CDNI J. Seedorf Internet-Draft HFT Stuttgart - Univ. of Applied Sciences Intended status: Standards Track Y. Yang Expires: September 6, 2018 Tongji/Yale K. Ma Ericsson J. Peterson Neustar X. Lin Tongji March 5, 2018 Content Delivery Network Interconnection (CDNI) Request Routing: CDNI Footprint and Capabilities Advertisement using ALTO draft-ietf-alto-cdni-request-routing-alto-01 Abstract The Content Delivery Networks Interconnection (CDNI) WG is defining a set of protocols to inter-connect CDNs, to achieve multiple goals such as extending the reach of a given CDN to areas that are not covered by that particular CDN. One component that is needed to achieve the goal of CDNI is the CDNI Request Routing Footprint & Capabilities Advertisement interface (FCI) [RFC7336]. [RFC8008] has defined precisely the semantics of FCI and provided guidelines on the FCI protocol, but the exact protocol is explicitly outside the scope of that document. In this document, we define an FCI protocol using the Application-Layer Traffic Optimization (ALTO) protocol. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months 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." This Internet-Draft will expire on September 6, 2018. Seedorf, et al. Expires September 6, 2018 [Page 1] Internet-Draft CDNI FCI using ALTO March 2018 Copyright Notice Copyright (c) 2018 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Background . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1. Semantics of FCI Advertisement . . . . . . . . . . . . . 4 2.2. ALTO Background and Benefits . . . . . . . . . . . . . . 6 3. CDNI FCI Map . . . . . . . . . . . . . . . . . . . . . . . . 8 3.1. Media Type . . . . . . . . . . . . . . . . . . . . . . . 8 3.2. HTTP Method . . . . . . . . . . . . . . . . . . . . . . . 9 3.3. Accept Input Parameters . . . . . . . . . . . . . . . . . 9 3.4. Capabilities . . . . . . . . . . . . . . . . . . . . . . 9 3.5. Uses . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.6. Response . . . . . . . . . . . . . . . . . . . . . . . . 9 3.7. Examples . . . . . . . . . . . . . . . . . . . . . . . . 11 3.7.1. IRD Example . . . . . . . . . . . . . . . . . . . . . 11 3.7.2. Basic Example . . . . . . . . . . . . . . . . . . . . 13 3.7.3. Incremental Updates Example . . . . . . . . . . . . . 14 4. Utilizing Network Map . . . . . . . . . . . . . . . . . . . . 15 4.1. Introduce Footprint Type: altonetworkmap . . . . . . . . 15 4.2. Example . . . . . . . . . . . . . . . . . . . . . . . . . 15 4.2.1. IRD Example . . . . . . . . . . . . . . . . . . . . . 15 4.2.2. ALTO Network Map for CDNI FCI Footprints Example . . 16 4.2.3. ALTO Network Map Footprints in CDNI FCI Map . . . . . 16 5. Filtered CDNI FCI Map . . . . . . . . . . . . . . . . . . . . 17 5.1. Media Type . . . . . . . . . . . . . . . . . . . . . . . 18 5.2. HTTP Method . . . . . . . . . . . . . . . . . . . . . . . 18 5.3. Accept Input Parameters . . . . . . . . . . . . . . . . . 18 5.4. Capabilities . . . . . . . . . . . . . . . . . . . . . . 19 5.5. Uses . . . . . . . . . . . . . . . . . . . . . . . . . . 19 5.6. Response . . . . . . . . . . . . . . . . . . . . . . . . 19 5.7. Examples . . . . . . . . . . . . . . . . . . . . . . . . 19 5.7.1. IRD Example . . . . . . . . . . . . . . . . . . . . . 19 5.7.2. Basic Example . . . . . . . . . . . . . . . . . . . . 20 Seedorf, et al. Expires September 6, 2018 [Page 2] Internet-Draft CDNI FCI using ALTO March 2018 5.7.3. Incremental Updates Example . . . . . . . . . . . . . 21 6. Query Footprint Properties using ALTO Unified Property Service . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 6.1. Representing Footprint Objects as Unified Property Map entities . . . . . . . . . . . . . . . . . . . . . . . . 23 6.1.1. ASN Domain . . . . . . . . . . . . . . . . . . . . . 24 6.1.2. COUNTRYCODE Domain . . . . . . . . . . . . . . . . . 24 6.2. Examples . . . . . . . . . . . . . . . . . . . . . . . . 25 6.2.1. IRD Example . . . . . . . . . . . . . . . . . . . . . 25 6.2.2. Property Map Example . . . . . . . . . . . . . . . . 25 6.2.3. Filtered Property Map Example . . . . . . . . . . . . 26 6.2.4. Incremental Updates Example . . . . . . . . . . . . . 27 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 29 7.1. CDNI Meatadata Footprint Type Registry . . . . . . . . . 29 7.2. ALTO Entity Domain Registry . . . . . . . . . . . . . . . 29 7.3. ALTO CDNI FCI Property Type Registry . . . . . . . . . . 29 8. Security Considerations . . . . . . . . . . . . . . . . . . . 30 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 30 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 30 10.1. Normative References . . . . . . . . . . . . . . . . . . 30 10.2. Informative References . . . . . . . . . . . . . . . . . 