idnits 2.17.1 draft-ietf-opes-end-comm-02.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** Looks like you're using RFC 2026 boilerplate. This must be updated to follow RFC 3978/3979, as updated by RFC 4748. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- == No 'Intended status' indicated for this document; assuming Proposed Standard Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** The document seems to lack a both a reference to RFC 2119 and the recommended RFC 2119 boilerplate, even if it appears to use RFC 2119 keywords. RFC 2119 keyword, line 121: '...ntities of an "OPES Domain" MUST be in...' RFC 2119 keyword, line 129: '...n an OPES system MUST be directly addr...' RFC 2119 keyword, line 140: '... MAY not participate in the processi...' RFC 2119 keyword, line 142: '... An OPES domain MUST not be an OPES s...' RFC 2119 keyword, line 151: '... application MUST be able to receive...' (34 more instances...) Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the RFC 3978 Section 5.4 Copyright Line does not match the current year == Line 284 has weird spacing: '...ing and enfor...' == Line 323 has weird spacing: '...be able to tr...' == Line 355 has weird spacing: '...e trace ident...' == Line 364 has weird spacing: '... having the s...' == Line 365 has weird spacing: '... trace entri...' == (4 more instances...) == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'MUST not' in this paragraph: An OPES domain MUST not be an OPES sub-system. An OPES domain MUST require external resources to provide services. An OPES domain is a part of an OPES system belonging to a given operator. OPES domains have no incidence on the structure of an OPES system, but they may influence its organization for different reasons such as security, payment, quality of service, delivery parameters among others. -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (September 18, 2003) is 7524 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Unused Reference: '1' is defined on line 664, but no explicit reference was found in the text == Unused Reference: '4' is defined on line 676, but no explicit reference was found in the text == Unused Reference: '10' is defined on line 702, but no explicit reference was found in the text == Unused Reference: '11' is defined on line 707, but no explicit reference was found in the text ** Downref: Normative reference to an Informational draft: draft-ietf-opes-scenarios (ref. '1') ** Downref: Normative reference to an Informational RFC: RFC 3238 (ref. '2') ** Obsolete normative reference: RFC 2616 (ref. '3') (Obsoleted by RFC 7230, RFC 7231, RFC 7232, RFC 7233, RFC 7234, RFC 7235) -- Possible downref: Non-RFC (?) normative reference: ref. '4' == Outdated reference: A later version (-05) exists of draft-ietf-opes-ocp-core-01 -- Possible downref: Non-RFC (?) normative reference: ref. '6' -- Possible downref: Non-RFC (?) normative reference: ref. '7' -- Possible downref: Non-RFC (?) normative reference: ref. '8' == Outdated reference: A later version (-05) exists of draft-ietf-opes-iab-01 ** Downref: Normative reference to an Informational draft: draft-ietf-opes-iab (ref. '9') Summary: 6 errors (**), 0 flaws (~~), 15 warnings (==), 6 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group A. Barbir 3 Internet-Draft Nortel Networks 4 Expires: March 18, 2004 September 18, 2003 6 OPES processor and end points communications 7 draft-ietf-opes-end-comm-02 9 Status of this Memo 11 This document is an Internet-Draft and is in full conformance with 12 all provisions of Section 10 of RFC2026. 14 Internet-Drafts are working documents of the Internet Engineering 15 Task Force (IETF), its areas, and its working groups. Note that other 16 groups may also distribute working documents as Internet-Drafts. 18 Internet-Drafts are draft documents valid for a maximum of six months 19 and may be updated, replaced, or obsoleted by other documents at any 20 time. It is inappropriate to use Internet-Drafts as reference 21 material or to cite them other than as "work in progress." 23 The list of current Internet-Drafts can be accessed at http:// 24 www.ietf.org/ietf/1id-abstracts.txt. 26 The list of Internet-Draft Shadow Directories can be accessed at 27 http://www.ietf.org/shadow.html. 29 This Internet-Draft will expire on March 18, 2004. 31 Copyright Notice 33 Copyright (C) The Internet Society (2003). All Rights Reserved. 35 Abstract 37 This memo documents tracing requirements for Open Pluggable Edge 38 Services (OPES). 40 Table of Contents 42 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 43 2. OPES Domain and OPES System . . . . . . . . . . . . . . . . 4 44 3. OPES Tracing . . . . . . . . . . . . . . . . . . . . . . . . 6 45 3.1 What is traceable in an OPES Flow? . . . . . . . . . . . . . 