruleset and application-specific knowledge.		on an OPES ruleset and application-specific knowledge.
	The cooperative behavior of OPES entities introduces additional		The cooperative behavior of OPES entities introduces additional
	functionality for each data flow provided that it matches the OPES		functionality for each data flow provided that it matches the OPES
	rules. In the network, OPES entities reside inside OPES processors.		rules. In the network, OPES entities reside inside OPES processors.
	In the current work, an OPES processor MUST include a data		In the current work, an OPES processor MUST include a data
	dispatcher. Furthermore, the data provider and data consumer		dispatcher. Furthermore, the data provider and data consumer
	applications are not considered as OPES entities.		applications are not considered as OPES entities.
	skipping to change at page 4, line 37		skipping to change at page 4, line 14
	o a data dispatcher, which invokes an OPES service application based		o a data dispatcher, which invokes an OPES service application based
	on an OPES ruleset and application-specific knowledge.		on an OPES ruleset and application-specific knowledge.
	The cooperative behavior of OPES entities introduces additional		The cooperative behavior of OPES entities introduces additional
	functionality for each data flow provided that it matches the OPES		functionality for each data flow provided that it matches the OPES
	rules. In the network, OPES entities reside inside OPES processors.		rules. In the network, OPES entities reside inside OPES processors.
	In the current work, an OPES processor MUST include a data		In the current work, an OPES processor MUST include a data
	dispatcher. Furthermore, the data provider and data consumer		dispatcher. Furthermore, the data provider and data consumer
	applications are not considered as OPES entities.		applications are not considered as OPES entities.
	In order to provide verifiable system integrity (see section 3.1 on		To provide verifiable system integrity (see section 3.1 on trust
	trust domains below), facilitate deployment of end-to-end encryption		domains below) and to facilitate deployment of end-to-end encryption
	and data integrity control , OPES processors MUST be:		and data integrity control , OPES processors MUST be:
	o explicitly addressable at the IP layer by the end user (data		o explicitly addressable at the IP layer by the end user (data
	consumer application). This requirement does not preclude a chain		consumer application). This requirement does not preclude a chain
	of OPES processors with the first one in the chain explicitly		of OPES processors with the first one in the chain explicitly
	addressed at the IP layer by the end user (data consumer		addressed at the IP layer by the end user (data consumer
	application).		application).
	o consented to by either the data consumer or data provider		o consented to by either the data consumer or data provider
	application. The details of this process is beyond the scope of		application. The details of this process are beyond the scope of
	the current work.		the current work.
	The OPES architecture is largely independent of the protocol that is		The OPES architecture is largely independent of the protocol that is
	used by the data provider application and the data consumer		used by the data provider application and the data consumer
	application to exchange data. However, this document selects HTTP		application to exchange data. However, this document selects HTTP
	[3] as the example for the underlying protocol in OPES flows.		[3] as the example for the underlying protocol in OPES flows.
	2.1.1 Data Dispatcher		2.1.1. Data Dispatcher
	Data dispatchers include a ruleset that can be compiled from several		Data dispatchers include a ruleset that can be compiled from several
	sources and MUST resolve into an unambiguous result. The combined		sources and MUST resolve into an unambiguous result. The combined
	ruleset enables an OPES processor to determine which service		ruleset enables an OPES processor to determine which service
	applications to invoke for which data flow. Accordingly, the data		applications to invoke for which data flow. Accordingly, the data
	dispatcher constitutes an enhanced policy enforcement point, where		dispatcher constitutes an enhanced policy enforcement point, where
	policy rules are evaluated, service-specific data handlers and state		policy rules are evaluated and service-specific data handlers and
	information is maintained, as depicted in Figure 1.		state information are maintained, as depicted in Figure 1.
	+----------+		+----------+
	| callout |		| callout |
	| server |		| server |
	+----------+		+----------+
	||		||
	||		||
	||		||
	||		||
	+--------------------------+		+--------------------------+
	skipping to change at page 6, line 32		skipping to change at page 6, line 5
	| +----------------------+ |		| +----------------------+ |
	| OPES |		| OPES |
	| processor |		| processor |
	+--------------------------+		+--------------------------+
	Figure 1: Data Dispatchers		Figure 1: Data Dispatchers
	The architecture allows for more than one policy enforcement point to		The architecture allows for more than one policy enforcement point to
	be present on an OPES flow.		be present on an OPES flow.