31 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 32 1. Introduction Many Network Service Providers (NSPs) are currently considering or have already started to deploy Content Delivery Networks (CDNs) within their networks. As a consequence of this development, there is a need for interconnecting these local CDNs. Content Delivery Networks Interconnection (CDNI) has the goal of standardizing protocols to enable such interconnection of CDNs [RFC6707]. The CDNI problem statement [RFC6707] defines four interfaces to be standardized within the IETF for CDN interconnection: o CDNI Request Routing Interface o CDNI Metadata Interface o CDNI Logging Interface o CDNI Control Interface The main purpose of the CDNI Request Routing Interface is described in [RFC6707] as follows: "The CDNI Request Routing interface enables a Request Routing function in an Upstream CDN to query a Request Routing function in a Downstream CDN to determine if the Downstream CDN is able (and willing) to accept the delegated Content Request. Seedorf, et al. Expires September 6, 2018 [Page 3] Internet-Draft CDNI FCI using ALTO March 2018 It also allows the Downstream CDN to control what should be returned to the User Agent in the redirection message by the upstream Request Routing function." On a high level, the scope of the CDNI Request Routing Interface, therefore, contains two main tasks: o determining if the downstream CDN (dCDN) is willing to accept a delegated content request; o redirecting the content request coming from an upstream CDN (uCDN) to the proper entry point or entity in the downstream CDN. Correspondingly, the request routing interface is broadly divided into two functionalities: o CDNI Footprint & Capabilities Advertisement interface (FCI): the advertisement from a dCDN to a uCDN or a query from a uCDN to a dCDN for the uCDN to decide whether to redirect particular user requests to that dCDN; o CDNI Request Routing Redirection interface (RI): the synchronous operation of actually redirecting a user request. This document focuses solely on CDNI FCI, with a goal to specify a new Application-Layer Traffic Optimization (ALTO) [RFC7285] service called "CDNI FCI Map Service", to transport and update CDNI FCI objects, which are defined in a separate document in [RFC8008]. Throughout this document, we use the terminology for CDNI defined in [RFC6707] and [RFC8008]. 2. Background The design of CDNI FCI transport using ALTO depends on understanding of both FCI semantics and ALTO. Hence, we start with a review of both. 2.1. Semantics of FCI Advertisement The CDNI document on "Footprint and Capabilities Semantics" [RFC8008] defines the semantics for the CDNI FCI. It thus provides guidance on what Footprint and Capabilities mean in a CDNI context and how a protocol solution should in principle look like. The definitions in [RFC8008] depend on [RFC8006]. Here we briefly summarize key related points of [RFC8008] and [RFC8006]. For a detailed discussion, the reader is referred to the RFCs. o Footprint and capabilities are tied together and cannot be interpreted independently from each other. In such cases, i.e. Seedorf, et al. Expires September 6, 2018 [Page 4] Internet-Draft CDNI FCI using ALTO March 2018 where capabilities must be expressed on a per footprint basis, it may be beneficial to combine footprint and capabilities advertisement. [RFC8008] integrates footprint and capabilities with an approach of "capabilities with footprint restrictions". o Given that a large part of Footprint and Capabilities Advertisement will actually happen in contractual agreements, the semantics of CDNI Footprint and Capabilities advertisement refer to answering the following question: what exactly still needs to be advertised by the CDNI FCI? For instance, updates about temporal failures of part of a footprint can be useful information to convey via the CDNI request routing interface. Such information would provide updates on information previously agreed in contracts between the participating CDNs. In other words, the CDNI FCI is a means for a dCDN to provide changes/updates regarding a footprint and/or capabilities it has prior agreed to serve in a contract with a uCDN. Hence, server push and incremental encoding will be necessary techniques. o Multiple types of footprints are defined in [RFC8006]: * List of ISO Country Codes * List of AS numbers * Set of IP-prefixes A "set of IP-prefixes" must be able to contain full IP addresses, i.e., a /32 for IPv4 and a /128 for IPv6, and also IP prefixes with an arbitrary prefix length. There must also be support for multiple IP address versions, i.e., IPv4 and IPv6, in such a footprint. o For all of these mandatory-to-implement footprint types, footprints can be viewed as constraints for delegating requests to a dCDN: A dCDN footprint advertisement tells the uCDN the limitations for delegating a request to the dCDN. For IP