6 46 3.2 Requirements for Information Related to Traceable 47 Entities? . . . . . . . . . . . . . . . . . . . . . . . . . 7 48 4. Requirements for OPES processors . . . . . . . . . . . . . . 8 49 5. Requirements for callout servers . . . . . . . . . . . . . . 9 50 6. Privacy considerations . . . . . . . . . . . . . . . . . . . 10 51 6.1 Tracing and Trust Domains . . . . . . . . . . . . . . . . . 10 52 7. How to Support Tracing . . . . . . . . . . . . . . . . . . . 11 53 7.1 Tracing and OPES System Granularity . . . . . . . . . . . . 11 54 7.2 Requirements for In-Band Tracing . . . . . . . . . . . . . . 12 55 7.2.1 Tracing Information Granularity and Persistence levels 56 Requirements . . . . . . . . . . . . . . . . . . . . . . . . 12 57 7.3 Protocol Binding . . . . . . . . . . . . . . . . . . . . . . 13 58 8. Tracing Examples . . . . . . . . . . . . . . . . . . . . . . 14 59 8.1 Single OPES Processor: Detailed Trace . . . . . . . . . . . 14 60 8.2 Single OPES Processor: Partial Trace . . . . . . . . . . . . 15 61 8.3 Multiple OPES Processors: Full Trace . . . . . . . . . . . . 15 62 8.4 Multiple OPES Processors: Partial Trace . . . . . . . . . . 16 63 9. Optional Notification . . . . . . . . . . . . . . . . . . . 18 64 10. IANA considerations . . . . . . . . . . . . . . . . . . . . 20 65 11. Security Considerations . . . . . . . . . . . . . . . . . . 21 66 Normative References . . . . . . . . . . . . . . . . . . . . 22 67 Informative References . . . . . . . . . . . . . . . . . . . 23 68 Author's Address . . . . . . . . . . . . . . . . . . . . . . 23 69 A. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 24 70 Intellectual Property and Copyright Statements . . . . . . . 25 72 1. Introduction 74 The Open Pluggable Edge Services (OPES) architecture [8] enables 75 cooperative application services (OPES services) between a data 76 provider, a data consumer, and zero or more OPES processors. The 77 application services under consideration analyze and possibly 78 transform application-level messages exchanged between the data 79 provider and the data consumer. 81 The execution of such services is governed by a set of rules 82 installed on the OPES processor. The rules enforcement can trigger 83 the execution of service applications local to the OPES processor. 84 Alternatively, the OPES processor can distribute the responsibility 85 of service execution by communicating and collaborating with one or 86 more remote callout servers. As described in [8], an OPES processor 87 communicates with and invokes services on a callout server by using a 88 callout protocol. 90 The work specify the requirements for providing tracing functionality 91 for the OPES architecture [8]. This document specifies tracing 92 mechanisms that the OPES architecture could provide that enable data 93 provider application to detect inappropriate client centric actions 94 by OPES entities. The work focus on developing tracing requirements 95 that can be used to fulfill the notification and Non-Blocking 96 requirements [2]. 98 In the OPES architecture document [8], there is a requirement of 99 relaying tracing information in-band. This work investigates this 100 possibility and discusses possible methods that could be used to 101 detect faulty OPES processors or callout servers by end points in an 102 OPES flow. 104 The document is organized as follows: Section 2 defines OPES Domain 105 and OPES System. Section 3 discusses entities that are traceable in 106 an OPES Flow. Sections 4 and 5 discuss tracing requirements for OPES 107 systems and callout servers. Section 6 focus on Tracing and Trust 108 Domains. Section 7 discusses how to support tracing and provides uses 109 cases. Section 8 provides some examples of traces. Section 9 examines 110 Optional Notification. Section 9 looks into IANA considerations. 111 Section 10 examines security considerations. 113 2. OPES Domain and OPES System 115 This sections clarifies the terms OPES system and OPES Domain [8]. 116 These terms are needed in order to define what is traceable in an 117 OPES Flow [8]. 119 An OPES domain describes the collection of OPES entities that a 120 single provider operates. OPES domains can be based on trust or other 121 operational boundaries. All entities of an "OPES Domain" MUST be in 122 the same trust domain. This would be independent of any specific OPES 123 Flow. 125 An OPES system consists of a limited set of OPES entities, parts of a 126 single or of multiple OPES domains, organized by (or on behalf) of 127 either a data provider application or a data consumer application to 128 perform authorized services on a given application message. Each OPES 129 entity in an OPES system MUST be directly addressable at the IP level 130 by a data consumer application. 