	2.2 OPES Flows		2.2. OPES Flows
	An OPES flow is a cooperative undertaking between a data provider		An OPES flow is a cooperative undertaking between a data provider
	application, a data consumer application, zero or more OPES service		application, a data consumer application, zero or more OPES service
	applications, and one or more data dispatchers.		applications, and one or more data dispatchers.
	Since policies are enforced by data dispatchers, the presence of at		Since policies are enforced by data dispatchers, the presence of at
	least one data dispatcher is required in the OPES flow.		least one data dispatcher is required in the OPES flow.
	data OPES OPES data		data OPES OPES data
	provider processor A processor N consumer		consumer processor A processor N provider
	+-----------+ +-----------+ . +-----------+ +-----------+		+-----------+ +-----------+ . +-----------+ +-----------+
	| data | | OPES | . | OPES | | data |		| data | | OPES | . | OPES | | data |
	| consumer | | service | . | service | | provider |		| consumer | | service | . | service | | provider |
	|application| |application| . |application| |application|		|application| |application| . |application| |application|
	+-----------+ +-----------+ . +-----------+ +-----------+		+-----------+ +-----------+ . +-----------+ +-----------+
	| | | | . | | | |		| | | | . | | | |
	| HTTP | | HTTP | . | HTTP | | HTTP |		| HTTP | | HTTP | . | HTTP | | HTTP |
	| | | | . | | | |		| | | | . | | | |
	+-----------+ +-----------+ . +-----------+ +-----------+		+-----------+ +-----------+ . +-----------+ +-----------+
	skipping to change at page 7, line 30		skipping to change at page 6, line 39
	================ =====.======== ===========		================ =====.======== ===========
	| <----------------- OPES flow -------------------> |		| <----------------- OPES flow -------------------> |
	Figure 2: An OPES flow		Figure 2: An OPES flow
	Figure 2 depicts two data dispatchers that are present in the OPES		Figure 2 depicts two data dispatchers that are present in the OPES
	flow. The architecture allows for one or more data dispatchers to be		flow. The architecture allows for one or more data dispatchers to be
	present in any flow.		present in any flow.
	2.3 OPES Rules		2.3. OPES Rules
	OPES policy regarding services and the data provided to them is		OPES' policy regarding services and the data provided to them is
	determined by a ruleset consisting of OPES rules. The rules consist		determined by a ruleset consisting of OPES rules. The rules consist
	of a set of conditions and related actions. The ruleset is the		of a set of conditions and related actions. The ruleset is the
	superset of all OPES rules on the processor. The OPES ruleset		superset of all OPES rules on the processor. The OPES ruleset
	determines which service applications will operate on a data stream.		determines which service applications will operate on a data stream.
	In this model, all data dispatchers are invoked for all flows.		In this model, all data dispatchers are invoked for all flows.
	In order to ensure predictable behavior, the OPES architecture		In order to ensure predictable behavior, the OPES architecture
	requires the use of a standardized schema for the purpose of defining		requires the use of a standardized schema for the purpose of defining
	and interpreting the ruleset. The OPES architecture does not require		and interpreting the ruleset. The OPES architecture does not require
	a mechanism for configuring a ruleset into a data dispatcher. This		a mechanism for configuring a ruleset into a data dispatcher. This
	is treated as a local matter for each implementation (e.g., through		is treated as a local matter for each implementation (e.g., through
	the use of a text editor, secure upload protocol, and so on), as long		the use of a text editor or a secure upload protocol), as long as
	as such mechanism complies with the requirements set forth in section		such a mechanism complies with the requirements set forth in section
	3.		3.
	2.4 Callout Servers		2.4. Callout Servers
	The evaluation of the OPES ruleset determines which service		The evaluation of the OPES ruleset determines which service
	applications will operate on a data stream. How the ruleset is		applications will operate on a data stream. How the ruleset is
	evaluated is not the subject of the architecture, except to note that		evaluated is not the subject of the architecture, except to note that
	it MUST result in the same unambiguous result in all implementations.		it MUST result in the same unambiguous result in all implementations.