prefixes or ASN(s), the footprint signals to the uCDN that it should consider the dCDN a candidate only if the IP address of the request routing source falls within the prefix set (or ASN, respectively). The CDNI specifications do not define how a given uCDN determines what address ranges are in a particular ASN. Similarly, for country codes, a uCDN should only consider the dCDN a candidate if it covers the country of the request routing source. The CDNI specifications do not define how a given uCDN determines the country of the request routing source. Multiple footprint constraints are additive, i.e. the advertisement of Seedorf, et al. Expires September 6, 2018 [Page 5] Internet-Draft CDNI FCI using ALTO March 2018 different types of footprint narrows the dCDN candidacy cumulatively. o The following capabilities are defined as "base" capabilities, i.e. ones that are needed in any case and therefore constitute mandatory capabilities to be supported by the CDNI FCI: * Delivery Protocol (e.g., HTTP vs. RTMP) * Acquisition Protocol (for acquiring content from a uCDN) * Redirection Mode (e.g., DNS Redirection vs. HTTP Redirection as discussed in [RFC7336]) * Capabilities related to CDNI Logging (e.g., supported logging mechanisms) * Capabilities related to CDNI Metadata (e.g., authorization algorithms or support for proprietary vendor metadata) 2.2. ALTO Background and Benefits Application-Layer Traffic Optimization (ALTO) [RFC7285] is an approach for guiding the resource provider selection process in distributed applications that can choose among several candidate resources providers to retrieve a given resource. By conveying network layer (topology) information, an ALTO server can provide important information to "guide" the resource provider selection process in distributed applications. Usually, it is assumed that an ALTO server conveys information these applications cannot measure themselves [RFC5693]. Originally, ALTO was motivated by the huge amount of cross-ISP traffic generated by P2P applications [RFC5693]. Recently, however, ALTO is also being considered for improving the request routing in CDNs [I-D.jenkins-alto-cdn-use-cases]. In this context, it has also been proposed to use ALTO for selecting an entry-point in a downstream NSP's network (see section 3.4 "CDN delivering Over-The- Top of a NSP's network" in [I-D.jenkins-alto-cdn-use-cases]). Also, the CDNI problem statement explicitly mentions ALTO as a candidate protocol for "actual algorithms for selection of CDN or Surrogate by Request-Routing systems" [RFC6707]. The following reasons make ALTO a suitable candidate protocol for downstream CDN selection as part of CDNI request routing and in particular for an FCI protocol: Seedorf, et al. Expires September 6, 2018 [Page 6] Internet-Draft CDNI FCI using ALTO March 2018 o CDN request routing is done at the application layer. ALTO is a protocol specifically designed to improve application layer traffic (and application layer connections among hosts on the Internet) by providing additional information to applications that these applications could not easily retrieve themselves. For CDNI, this is exactly the case: a uCDN wants to improve application layer CDN request routing by using dedicated information (provided by a dCDN) that the uCDN could not easily obtain otherwise. o The semantics of an ALTO network map are an exact match for the needed information to convey a footprint by a downstream CDN, in particular if such a footprint is being expressed by IP-prefix ranges. o Security: ALTO maps can be signed and hence provide inherent integrity protection (see Section 8). o RESTful-Design: The ALTO protocol has undergone extensive revisions in order to provide a RESTful design regarding the client-server interaction specified by the protocol. A CDNI FCI interface based on ALTO would inherit this RESTful design. o Error-handling: The ALTO protocol has undergone extensive revisions in order to provide sophisticated error-handling, in particular regarding unexpected cases. A CDNI FCI interface based on ALTO would inherit this thought-through and mature error- handling. o Filtered network map: The ALTO Map Filtering Service (see [RFC7285] for details) would allow a uCDN to query only for parts of an ALTO map. o Server-initiated Notifications and Incremental Updates: In case the footprint or the capabilities of a downstream CDN change abruptly (i.e. unexpectedly from the perspective of an upstream CDN), server-initiated notifications would enable a dCDN to directly inform an upstream CDN about such changes. Consider the case where - due to failure - part of the footprint of the dCDN is not functioning, i.e. the CDN cannot serve content to such clients with reasonable QoS. Without server-initiated notifications, the uCDN might still use a very recent