132 An OPES system can be formed in a recursive manner. An OPES system 133 can start with either a data provider application or a data consumer 134 application (for a given message). The OPES system then includes any 135 OPES entity trusted by (accepting authority from) an entity that is 136 already in the OPES system. The trust and authority delegation is 137 viewed in the context of the given application message. 139 As implied by the above definition, some OPES entities in the system 140 MAY not participate in the processing of a given message. 142 An OPES domain MUST not be an OPES sub-system. An OPES domain MUST 143 require external resources to provide services. An OPES domain is a 144 part of an OPES system belonging to a given operator. OPES domains 145 have no incidence on the structure of an OPES system, but they may 146 influence its organization for different reasons such as security, 147 payment, quality of service, delivery parameters among others. 149 In Figure 1 an OPES Flow is shown that traverses across various OPES 150 Domains starting from a data provider application. A data consumer 151 application MUST be able to receive tracing information on per 152 message basis that enable it to determine the set of transformations 153 that were performed on the data for a particular OPES Flow. The 154 formation of an OPES Flow can be static or dynamic, meaning that the 155 determination of which OPES Domains will participate in a given OPES 156 Flow (per message basis) can be a function of business arrangements. 158 +------------------------------------------+ 159 | Data Consumer Application | 160 +------------------------------------------+ 161 ^ 162 | 163 +-------------------------------------------+ 164 | OPES System | O | 165 | | | 166 | +-------------------------+ | P | 167 | | OPES Domain | | | 168 | | +---------------+ | | E | 169 | | | OPES Entity | | | | 170 | | +---------------+ | | S | 171 | | . | | | 172 | | . | | | 173 | | +---------------+ | | F | 174 | | |Callout Server | | | | 175 | | +---------------+ | | L | 176 | | | | | 177 | +-------------------------+ | O | 178 | . | | 179 | . | W | 180 | +-------------------------+ | | 181 | | OPES Domain | | | 182 | | +---------------+ | | | 183 | | | OPES Entity | | | | 184 | | +---------------+ | | | 185 | | . | | | 186 | | . | | | 187 | | +---------------+ | | | 188 | | | OPES Entity | | | | 189 | | +---------------+ | | | 190 | +-------------------------+ | | 191 | v | 192 | +-----------------------------------+ | 193 | | Data Provider Application | | 194 | +-----------------------------------+ | 195 | | 196 +-------------------------------------------+ 198 Figure 1: OPES System 200 3. OPES Tracing 202 Before discussing what is traceable in an OPES flow, it is beneficial 203 to define what tracing means. Tracing is defined as the inclusion of 204 necessary information within a message in an OPES flow that could be 205 used to identify the set of transformations or adaptations that have 206 been performed on its content in an OPES System before its delivery 207 to an end point (for example, the data consumer application). 209 o OPES trace: application message information about OPES entities in 210 an OPES System that adapted that message. 212 o OPES tracing: the process of including, manipulating, and 213 interpreting an OPES trace in an OPES System. 215 To emphasize, the above definition means that OPES tracing SHOULD be 216 performed on per message basis. Trace format is dependent on the 217 application protocol that is being adapted by OPES. Data consumer 218 application can use OPES trace to infer the actions that have been 219 performed by the OPES system. The architecture document requires [8] 220 that tracing be supported in-band. 222 In an OPES System the task of providing tracing information, must 223 take into account the following considerations: 225 o Providers may be hesitant to reveal information about their 226 internal network infrastructure. 228 o Within a service provider network, OPES processors may be 229 configured to use non-routable, private IP addresses. 231 o A Data consumer applications would prefer to have a single point 232 of contact regarding the trace information. 234 3.1 What is traceable in an OPES Flow? 236 This section focuses on identifying the traceable entities in an OPES 237 Flow. Tracing information MUST be able to provide a data consumer 238 application with useful information without tracing the exact OPES 239 Processor or callout servers that adapted the data. It is up to the 240 OPES service provider to have maintained appropriate internal 241 detailed traces to find the answer to the data consumer applications 242 inquiry. 244 At the implementation level, for a given trace, an OPES entity 245 involved in handling the corresponding application message is 246 "traceable" or "traced" if information about it appears in that 247 trace. OPES entities have different levels of traceability 248 requirements. Specifically, 250 o An OPES system MUST add its entry to the trace. 