	In some cases it may be useful for the OPES processor to distribute		In some cases it may be useful for the OPES processor to distribute
	the responsibility of service execution by communicating with one or		the responsibility of service execution by communicating with one or
	more callout servers. A data dispatcher invokes the services of a		more callout servers. A data dispatcher invokes the services of a
	callout server by using the OPES callout protocol (OCP). The		callout server by using the OPES callout protocol (OCP). The
	requirements for the OCP are given in [6]. The OCP is application-		requirements for the OCP are given in [5]. The OCP is application-
	agnostic, being unaware of the semantics of the encapsulated		agnostic, being unaware of the semantics of the encapsulated
	application protocol (e.g., HTTP). However, the data dispatcher MUST		application protocol (e.g., HTTP). However, the data dispatcher MUST
	incorporate a service aware vectoring capability that parses the data		incorporate a service aware vectoring capability that parses the data
	flow according to the ruleset and delivers the data to either the		flow according to the ruleset and delivers the data to either the
	local or remote OPES service application.		local or remote OPES service application.
	The general interaction situation is depicted in Figure 3, which		The general interaction situation is depicted in Figure 3, which
	illustrates the positions and interaction of different components of		illustrates the positions and interaction of different components of
	OPES architecture.		OPES architecture.
	skipping to change at page 9, line 33		skipping to change at page 8, line 37
	| +---------+ | +-----------+		| +---------+ | +-----------+
	+--------||-||-------------+		+--------||-||-------------+
	|| ||		|| ||
	+--------+ || || +--------+		+--------+ || || +--------+
	|data |== =========================================|data |		|data |== =========================================|data |
	|producer| |consumer|		|producer| |consumer|
	+--------+ +--------+		+--------+ +--------+
	Figure 3: Interaction of OPES Entities		Figure 3: Interaction of OPES Entities
	2.5 Tracing Facility		2.5. Tracing Facility
	The OPES architecture requires that each data dispatcher provides		The OPES architecture requires that each data dispatcher provides
	tracing facilities that allow the appropriate verification of its		tracing facilities that allow the appropriate verification of its
	operation. The OPES architecture requires that tracing be feasible		operation. The OPES architecture requires that tracing be feasible
	on the OPES flow per OPES processor using in-band annotation. One of		on the OPES flow, per OPES processor, using in-band annotation. One
	those annotations could be a URI with more detailed information on		of those annotations could be a URI with more detailed information on
	the OPES services being executed in the OPES flow.		the OPES services being executed in the OPES flow.
	Providing the ability for in-band annotation MAY require header		Providing the ability for in-band annotation MAY require header
	extensions on the application protocol that is used (e.g., HTTP).		extensions on the application protocol that is used (e.g., HTTP).
	However, the presence of an OPES processor in the data request/		However, the presence of an OPES processor in the data request/
	response flow SHALL NOT interfere with the operations of non-OPES		response flow SHALL NOT interfere with the operations of non-OPES
	aware clients and servers. The support of these extensions to the		aware clients and servers. Non-OPES clients and servers need not
	base protocol HTTP is not required by non-OPES clients and servers.		support these extensions to the base protocol.
	OPES processors MUST obey tracing, reporting and notification		OPES processors MUST obey tracing, reporting, and notification
	requirements set by the center of authority in the trust domain to		requirements set by the center of authority in the trust domain to
	which OPES processor belongs. As part of these requirements OPES		which an OPES processor belongs. As part of these requirements, the
	processor may be instructed to reject or ignore such requirements		OPES processor may be instructed to reject or ignore such
	that originate from other trust domains.		requirements that originate from other trust domains.
	3. Security and Privacy Considerations		3. Security and Privacy Considerations
	Each data flow MUST be secured in accordance with several policies.		Each data flow MUST be secured in accordance with several policies.
	The primary stakeholders are the data consumer and the data provider.		The primary stakeholders are the data consumer and the data provider.
	The secondary stakeholders are the entities to which they may have		The secondary stakeholders are the entities to which they may have
	delegated their trust. The other stakeholders are the owners of the		delegated their trust. The other stakeholders are the owners of the
	callout servers. Any of these parties may be participants in the		callout servers. Any of these parties may be participants in the
	OPES flow.		OPES flow.
	These parties MUST have a model, explicit or implicit, describing		These parties MUST have a model, explicit or implicit, describing
	their trust policy; which of the other parties are trusted to operate		their trust policy, which of the other parties are trusted to operate
	on data, and what security enhancements are required for		on data, and what security enhancements are required for
	communication. The trust might be delegated for all data, or it		communication. The trust might be delegated for all data, or it
	might be restricted to granularity as small as an application data		might be restricted to granularity as small as an application data
	unit.		unit.