network and cost map from dCDN, and therefore redirect requests to dCDN which it cannot serve. Similarly, the possibility for incremental updates would enable efficient conveyance of the aforementioned (or similar) status changes by the dCDN to the uCDN. The newest design of ALTO supports server pushed incremental updates [I-D.ietf-alto-incr-update-sse]. Seedorf, et al. Expires September 6, 2018 [Page 7] Internet-Draft CDNI FCI using ALTO March 2018 o Content Availability on Hosts: A dCDN might want to express CDN capabilities in terms of certain content types (e.g. codecs/ formats, or content from certain content providers). The new endpoint property for ALTO would enable a dCDN to make such information available to an upstream CDN. This would enable a uCDN to determine if a given dCDN actually has the capabilities for a given request with respect to the type of content requested. o Resource Availability on Hosts or Links: The capabilities on links (e.g. maximum bandwidth) or caches (e.g. average load) might be useful information for an upstream CDN for optimized downstream CDN selection. For instance, if a uCDN receives a streaming request for content with a certain bitrate, it needs to know if it is likely that a dCDN can fulfill such stringent application-level requirements (i.e. can be expected to have enough consistent bandwidth) before it redirects the request. In general, if ALTO could convey such information via new endpoint properties, it would enable more sophisticated means for downstream CDN selection with ALTO. 3. CDNI FCI Map The ALTO protocol is based on an ALTO Information Service Framework which consists of several services, where all ALTO services are "provided through a common transport protocol, messaging structure and encoding, and transaction model" [RFC7285]. The ALTO protocol specification [RFC7285] defines several such services, e.g. the ALTO map service. This document defines a new ALTO Map Service called "CDNI FCI Map Service" which conveys JSON objects of media type "application/cdni". This media type and JSON object format is defined in [RFC8006] and [RFC8008]; this document specifies how to transport such JSON objects via the ALTO protocol with the ALTO "CDNI FCI Map Service". Given that the "CDNI FCI Map Service" is very similar in structure to the two already defined map services (network maps and cost maps), the specification of CDNI FCI Map below uses the same specification structure for Cost Map specification in Section 11.2.3 of [RFC7285] when specifying cost maps. 3.1. Media Type The media type of the CDNI FCI Map is "application/cdni". Seedorf, et al. Expires September 6, 2018 [Page 8] Internet-Draft CDNI FCI using ALTO March 2018 3.2. HTTP Method A CDNI FCI map resource is requested using the HTTP GET method. 3.3. Accept Input Parameters None. 3.4. Capabilities None. 3.5. Uses The resource ID of the resource based on which the CDNI FCI map will be defined. For example, if a CDNI FCI map depends on a network map, the resource ID of the network map MUST be included in "Uses" field. Please see Section 4. If the CDNI FCI map does not depend on any other resources, "Uses" field MUST NOT appear. 3.6. Response If a CDNI FCI map does not depend on other resources, the "meta" field of a CDNI FCI map response MUST include the "vtag" field defined in Section 10.3 of [RFC7285], which provides the version tag of the retrieved CDNI FCI map. If a CDNI FCI map response depends on a resource such a network map, it MUST include the "dependent-vtags" field, whose value is a array to indicate the version tag of the resource used, where the resource is specified in "uses" of the IRD. The current defined dependent resource is only network map, and the usage of it is described in Section 4. The data component of an ALTO CDNI FCI map response is named "cdnifci-map", which is a JSON object of type CDNIFCIMapData: Seedorf, et al. Expires September 6, 2018 [Page 9] Internet-Draft CDNI FCI using ALTO March 2018 object { CDNIFCIMapData cdnifci-map; } InfoResourceCDNIFCIMap : ResponseEntityBase; object { CDNIFCIObject capabilities<1..*>; } CDNIFCIMapData object { JSONString capability-type; JSONValue capability-value; CDNIFCIFootprint footprints<0..*>; } CDNIFCIObject; object { JSONString footprint-type; JSONString footprint-value<1..