252 o An OPES processor SHOULD add its entry to the trace. 254 o An OPES service SHOULD add its entry to the trace. 256 o An OPES entity MAY manage trace information from entities that are 257 under its control. For example, an OPES processor may add or 258 remove callout service entries in order to manage the size of a 259 trace. Other considerations include: 261 * The OPES processor MAY have a fixed configuration that enable 262 it to respond to tracing inquires. 264 * The OPES processor MAY insert a summary of the services that it 265 controls. The summary can be used to respond to tracing 266 inquiries. 268 * The OPES processor MAY package tracing information related to 269 the entities that it control based on the policy of a given 270 OPES System. 272 From an OPES context, a good tracing approach is similar to a trouble 273 ticket ready for submission to a known address. The trace in itself 274 is not necessarily a detailed description of what has happened. It is 275 the responsibility of the operator to resolve the problems. 277 3.2 Requirements for Information Related to Traceable Entities? 279 The requirements for information as related to entities that are 280 traceable in an OPES flow are: 282 o The privacy policy at the time it dealt with the message 284 o Identification of the party responsible for setting and enforcing 285 that policy 287 o Information pointing to a technical contact 289 o Information that identifies, to the technical contact, the OPES 290 processors involved in processing the message. 292 4. Requirements for OPES processors 294 In order to facilitate compliance, the concept of an "OPES system" 295 being traceable, requires that each OPES processor MUST support 296 tracing. Policy can be set that defines which domain has 297 authorization to turn on tracing and its granularity. An OPES 298 provider can have its private policy for trace information, but it 299 MUST support tracing mechanisms and it MUST reveal its policy. 301 The requirements for OPES processors that are applicable to tracing 302 are: 304 o Each OPES processor MUST belong to a single OPES Domain. 306 o Each OPES processor MUST have a Unique Identity in that Domain. 308 o Each OPES processor MUST support tracing, policy can be used to 309 turn tracing on and to determine its granularity. 311 5. Requirements for callout servers 313 In an OPES system, it is the task of an OPES processor to add trace 314 records to application messages. In this case, the callout servers 315 that uses the OCP protocol [5] are not affected by tracing 316 requirements. In order for an OCP protocol to be tracing neutral, an 317 OPES processor in an OPES system MUST be able to meet the following 318 requirements: 320 o Callout services adapt payload regardless of the application 321 protocol in use and leave header adjustment to OPES processor. 323 o OPES processor SHOULD be able to trace it's own invocation and 324 service(s) execution since they understand the application 325 protocol. 327 o Callout servers MAY be able to add their own OPES trace records 328 to application level messages. 330 6. Privacy considerations 332 6.1 Tracing and Trust Domains 334 A trust domain may include several OPES systems and entities. Within 335 a trust domain, there MUST be at least support for one trace entry 336 per OPES system. Entities outside of that system may or may not see 337 any traces, depending on domain policies or configuration. For 338 example, if an OPES system is on the content provider "side", 339 end-users are not guaranteed any traces. If an OPES system is working 340 inside end-user domain, the origin server is not guaranteed any 341 traces related to user requests. 343 7. How to Support Tracing 345 In order to support tracing, the following aspects must be addressed: 347 o There MUST be a System Identifier that identify a domain that is 348 employing an OPES system. 350 o An OPES processor MUST be able to be uniquely identified (MUST 351 have an Identifier) within a system. 353 o An OPES processor SHOULD add its identification to the trace. 355 o An OPES processor SHOULD add to the trace identification of every 356 callout service that received the application message. 358 o If the policy in an OPES system requires an OPES processor to turn 359 tracing on, then the OPES processor MUST add to the trace 360 identification of the "system or entity" it belongs to. "System" 361 ID MUST make it possible to access "system" privacy policy. 363 o An OPES processor MAY group the above information for sequential 364 trace entries having the same "system/entity" ID. In other words, 365 trace entries produced within the same "system or entity" MAY be 366 merged or aggregated into a single less detailed trace entry. 