	All parties that are involved in enforcing policies MUST communicate		All parties that are involved in enforcing policies MUST communicate
	the policies to the parties that are involved. These parties are		the policies to the parties that are involved. These parties are
	trusted to adhere to the communicated policies.		trusted to adhere to the communicated policies.
	In order to delegate fine-grained trust, the parties MUST convey		In order to delegate fine-grained trust, the parties MUST convey
	policy information by implicit contract, by a setup protocol, by a		policy information by implicit contract, by a setup protocol, by a
	dynamic negotiation protocol, or in-line with application data		dynamic negotiation protocol, or in-line with application data
	headers.		headers.
	3.1 Trust Domains		3.1. Trust Domains
	The delegation of authority starts at either a data consumer or data		The delegation of authority starts at either a data consumer or data
	provider and moves to more distant entities in a "stepwise" fashion.		provider and moves to more distant entities in a "stepwise" fashion.
	Stepwise means A delegates to B and B delegates to C and so forth.		Stepwise means A delegates to B, and B delegates to C, and so forth.
	The entities thus "colored" by the delegation are said to form a		The entities thus "colored" by the delegation are said to form a
	trust domain with respect to the original delegating party. Here,		trust domain with respect to the original delegating party. Here,
	"Colored" means that if the first step in the chain is the data		"Colored" means that if the first step in the chain is the data
	provider, then the stepwise delegation "colors" the chain with that		provider, then the stepwise delegation "colors" the chain with that
	data "provider" color. The only colors that are defined are the data		data "provider" color. The only colors defined are the data
	"provider" and the data "consumer". Delegation of authority		"provider" and the data "consumer". Delegation of authority
	(coloring) propagates from the content producer start of authority or		(coloring) propagates from the content producer start of authority or
	from the content consumer start of authority, that may be different		from the content consumer start of authority, which may be different
	from the end points in the data flow.		from the end points in the data flow.
	Figure 4 illustrates administrative domains and out-of-band rules and		Figure 4 illustrates administrative domains, out-of-band rules, and
	policy distribution.		policy distribution.
	provider administrative domain consumer administrative domain		provider administrative domain consumer administrative domain
	+------------------------------+ +-------------------------------+		+------------------------------+ +-------------------------------+
	| +--------------+ | | +--------------+ |		| +--------------+ | | +--------------+ |
	| |Provider | <- out-of-band rules, -> |Consumer | |		| |Provider | <- out-of-band rules, -> |Consumer | |
	| |Administrative|~~>~~~: policies and ~<~|Administrative| |		| |Administrative|~~>~~~: policies and ~<~|Administrative| |
	| |Authority | : service authorization : |Authority | |		| |Authority | : service authorization : |Authority | |
	| +--------------+ : | | : +--------------+ |		| +--------------+ : | | : +--------------+ |
	| : : | | : : |		| : : | | : : |
	skipping to change at page 12, line 48		skipping to change at page 11, line 5
	An OPES processor may be in several trust domains at any time. There		An OPES processor may be in several trust domains at any time. There
	is no restriction on whether the OPES processors are authorized by		is no restriction on whether the OPES processors are authorized by
	data consumers and/or data providers. The original party has the		data consumers and/or data providers. The original party has the
	option of forbidding or limiting redelegation.		option of forbidding or limiting redelegation.
	An OPES processor MUST have a representation of its trust domain		An OPES processor MUST have a representation of its trust domain
	memberships that it can report in whole or in part for tracing		memberships that it can report in whole or in part for tracing
	purposes. It MUST include the name of the party that delegated each		purposes. It MUST include the name of the party that delegated each
	privilege to it.		privilege to it.
	3.2 Establishing Trust and Service Authorization		3.2. Establishing Trust and Service Authorization
	The OPES processor will have configuration policy specifying what		The OPES processor will have a configuration policy specifying what
	privileges the callout servers have and how they are to be		privileges the callout servers have and how they are to be
	identified. OPES uses standard protocols for authentication and		identified. OPES uses standard protocols for authentication and
	otherwise security communication with callout servers.		other security communication with callout servers.
	An OPES processor will have a trusted method for receiving		An OPES processor will have a trusted method for receiving
	configuration information such as rules for the data dispatcher,		configuration information, such as rules for the data dispatcher,
	trusted callout servers, primary parties that opt-in or opt-out of		trusted callout servers, primary parties that opt-in or opt-out of
	individual services, etc.		individual services, etc.