*>; } CDNIFCIFootprint Specifically, a CDNIFCIMapData object is a JSON object, and it includes only one property "capabilities" and whose value is an array of CDNIFCIobject objects. The CDNIFCIObject object may contain an optional list of CDNIFCIFootprint objects. The FCIFootprint object specifies a "footprint-type" which identifies the contents and encoding of the individual footprint entries contained in the associated "footprint-value" array. Please refer to [RFC8006] and [RFC8008] for formal definitions of capabilities and footprints. The ALTO server MUST interpret FCIfootprint objects appearing multiple times as if they appeared only once. Footprint restriction information MAY be specified using multiple different footprint- types. If no footprint restriction list is specified (or an empty list is specified), it MUST be understood that all footprint types are reset to "global" coverage. Note: Further optimization of the footprint object to provide quality information for a given footprint is certainly possible, however, it is not necessary for the basic interconnection of CDNs. The ability to transfer quality information in capabilities advertisements may be desirable and is noted here for completeness, however, the specifics of such mechanisms are outside the scope of this document. Multiple FCIMapData objects with the same capability type are allowed within a given CDNI FCI Map response as long as the capability option footprint-value do not overlap, i.e., a given capability option value MUST NOT show up in multiple FCIMapData objects within a single CDNI FCI Map response. If multiple FCIMapData objects for a given capability type exist, those capability objects MUST have different Seedorf, et al. Expires September 6, 2018 [Page 10] Internet-Draft CDNI FCI using ALTO March 2018 footprint restrictions. Capability objects of a given capability type with identical footprint restrictions MUST be combined into a single capability object. 3.7. Examples 3.7.1. IRD Example GET /directory HTTP/1.1 Host: alto.example.com Accept: application/alto-directory+json,application/alto-error+json { "meta" : { ... }, "resources": { "my-default-network-map": { "uri" : "http://alto.example.com/networkmap", "media-type" : "application/alto-networkmap+json" }, "my-eu-netmap" : { "uri" : "http://alto.example.com/myeunetmap", "media-type" : "application/alto-networkmap+json" }, "my-default-cdnifci-map": { "uri" : "http://alto.example.com/cdnifcimap", "media-type": "application/cdni" }, "my-filtered-cdnifci-map" : { "uri" : "http://alto.example.com/cdnifcimap/filtered", "media-type" : "application/cdni", "accepts" : "application/alto-cdnifcimapfilter+json", "uses" : [ "my-default-cdnifci-map" ] }, "my-cdnifci-map-with-network-map-footprints": { "uri" : "http://alto.example.com/networkcdnifcimap", "media-type" : "application/cdni", "uses" : [ "my-eu-netmap" ] }, "cdnifci-property-map" : { "uri" : "http://alto.example.com/propmap/full/cdnifci", "media-type" : "application/alto-propmap+json", "capabilities" : { "domain-types" : [ "ipv4", "ipv6", "coutrycode", "asn" ], "prop-types" : [ "cdni-fci-capabilities" ] } }, "filtered-cdnifci-property-map" : { "uri" : "http://alto.example.com/propmap/lookup/cdnifci-pid", Seedorf, et al. Expires September 6, 2018 [Page 11] Internet-Draft CDNI FCI using ALTO March 2018 "media-type" : "application/alto-propmap+json", "accpets" : "application/alto-propmapparams+json", "capabilities" : { "domain-types" : [ "ipv4", "ipv6", "coutrycode", "asn" ], "prop-types" : [ "cdni-fci-capabilities", "pid" ] } }, "update-my-cdni-fci-maps" : { "uri": "http:///alto.example.com/updates/cdnifcimaps", "media-type" : "text/event-stream", "accepts" : "application/alto-updatestreamparams+json", "uses" : [ "my-default-network-map", "my-eu-netmap", "my-default-cdnifci-map", "my-filtered-cdnifci-map" "my-cdnifci-map-with-network-map-footprints" ], "capabilities" : { "incremental-change-media-types" : { "my-default-network-map" : "application/json-patch+json", "my-eu-netmap" : "application/json-patch+json", "my-default-cdnifci-map" : "application/merge-patch+json,application/json-patch+json", "my-filtered-cdnifci-map" : "application/merge-patch+jso,application/json-patch+json", "my-cdnifci-map-with-network-map-footprints" : "application/merge-patch+json,application/json-patch+json" } } }, "update-my-props": { "uri" : "http://alto.example.com/updates/properties", "media-type" : "text/event-stream", "uses" : [ "cdnifci-property-map", "filtered-cdnifci-property-map" ], "capabilities" : { "incremental-change-media-types": { "cdnifci-property-map" : "application/merge-patch+json,application/json-patch+json", "filtered-cdnifci-property-map": "application/merge-patch+json,application/json-patch+json" } } } } Seedorf, et al. Expires September 6, 2018 [Page 12] Internet-Draft CDNI FCI using ALTO March 2018 } 3.7.2. Basic Example GET /cdnifcimap HTTP/1.1 Host: alto.example.com Accept: application/cdni,application/alto-error+json HTTP/1.1 200 OK Content-Length: XXX Content-Type: application/cdni { "meta" : { "vtag": { "resource-id": "my-default-cdnifci-map", "tag": "da65eca2eb7a10ce8b059740b0b2e3f8eb1d4785" } }, "cdnifci-map": { "capabilities": [ { "capability-type": "FCI.DeliveryProtocol", "capability-value": { "delivery-protocols": [ "http/1.1" ] }, "footprints": [ ] }, { "capability-type": "FCI.DeliveryProtocol", "capability-value": { "delivery-protocols": [ "https/1.1", "http/1.1" ] }, "footprints": [ ] }, { "capability-type": "FCI.AcquisitionProtocol", "capability-value": { "acquisition-protocols": [ "https/1.1" Seedorf, et al. Expires September 6, 2018 [Page 13] Internet-Draft CDNI FCI using ALTO March 2018 ] }, "footprints": [ ] } ] } } 3.7.3. Incremental Updates Example In this section, we show an uCDN ALTO client's incremental updates request and the dCDN ALTO server's immediate response. POST /updates/cdnifcimaps HTTP/1.1 Host: alto.example.com Accept: text/event-stream,application/alto-error+json Content-Type: application/alto-updatestreamparams+json Content-Length: ### { "add": { "my-cdnifci-stream": { "resource-id": "my-default-cdnifci-map" } } HTTP/1.1 200 OK Connection: keep-alive Content-Type: text/event-stream event: application/alto-updatestreamcontrol+json data: {"control-uri": data: "http://alto.example.com/updates/streams/3141592653589"} event: application/cdni,my-fci-stream data: { ... full CDNI FCI map ... } event: application/merge-patch+json,my-fci-stream data: { data: "meta": { data: "vtag": { data: "tag": "dasdfa10ce8b059740bddsfasd8eb1d47853716" data: } data: }, data: { data: "capability-type": "FCI.DeliveryProtocol", data: "capability-value": { Seedorf, et al. Expires September 6, 2018 [Page 14] Internet-Draft CDNI FCI using ALTO March 2018 data: "delivery-protocols": [ data: "http/1.1" data: ] data: }, data: "footprints": [ data: data: ] data: } data: } event: application/json-patch+json,my-fci-stream data: [ data: { data: "op": "replace", data: "path": "/meta/vtag/tag", data: "value": "a10ce8b059740b0b2e3f8eb1d4785acd42231bfe" data: }, data: { "op": "add", data: "path": "/cdnifci-map/capabilities/0/footprints/-", data: "value": "ipv4:192.0.2.0/24" data: } data: ] 4. Utilizing Network Map 4.1. Introduce Footprint Type: altonetworkmap As an alternative to the explicit definition of a CDNI Footprint Type (e.g., ipv4cidr, ipv6cidr, asn, countrycode), a reference to an ALTO network map can be used to define a FCI footprint. To enable such referencing to ALTO network maps, a new CDNI Footprint Type "altonetworkmap" is defined (see also Section 7.1). All altonetworkmap entries MUST be of type PIDName (as defined in [RFC7285], where PIDName corresponds to a PID in the ALTO network map referenced by the resource ID of the network map listed in "dependent-vtags" field). 4.2. Example 4.2.1. IRD Example Please see Section 3.7.1 Seedorf, et al. Expires September 6, 2018 [Page 15] Internet-Draft CDNI FCI using ALTO March 2018 4.2.2. ALTO Network Map for CDNI FCI Footprints Example GET /networkmap HTTP/1.1 Host: http://alto.example.com/myeunetmap Accept: application/alto-networkmap+json,application/alto-error+json HTTP/1.1 200 OK Content-Length: XXX Content-Type: application/alto-networkmap+json { "meta" : { "vtag": [ {"resource-id": "my-eu-netmap", "tag": "3ee2cb7e8d63d9fab71b9b34cbf764436315542e" } ] }, "network-map" : { "south-france" : { "ipv4" : [ "192.0.2.0/24", "198.51.100.0/25" ] }, "germany" : { "ipv4" : [ "192.0.3.0/24"] } } } 4.2.3. ALTO Network Map Footprints in CDNI FCI Map GET /networkcdnifcimap HTTP/1.1 Host: alto.example.com Accept: application/cdni,application/alto-error+json Seedorf, et al. Expires September 6, 2018 [Page 16] Internet-Draft CDNI FCI using ALTO March 2018 HTTP/1.1 200 OK Content-Length: 618 Content-Type: application/cdni { "meta" : { "dependent-vtags" : [ { "resource-id": "my-eu-netmap", "tag": "3ee2cb7e8d63d9fab71b9b34cbf764436315542e" } ] }, "cdnifci-map": { "capabilities": [ { "capability-type": "FCI.DeliveryProtocol", "capability-value": [ "http/1.1" ] }, { "capability-type": "FCI.DeliveryProtocol", "capability-value": [ "values": [ "https/1.1" ], "footprints": [ { "footprint-type": "altonetworkmap", "footprint-value": [ "germany", "south-france" ] } ] } ] } } 5. Filtered CDNI FCI Map This document defines a new service named "Filtered CDNI FCI Map Service". And a filtered CDNI FCI map is a CDNI FCI map for which an ALTO client may supply additional capabilities to limit the scope of the resulting CDNI FCI map. The relationship between a filtered CDNI FCI map and a CDNI FCI Map is similar to the relationship between a filtered network/cost map and a network/cost map. Seedorf, et al. Expires September 6, 2018 [Page 17] Internet-Draft CDNI FCI using ALTO March 2018 5.1. Media Type Since a filtered CDNI FCI map is still a CDNI FCI map, it uses the media type defined for CDNI FCI maps at Section 3.1. 5.2. HTTP Method A filtered CDNI FCI map is requested using the HTTP POST method. 