368 o An OPES processor MAY delegate trace management to a callout 369 service within the same "system or entity". 371 7.1 Tracing and OPES System Granularity 373 There are two distinct uses of traces. First, a trace SHOULD enable 374 the "end (content producer or consumer) to detect OPES processor 375 presence within end's trust domain. Such "end" should be able to see 376 a trace entry, but does not need to be able to interpret it beyond 377 identification of the trust domain(s). 379 Second, the domain administrator SHOULD be able to take a trace entry 380 (possibly supplied by an "end? as an opaque string) and interpret it. 381 The administrator must be able to identify OPES processor(s) involved 382 and may be able to identify applied adaptation services along with 383 other message-specific information. That information SHOULD help to 384 explain what OPES entities were involved and the actions that they 385 performed. It may be impractical to provide all the required 386 information in all cases. This document view a trace record as a 387 hint, as opposed to an exhaustive audit. 389 Since the administrators of various trust domains can have various 390 ways of looking into tracing, they MAY require the choice of freedom 391 in what to put in trace records and how to format them. Trace records 392 should be easy to extend beyond basic OPES requirements. Trace 393 management algorithms should treat trace records as opaque data to 394 the extent possible. 396 It is not expected that entities in one trust domain to be able to 397 get all OPES-related feedback from entities in other trust domains. 398 For example, if an end-user suspects that a service was corrupted by 399 a callout service, then, there is no guarantee that the user will be 400 able to identify that service, contact its owner, or debug it, unless 401 the service is within its trust domain. This is no different from the 402 current situation where it is impossible, in general, to know the 403 contact person for an application on an origin server that generates 404 corrupted HTML; and even if the person is known, one should not 405 expect that person to respond to end-user queries. 407 7.2 Requirements for In-Band Tracing 409 The OPES architecture [8] states that traces must be in-band. The 410 support of this design goal is dependent on the specifics of the 411 message application level protocol that is being used in an OPES 412 flow. In-band tracing limits the type of application protocols that 413 OPES can support. The details of what a trace record can convey is 414 also dependent on the choice of the application level protocol. 416 For these reasons, this work documents requirements for application 417 protocols that need to support OPES traces. However, the architecture 418 does not prevent implementers of developing out-of-band protocols and 419 techniques to address the above limitation. 421 7.2.1 Tracing Information Granularity and Persistence levels 422 Requirements 424 In order to be able to trace entities that have acted on an 425 application message in an OPES flow, there may be requirements to 426 keep information that is related to the following: 428 o Message-related information: All data that describes specific 429 actions performed on the message SHOULD be provided with that 430 message, as there is no other way to find message level details at 431 a later stage. 433 o Session related information: Session level data MUST be preserved 434 for the duration of the session. OPES processor is responsible for 435 inserting notifications if session-level information changes. 437 o End-point related data: What profile is activated? Where to get 438 profile details? Where to set preferences? 440 7.3 Protocol Binding 442 The task of adding tracing information is application protocol 443 specific. Separate documents will address HTTP and other protocols. 444 This work documents what tracing information is required and some 445 common tracing elements. 447 8. Tracing Examples 449 This section provides some examples of tracing that could be 450 generated by an OPES System. The examples are based on HTTP [3] and 451 use HTTP extension headers as given in [6]. In [6] trace entries are 452 supplied using HTTP extension message headers. These headers are 453 defined using #list constructs. A valid HTTP message may contain 454 multiple entries of each header. In an OPES Systems, these headers 455 MUST be used to represent the trace entries. 