	Protocol(s) for policy/rule distribution are out of scope for this		Protocol(s) for policy/rule distribution are out of scope for this
	document, but the OPES architecture assumes the existence of such a		document, but the OPES architecture assumes the existence of such a
	mechanism.		mechanism.
	Requirements for authorization mechanism are set in a separate		Requirements for the authorization mechanism are set in a separate
	document.		document [4].
	Certain service requests, positive or negative, may be done in-band		Service requests may be done in-band. For example, a request to
	(for example OPES service bypass request, e.g. User agent can insert		bypass OPES services could be signalled by a user agent using an HTTP
	an HTTP header like "Bypass-OPES"). Such requests MUST be		header string "Bypass-OPES". Such requests MUST be authenticated.
	authenticated. The way OPES entities will honor such requests is		The way OPES entities will honor such requests is subordinate to the
	subordinate to the authorization policies effective at that moment.		authorization policies effective at that moment.
	3.3 Callout protocol		3.3. Callout Protocol
	The determination of whether or not OPES processors will use the		The determination of whether or not OPES processors will use the
	measures that are described in the previous section during their		measures that are described in the previous section during their
	communication with callout servers depends on the details of how the		communication with callout servers depends on the details of how the
	primary parties delegated trust to the OPES processors and the trust		primary parties delegated trust to the OPES processors and the trust
	relationship between the OPES processors and the callout server. If		relationship between the OPES processors and the callout server.
	the OPES processors are in a single administrative domain with strong		Strong authentication, message authentication codes, and encryption
	confidentiality guarantees, then encryption may be optional.		SHOULD be used. If the OPES processors are in a single
	However, it is recommended that for all cases that encryption and		administrative domain with strong confidentiality and integrity
	strong authentication be used.		guarantees, then cryptographic protection is recommended but
			optional.
	If the delegation mechanism names the trusted parties and their		If the delegation mechanism names the trusted parties and their
	privileges in some way that permits authentication, then the OPES		privileges in some way that permits authentication, then the OPES
	processors will be responsible for enforcing the policy and for using		processors will be responsible for enforcing the policy and for using
	authentication as part of that enforcement.		authentication as part of that enforcement.
	The callout servers MUST be aware of the policy governing the		The callout servers MUST be aware of the policy governing the
	communication path. They MUST not, for example, communicate		communication path. They MUST not, for example, communicate
	confidential information to auxiliary servers outside the trust		confidential information to auxiliary servers outside the trust
	domain.		domain.
	A separate security association MUST be used for each channel		A separate security association MUST be used for each channel
	established between an OPES processor and a callout server. The		established between an OPES processor and a callout server. The
	channels MUST be separate for different primary parties.		channels MUST be separate for different primary parties.
	3.4 Privacy		3.4. Privacy
	Some data from data consumers is considered "private" or "sensitive",		Some data from OPES flow endpoints is considered "private" or
	and OPES processors MUST both advise the primary parties of their		"sensitive", and OPES processors MUST advise the primary parties of
	privacy policy and respect the policies of the primary parties. The		their privacy policy and respect the policies of the primary parties.
	privacy information MUST be conveyed on a per-flow basis. This can		The privacy information MUST be conveyed on a per-flow basis. This
	be accomplished by using current available privacy techniques such as		can be accomplished by using current available privacy techniques
	P3P [9] and HTTP privacy capabilities.		such as P3P [7] and HTTP privacy capabilities.
	The callout servers MUST also participate in the handling of private		The callout servers MUST also participate in the handling of private
	data, and they MUST be prepared to announce their own capabilities		data, they MUST be prepared to announce their own capabilities, and
	and to enforce the policy required by the primary parties.		enforce the policy required by the primary parties.
	3.5 End-to-end Integrity		3.5. End-to-End Integrity
	Digital signature techniques can be used to mark data changes in such		Digital signature techniques can be used to mark data changes in such
	a way that a third-party can verify that the changes are or are not		a way that a third-party can verify that the changes are or are not
	consistent with the originating party's policy. This requires an		consistent with the originating party's policy. This requires an
	inline manner of specifying policy and its binding to data, a trace		inline method to specify policy and its binding to data, a trace of
	of changes and the party making the changes, and strong identities		changes and the identity of the party making the changes, and strong
	and authentication methods.		identification and authentication methods.
	Strong end-to-end integrity can fulfill some of the functions		Strong end-to-end integrity can fulfill some of the functions
	required by "tracing".		required by "tracing".
	4. IAB Architectural and Policy Considerations for OPES		4. IAB Architectural and Policy Considerations for OPES
	This section addresses the IAB considerations for OPES [2] and		This section addresses the IAB considerations for OPES [2] and
	summarizes how the architecture addresses them.		summarizes how the architecture addresses them.
	4.1 IAB consideration (2.1) One-party consent		4.1. IAB Consideration (2.1) One-Party Consent
	The IAB recommends that all OPES services are explicitly authorized		The IAB recommends that all OPES services be explicitly authorized by
	by one of the application-layer end-hosts (that is, either the data		one of the application-layer end-hosts (that is, either the data
	consumer application or the data provider application).		consumer application or the data provider application).
	The current work requires that either the data consumer application		The current work requires that either the data consumer application
	or the data provider application consent to OPES services. These		or the data provider application consent to OPES services. These
	requirements have been addressed in sections 2 (section 2.1) and 3.		requirements have been addressed in sections 2 (section 2.1) and 3.
	4.2 IAB consideration (2.2) IP-layer communications		4.2. IAB Consideration (2.2) IP-Layer Communications
	The IAB recommends that OPES processors must be explicitly addressed		The IAB recommends that OPES processors must be explicitly addressed
	at the IP layer by the end user (data consumer application).		at the IP layer by the end user (data consumer application).
	This requirement has been addressed in section 2.1, whereby the		This requirement has been addressed in section 2.1, by the
	architecture requires that OPES processors be addressable at the IP		requirement that OPES processors be addressable at the IP layer by
	layer by the data consumer application.		the data consumer application.
	4.3 IAB consideration (3.1 and 3.2) Notification		4.3. IAB Consideration (3.1 and 3.2) Notification
	The IAB recommends that the OPES architecture incorporates tracing		The IAB recommends that the OPES architecture incorporate tracing
	facilities. Tracing enables data consumer and data provider		facilities. Tracing enables data consumer and data provider
	applications to detect and respond to actions performed by OPES		applications to detect and respond to actions performed by OPES
	processors that are deemed inappropriate to the data consumer or data		processors that are deemed inappropriate to the data consumer or data
	provider applications.		provider applications.
	Section 3.2 of this document discusses the tracing and notification		Section 3.2 of this document discusses the tracing and notification
	facilities that must be supported by OPES services.		facilities that must be supported by OPES services.
	4.4 IAB consideration (3.3) Non-blocking		4.4. IAB Consideration (3.3) Non-Blocking
	The OPES architecture requires the specification of extensions to		The OPES architecture requires the specification of extensions to
	HTTP. These extension will provide the data consumer application to		HTTP. These extensions will allow the data consumer application to
	request a non-OPES version of the content from the data provider		request a non-OPES version of the content from the data provider
	application. These requirements is covered in Section 3.2		application. These requirements are covered in Section 3.2.
	4.5 IAB consideration (4.1) URI resolution		4.5. IAB Consideration (4.1) URI Resolution
	This consideration recommends that OPES documentation must be clear		This consideration recommends that OPES documentation must be clear
	in describing that OPES services as being applied to the result of		in describing OPES services as being applied to the result of URI
	URI resolution, not as URI resolution itself.		resolution, not as URI resolution itself.
	This requirement has been addressed in sections 2.5 and 3.2, whereby		This requirement has been addressed in sections 2.5 and 3.2, by
	the proposed architecture requires OPES entities to document all the		requiring OPES entities to document all the transformations that have
	transformations that have been performed.		been performed.
	4.6 IAB consideration (4.2) Reference validity		4.6. IAB Consideration (4.2) Reference Validity
	This consideration recommends that all proposed services must define		This consideration recommends that all proposed services must define
	their impact on inter- and intra-document reference validity.		their impact on inter- and intra-document reference validity.
	This requirement has been addressed in section 2.5 and throughout the		This requirement has been addressed in section 2.5 and throughout the
	document whereby OPES entities is required to document the performed		document whereby OPES entities are required to document the performed
	transformations.		transformations.
	4.7 IAB consideration (4.3) Application addressing extensions		4.7. IAB Consideration (4.3) Application Addressing Extensions
	This consideration recommends that any OPES services that cannot be		This consideration recommends that any OPES services that cannot be
	achieved while respecting the above two considerations may be		achieved while respecting the above two considerations may be
	reviewed as potential requirements for Internet application		reviewed as potential requirements for Internet application
	addressing architecture extensions, but must not be undertaken as ad		addressing architecture extensions, but must not be undertaken as ad
	hoc fixes.		hoc fixes.