457 In [6], the following HTTP extensions are defined: 459 OPES-System = "OPES-System" ":" #trace-entry 461 OPES-Processor = "OPES-Processor" ":" #trace-entry 463 OPES-Service = "OPES-Service" ":" #trace-entry 465 trace-entry = opes-agent-id *( ";" parameter ) 467 opes-agent-id = absoluteURI 469 8.1 Single OPES Processor: Detailed Trace 471 This example consider the case of an OPES System consisting of a 472 single OPES Processor that is capable of locally performing three 473 OPES services. A data consumer application may receive the following 474 HTTP response message header after OPES adaptations have been 475 applied: 477 HTTP/1.1 200 OK 479 Date: Wed, 15 Nov 1995 06:25:24 GMT 481 Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT 483 Content-type: application/octet-stream 485 OPES-System: http://www.example-opes-systemA.com/ 486 opes?session=ac79a7901549f56 488 OPES-Service: http:// www.example-opes-systemA.com /?sid=123 490 OPES-Service: http:// www.example-opes-systemA.com /cat/?sid=124 492 OPES-Service: http:// www.example-opes-systemA.com /cat/?sid=125 494 In this example, the trace has identified the OPES System and all the 495 OPES services that were performed on the data consumer application 496 original request. 498 8.2 Single OPES Processor: Partial Trace 500 In this example, the OPES System consisting of a two OPES Processor. 501 Each Processor is capable of locally performing many OPES services. A 502 data consumer application may receive the following HTTP response 503 message header after OPES adaptations have been applied: 505 HTTP/1.1 200 OK 507 Date: Wed, 15 Nov 1995 06:25:24 GMT 509 Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT 511 Content-type: application/octet-stream 513 OPES-System: http://www.example-opes-systemA.com/ 514 opes?session=ac79a7901549f56 516 OPES-Service: http:// www.example-opes-systemA.com /?sid=123 518 OPES-Service: http:// www.example-opes-systemA.com /cat/?sid=124 ; 519 Mode = Aggregate 521 In this example, several OPES services may be performed on the 522 request. However, the trace has one entry that fully identifies one 523 service and the other services are identified through a common ID. 524 The OPES system is expected to be able to detail the other services 525 when queried by the data consumer application. 527 8.3 Multiple OPES Processors: Full Trace 529 In this example, the OPES System consisting of a two OPES Processors. 530 Each processor is capable of locally performing two OPES services. A 531 data consumer application may receive the following HTTP response 532 message header after OPES adaptations have been applied: 534 HTTP/1.1 200 OK 536 Date: Wed, 15 Nov 1995 06:25:24 GMT 538 Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT 540 Content-type: application/octet-stream 541 OPES-System: http://www.example-opes-systemA.com/ 542 opes?session=ac79a7901549f56 544 OPES-Service: http:// www.example-opes-Service-Provider1.com /cat/ 545 ?sid=123 547 OPES-Service: http:// www.example-opes-Service-Provider1.com /cat/ 548 ?sid=124 550 OPES-Service: http:// www.example-opes-Service-Provider2.com /xxx/ 551 ?sid=111 553 OPES-Service: http:// www.example-opes-Service-Provider2.com /xxx/ 554 ?sid=112 556 In this example, the trace has identified the OPES System and all the 557 OPES services that were performed on the data consumer application 558 original request. 560 8.4 Multiple OPES Processors: Partial Trace 562 In this example, the OPES System consisting of a two OPES Processors. 563 Each processor is capable of locally performing several OPES 564 services. A data consumer application may receive the following HTTP 565 response message header after OPES adaptations have been applied: 567 HTTP/1.1 200 OK 569 Date: Wed, 15 Nov 1995 06:25:24 GMT 571 Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT 573 Content-type: application/octet-stream 575 OPES-System: http://www.example-opes-systemA.com/ 576 opes?session=ac79a7901549f56 578 OPES-Service: http:// www.example-opes-Service-Provider1.com /cat/ 579 ?sid=123 581 OPES-Service: http:// www.example-opes-Service-Provider1.com /cat/ 582 ?sid=124 ; Mode A 584 OPES-Service: http:// www.example-opes-Service-Provider2.com /xxx/ 585 ?sid=111 587 OPES-Service: http:// www.example-opes-Service-Provider2.com /xxx/ 588 ?sid=112 ; Mode B 590 In this example, several OPES services may be performed on the 591 request. However, the trace partially indicates the services that 592 were performed. The OPES system is expected to be able to detail the 593 other services when queried by the data consumer application. 595 9. Optional Notification 597 This section examines IAB [2] considerations (3.1) and (3.2) 598 regarding notification in an OPES architecture. 600 Notification propagates in opposite direction of tracing and cannot 601 be attached to the application messages that it notifies about. 602 Notification can be done out-band and may require the development of 603 a new protocol. The direction of data flow for tracing and 604 notification are depicted in Figure 2. 