	The current work does not require extensions of the Internet		The current work does not require extensions of the Internet
	application addressing architecture.		application addressing architecture.
	4.8 IAB consideration (5.1) Privacy		4.8. IAB Consideration (5.1) Privacy
	This consideration recommends that the overall OPES framework must		This consideration recommends that the overall OPES framework must
	provide for mechanisms for end users to determine the privacy		provide for mechanisms for end users to determine the privacy
	policies of OPES intermediaries.		policies of OPES intermediaries.
	This consideration has been addressed in section 3.		This consideration has been addressed in section 3.
	5. Security Considerations		5. Security Considerations
	The proposed work has to deal with security from various prospective.		The proposed work has to deal with security from various
	There are security and privacy issues that relate to data consumer		perspectives. There are security and privacy issues that relate to
	application, callout protocol and the OPES flow. In [7] threat		data consumer application, callout protocol, and the OPES flow. In
	analysis of OPES entities are discussed.		[6], there is an analysis of the threats against OPES entities.
	6. IANA Considerations		6. IANA Considerations
	The proposed work will evaluate current protocols for OCP. If the		The proposed work will evaluate current protocols for OCP. If the
	work determines that a new protocol need to be developed, then there		work determines that a new protocol needs to be developed, then there
	may be a need to request new numbers from IANA.		may be a need to request new numbers from IANA.
	7. Summary		7. Summary
	Although the architecture supports a wide range of cooperative		Although the architecture supports a wide range of cooperative
	transformation services, it has few requirements for		transformation services, it has few requirements for
	interoperability.		interoperability.
	The necessary and sufficient elements are specified in the following		The necessary and sufficient elements are specified in the following
	documents:		documents:
	o the OPES ruleset schema [5] which defines the syntax and semantics		o the OPES ruleset schema, which defines the syntax and semantics of
	of the rules interpreted by a data dispatcher; and,		the rules interpreted by a data dispatcher; and,
	o the OPES callout protocol (OCP) [6] which defines the requirements		o the OPES callout protocol (OCP) [5], which defines the
	for the protocol between a data dispatcher and a callout server.		requirements for the protocol between a data dispatcher and a
			callout server.
	Normative References		8. References
	[1] McHenry, S., et. al, "OPES Scenarios and Use Cases",		8.1. Normative References
	Internet-Draft TBD, May 2002.
			[1] Barbir, A., Burger, E., Chen, R., McHenry, S., Orman, H., and R.
			Penno, "Open Pluggable Edge Services (OPES) Use Cases and
			Deployment Scenarios", RFC 3752, April 2004.
	[2] Floyd, S. and L. Daigle, "IAB Architectural and Policy		[2] Floyd, S. and L. Daigle, "IAB Architectural and Policy
	Considerations for Open Pluggable Edge Services", RFC 3238,		Considerations for Open Pluggable Edge Services", RFC 3238,
	January 2002.		January 2002.
	[3] Fielding, R., Gettys, J., Mogul, J., Nielsen, H., Masinter, L.,		[3] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., Masinter, L.,
	Leach, P. and T. Berners-Lee, "Hypertext Transfer Protocol --		Leach, P., and T. Berners-Lee, "Hypertext Transfer Protocol --
	HTTP/1.1", RFC 2616, June 1999.		HTTP/1.1", RFC 2616, June 1999.
	[4] OPES working group, "OPES Service Authorization and Enforcement		[4] Barbir, A., Batuner, O., Beck, A., Chan, T., and H. Orman,
	Requirements", Internet-Draft TBD, May 2002.		"Policy, Authorization, and Enforcement Requirements of the Open
			Pluggable Edge Services (OPES)", RFC 3838, August 2004.
	[5] OPES working group, "OPES Ruleset Schema", Internet-Draft TBD,		[5] Beck, A., Hofmann, M., Orman, H., Penno, R., and A. Terzis,
	May 2002.		"Requirements for Open Pluggable Edge Services (OPES) Callout
			Protocols", RFC 3836, August 2004.
	[6] A. Beck et al., "Requirements for OPES Callout Protocols",		[6] Barbir, A., Batuner, O., Srinivas, B., Hofmann, M., and H.
	Internet-Draft http://www.ietf.org/internet-drafts/		Orman, "Security Threats and Risks for Open Pluggable Edge
	draft-ietf-opes-protocol-reqs-03.txt, December 2002.		Services (OPES)", RFC 3837, August 2004.
	[7] A. Barbir et al., "Security Threats and Risks for Open Pluggable		8.2. Informative References
	Edge Services", Internet-Draft http://www.ietf.org/
	internet-drafts/draft-ietf-opes-threats-00.txt, October 2002.
	Informative References		[7] Cranor, L. et. al, "The Platform for Privacy Preferences 1.0
			(P3P1.0) Specification", W3C Recommendation 16
			http://www.w3.org/TR/2002/REC-P3P-20020416/, April 2002.
	[8] Westerinen, A., Schnizlein, J., Strassner, J., Scherling, M.,		9. Acknowledgements
	Quinn, B., Herzog, S., Huynh, A., Carlson, M., Perry, J. and S.
	Waldbusser, "Terminology for Policy-Based Management", RFC 3198,
	November 2001.
	[9] L. Cranor, et. al, "The Platform for Privacy Preferences 1.0		This document is the product of OPES WG. Oskar Batuner (Independent
	(P3P1.0) Specification", W3C Recommendation 16 http://		consultant) and Andre Beck (Lucent) are additional authors that have
	www.w3.org/TR/2002/REC-P3P-20020416/ , April 2002.		contributed to this document.
	Authors' Addresses		Earlier versions of this work were done by Gary Tomlinson (The
			Tomlinson Group) and Michael Condry (Intel).
			The authors gratefully acknowledge the contributions of: John Morris,
			Mark Baker, Ian Cooper and Marshall T. Rose.
			10. Authors' Addresses
	Abbie Barbir		Abbie Barbir
	Nortel Networks		Nortel Networks
	3500 Carling Avenue		3500 Carling Avenue
	Nepean, Ontario K2H 8E9		Nepean, Ontario K2H 8E9
	Canada		Canada
	Phone: +1 613 763 5229		Phone: +1 613 763 5229
	EMail: abbieb@nortelnetworks.com		EMail: abbieb@nortelnetworks.com
	Robin Chen		Yih-Farn Robin Chen
	AT&T Labs		AT&T Labs - Research
	Room E219, 180 Park Avenue		180 Park Avenue
	Florham Park, NJ 07932		Florham Park, NJ 07932
	US		US
	Phone: +1 973 360 8653		Phone: +1 973 360 8653
	EMail: chen@research.att.com		EMail: chen@research.att.com
	Markus Hofmann		Markus Hofmann
	Bell Labs/Lucent Technologies		Bell Labs/Lucent Technologies
	Room 4F-513		Room 4F-513
	101 Crawfords Corner Road		101 Crawfords Corner Road
	skipping to change at page 22, line 4		skipping to change at page 16, line 37
	Room 4F-513		Room 4F-513
	101 Crawfords Corner Road		101 Crawfords Corner Road
	Holmdel, NJ 07733		Holmdel, NJ 07733
	US		US
	Phone: +1 732 332 5983		Phone: +1 732 332 5983
	EMail: hofmann@bell-labs.com		EMail: hofmann@bell-labs.com
	Hilarie Orman		Hilarie Orman
	Purple Streak Development		Purple Streak Development
	EMail: ho@alum.mit.edu		EMail: ho@alum.mit.edu
	Reinaldo Penno		Reinaldo Penno
	Nortel Networks		Nortel Networks
	2305 Mission College Boulevard		600 Technology Park Drive
	San Jose, CA 95134		Billerica, MA 01821
	US		USA
	Phone:
	EMail: rpenno@nortelnetworks.com		EMail: rpenno@nortelnetworks.com
	Appendix A. Acknowledgements		11. Full Copyright Statement
	This document is the product of OPES WG. Oskar Batuner (Independent
	consultant) and Andre Beck (Lucent) are additional authors that have
	contributed to this current document.
	Earlier versions of this work was done by Gary Tomlinson (The		Copyright (C) The Internet Society (2004). This document is subject
	Tomlinson Group) and Michael Condry (Intel).		to the rights, licenses and restrictions contained in BCP 78, and
			except as set forth therein, the authors retain all their rights.
	The authors gratefully acknowledge the contributions of: John Morris,		This document and the information contained herein are provided on an
	Mark Baker, Ian Cooper and Marshall T. Rose.		"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
			OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
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