606 Notification 607 +----------------------------------------------- 608 | | 609 | V 610 +---------------+ +-------+ +---------------+ 611 | | | | | Data Provider | 612 | Data Consumer | Tracing | OPES |<----->| Application | 613 | Application |<-----------| | +---------------+ 614 +---------------+ +-------+ 615 ^ 616 |OCP 617 | 618 V 619 +---------+ 620 | Callout | 621 | Server | 622 +---------+ 624 Figure 2: Notification Flow 626 In [9] it was argued that Notification is an expensive approach for 627 providing tracing information. However, the current work does not 628 prevent an OPES System from publishing policy and specifications that 629 allow Optional Notification. For example, an OPES System can adopt a 630 mechanism that uses a flag that would allow a data consumer and a 631 data provider application to signal to each other that they are 632 interested to receive an explicit notification if an OPES service is 633 applied to a specific message. The value of this optional flag/field 634 can be a URI that identifies notification method plus parameters. If 635 a processor understands the method, it would be able to further 636 decode the field and send a notification. The specification of the 637 field name and format for an application protocol can be stated in 638 the associated binding document. The details of the notification 639 protocol is beyond the scope of this document. 641 For example, the following HTTP header: 643 OPES-Notify: URI *(pname=pvalue) 645 Or, 647 My-OPES-Notify: foo=bar q=0.5 649 can be used. 651 10. IANA considerations 653 This work does not require any IANA consideration since any actions 654 will be addressed in [6]. 656 11. Security Considerations 658 The security considerations for OPES are documented in [7]. This 659 document is a requirement document for tracing and as such does not 660 develop any new protocols that require security considerations. 662 Normative References 664 [1] A. Barbir et al., "OPES Use Cases and Deployment Scenarios", 665 Internet-Draft http://www.ietf.org/internet-drafts/ 666 draft-ietf-opes-scenarios-01.txt, Auguest 2002. 668 [2] Floyd, S. and L. Daigle, "IAB Architectural and Policy 669 Considerations for Open Pluggable Edge Services", RFC 3238, 670 January 2002. 672 [3] Fielding, R., Gettys, J., Mogul, J., Nielsen, H., Masinter, L., 673 Leach, P. and T. Berners-Lee, "Hypertext Transfer Protocol -- 674 HTTP/1.1", RFC 2616, June 1999. 676 [4] A. Barbir et al., "Policy, Authorization and Enforcement 677 Requirements of OPES", Internet-Draft http://www.ietf.org/ 678 internet-drafts/draft-ietf-opes-authorization-02.txt, February 679 2003. 681 [5] Rousskov, A., "OPES Callout Protocol Core", Internet-Draft 682 http://www.ietf.org/internet-drafts/ 683 draft-ietf-opes-ocp-core-01.txt, August 2003. 685 [6] Rousskov, A., "HTTP adaptation with OPES", Internet-Draft TBD, 686 September 2003. 688 [7] A. Barbir et al., "Security Threats and Risks for Open Pluggable 689 Edge Services", Internet-Draft http://www.ietf.org/ 690 internet-drafts/draft-ietf-opes-threats-02.txt, February 2003. 692 [8] A. Barbir et al., "An Architecture for Open Pluggable Edge 693 Services (OPES)", Internet-Draft http://www.ietf.org/ 694 internet-drafts/draft-ietf-opes-architecture-04, December 2002. 696 [9] A. Barbir et al., "OPES Treatment of IAB Considerations", 697 Internet-Draft http://www.ietf.org/internet-drafts/ 698 draft-ietf-opes-iab-01.txt, February 2004. 700 Informative References 702 [10] Westerinen, A., Schnizlein, J., Strassner, J., Scherling, M., 703 Quinn, B., Herzog, S., Huynh, A., Carlson, M., Perry, J. and S. 704 Waldbusser, "Terminology for Policy-Based Management", RFC 705 3198, November 2001. 707 [11] L. Cranor, et. al, "The Platform for Privacy Preferences 1.0 708 (P3P1.0) Specification", W3C Recommendation 16 http:// 709 www.w3.org/TR/2002/REC-P3P-20020416/ , April 2002. 711 Author's Address 713 Abbie Barbir 714 Nortel Networks 715 3500 Carling Avenue 716 Nepean, Ontario K2H 8E9 717 Canada 719 Phone: +1 613 763 5229 720 EMail: abbieb@nortelnetworks.com 722 Appendix A. Acknowledgements 724 Several people has contributed to this work. Many thanks to: Alex 725 Rousskov, Hilarie Orman, Oscar Batuner, Markus Huffman, Martin 726 Stecher, Marshall Rose and Reinaldo Penno. 728 Intellectual Property Statement 730 The IETF takes no position regarding the validity or scope of any 731 intellectual property or other rights that might be claimed to 732 pertain to the implementation or use of the technology described in 733 this document or the extent to which any license under such rights 734 might or might not be available; neither does it represent that it 735 has made any effort to identify any such rights. Information on the 736 IETF's procedures with respect to rights in standards-track and 737 standards-related documentation can be found in BCP-11. 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