5.3. Accept Input Parameters The input parameters for a filtered CDNI FCI map are supplied in the entity body of the POST request. This document specifies the input parameters with a data format indicated by the media type "application/alto-cdni-filter", which is a JSON object of type ReqFilteredCDNIFCIMap, where: object { JSONString capability-type; JSONValue capability-value; } CDNIFCICapability; object { CDNIFCICapability cdni-fci-capabilities<0..*>; } ReqFilteredCDNIFCIMap; with fields: capability-type: The same as Base Advertisement Object's capability- type defined in Section 5.1 of [RFC8008]. capability-value: The same as Base Advertisement Object's capability-value defined in Section 5.1 of [RFC8008]. cdni-fci-capabilities: A list of CDNI FCI capabilities defined in Section 5.1 of [RFC8008] for which footprints are to be returned. If a list is empty, the ALTO server MUST interpret it as a request for the full CDNI FCI Map. The ALTO server MUST interpret entries appearing in a list multiple times as if they appeared only once. The ALTO client SHOULD avoid the same entries appearing in "cdni- fci-capabilities" multiple times. If the "cdni-fci-capabilities" field is not present, the ALTO server MUST interpret it as a request for the full CDNI FCI Map. Seedorf, et al. Expires September 6, 2018 [Page 18] Internet-Draft CDNI FCI using ALTO March 2018 5.4. Capabilities None. 5.5. Uses The resource ID of the CDNI FCI map based on which the filtering is performed. 5.6. Response The format is the same as an unfiltered CDNI FCI map. See Section 3.6 for the format. The returned CDNI FCI map MUST contain only CDNI FCI objects whose CDNI capability object is the superset of one of CDNI capability object in "cdni-fci-capabilities". Specifically, that a CDNI capability object A is the superset of another CDNI capability object B means that these two CDNI capability objects have the same capability type and mandatory properties in capability value of A MUST include mandatory properties in capability value of B semantically. For example, if a CDNI FCI capability in "cdni-fci- capabilities" is Delivery Protocol capability object with "http/1.1" in its field "delivery-protocols" and the original full CDNI FCI map has two CDNI FCI objects whose capabilities are Delivery Protocol capability objects with ["http/1.1"] and ["http/1.1", "https/1.1"] in their field "delivery-protocols" respectively, both of these two CDNI FCI objects MUST be returned. If the input parameters contain a CDNI capability object that is not currently defined, the ALTO server MUST behave as if the CDNI capability object did not appear in the input parameters. The version tag included in the "vtag" field of the response MUST correspond to the full CDNI FCI map resource from which the filtered CDNI FCI map is provided. This ensures that a single, canonical version tag is used independently of any filtering that is requested by an ALTO client. 5.7. Examples 5.7.1. IRD Example Please see Section 3.7.1 Seedorf, et al. Expires September 6, 2018 [Page 19] Internet-Draft CDNI FCI using ALTO March 2018 5.7.2. Basic Example This example is filtering the full CDNI FCI map example in Section 3.7.2. POST /cdnifcimap/filtered HTTP/1.1 HOST: alto.example.com Content-Type: application/cdnifilter+json Accept: application/cdni { "cdni-fci-capabilities": [ { "capability-type": "FCI.DeliveryProtocol", "capability-value": { "delivery-protocols": [ "http/1.1" ] } } ] } Seedorf, et al. Expires September 6, 2018 [Page 20] Internet-Draft CDNI FCI using ALTO March 2018 HTTP/1.1 200 OK Content-Length: XXX Content-Type: application/cdni { "meta" : { "vtag": { "resource-id": "my-default-cdnifci-map", "tag": "da65eca2eb7a10ce8b059740b0b2e3f8eb1d4785" } }, "cdnifci-map": { "capabilities": [ { "capability-type": "FCI.DeliveryProtocol", "capability-value": { "delivery-protocols": [ "http/1.1" ] }, "footprints": [ ] }, { "capability-type": "FCI.DeliveryProtocol", "capability-value": { "delivery-protocols": [ "https/1.1", "http/1.1" ] }, "footprints": [ ] } ] } } 5.7.3. Incremental Updates Example POST /updates/cdnifcimaps HTTP/1.1 Host: fcialtoupdate.example.com Accept: text/event-stream,application/alto-error+json Content-Type: application/alto-updatestreamparams+json Content-Length: ### { "add": { Seedorf, et al. Expires September 6, 2018 [Page 21] Internet-Draft CDNI FCI using ALTO March 2018 "my-fci-stream": { "resource-id": "my-filtered-cdnifci-map", "input": { "cdni-fci-capabilities": [ { "capability-type": "FCI.DeliveryProtocol", "capability-value": { "delivery-protocols": [ "http/1.1" ] } } ] } } } } HTTP/1.1 200 OK Connection: keep-alive Content-Type: text/event-stream event: application/alto-updatestreamcontrol+json data: {"control-uri": data: "http://alto.example.com/updates/streams/3141592653590"} event: application/cdni,my-fci-stream data: { ... full filtered CDNI FCI map ... } event: application/merge-patch+json,my-fci-stream data: { data: "meta": { data: "vtag": { data: "tag": "dasdfa10ce8b059740bddsfasd8eb1d47853716" data: } data: }, data: { data: "capability-type": "FCI.DeliveryProtocol", data: "capability-value": { data: "delivery-protocols": [ data: "http/1.1" data: ] data: }, data: "footprints": [ data: data: ] data: } Seedorf, et al. Expires September 6, 2018 [Page 22] Internet-Draft CDNI FCI using ALTO March 2018 data: } event: application/json-patch+json,my-fci-stream data: [ data: { data: "op": "replace", data: "path": "/meta/vtag/tag", data: "value": "a10ce8b059740b0b2e3f8eb1d4785acd42231bfe" data: }, data: { "op": "add", data: "path": "/cdnifci-map/capabilities/0/footprints/-", data: "value": "ipv4:192.0.2.0/24" data: } data: ] 6. Query Footprint Properties using ALTO Unified Property Service In this section, we describe how ALTO clients look up properties for individual footprints. Our design decision here is to use ALTO unified property map service to query footprint properties because we do not want to introduce extra complexity and ALTO unified property map defined in [I-D.ietf-alto-unified-props-new] already meets the requirement. A footprint is a group of entities, and CDNI capabilities can be regarded as properties of a footprint. Unified property map is used to provide properties for collections of entities such as CIDRs or PIDs. So every footprint can be presented as a set of entities, and we will describe it in details in Section 6.1. In addition, two resource types Property Maps and Filtered Property Maps are already well-defined in [I-D.ietf-alto-unified-props-new]. A unified property map that includes "cdni-fci-capabilities" property registered in Section 7 builds the inverted index of a CDNI FCI map. The building process consists of two steps: firstly, each footprint object is represented as a set of unified property map entities in a domain; secondly, each unified property map entity is mapped into a list of property objects including CDNI capabilities. 6.1. Representing Footprint Objects as Unified Property Map entities A footprint object has two properties: footprint-type and footprint- value. A footprint-value is an array of footprint values conforming to the specification associated with the registered footprint type ("ipv4cidr", "ipv6cidr", "asn", and "countrycode"). Since each unified property map entity has a unique address and each pair of footprint-type and a footprint value determines a group of unique addresses, a footprint object can be represented as a set of entities according to their different footprint-type and footprint values. Seedorf, et al. Expires September 6, 2018 [Page 23] Internet-Draft CDNI FCI using ALTO March 2018 However, [I-D.ietf-alto-unified-props-new] only defines IPv4 Domain and IPv6 Domain which represent footprint-type "ipv4cidr" and "ipv6cidr" respectively. To represent footprint-type "asn" and "countrycode", this document registers two new domains in Section 7. Here gives an example of representing a footprint object as a set of unified property map entities. {"footprint-type": "ipv4cidr", "footprint-value": ["192.0.2.0/24", "198.51.100.0/24"]} --> "ipv4:192.168.2.0/24", "ipv4:198.51.100.0/24" 6.1.1. ASN Domain This document specifies a new domain in addition to the ones in [I-D.ietf-alto-unified-props-new]. ASN is the abbreviation of Autonomous System Number. 6.1.1.1. Domain Name asn 6.1.1.2. Domain-Specific Entity Addresses The entity address of asn domain is encoded as a string consisting of the characters "as" (in lowercase) followed by the ASN [RFC6793]. 6.1.1.3. Hierarchy and Inheritance There is no hierarchy or inheritance for properties associated with ASN. 6.1.2. COUNTRYCODE Domain This document specifies a new domain in addition to the ones in [I-D.ietf-alto-unified-props-new]. 6.1.2.1. Domain Name countrycode 6.1.2.2. Domain-Specific Entity Addresses The entity address of countrycode domain is encoded as an ISO 3166-1 alpha-2 code [ISO3166-1] in lowercase. Seedorf, et al. Expires September 6, 2018 [Page 24] Internet-Draft CDNI FCI using ALTO March 2018 6.1.2.3. Hierarchy and Inheritance There is no hierarchy or inheritance for properties associated with country codes. 6.2. Examples 6.2.1. IRD Example Please see Section Section 3.7.1 6.2.2. Property Map Example GET /propmap/full/cdnifci HTTP/1.1 HOST: alto.example.com Accept: application/alto-propmap+json,application/alto-error+json Seedorf, et al. Expires September 6, 2018 [Page 25] Internet-Draft CDNI FCI using ALTO March 2018 HTTP/1.1 200 OK Content-Length: ### Content-Type: application/alto-propmap+json { "property-map": { "meta": { "dependent-vtags": [ {"resource-id": "my-default-cdnifci-map", "tag": "7915dc0290c2705481c491a2b4ffbec482b3cf62"} ] }, "countrycode:us": { "cdni-fci-capabilities": [{"capability-type":, "capability-value":}] }, "ipv4:192.0.2.0/24": { "cdni-fci-capabilities": [{"capability-type":, "capability-value":}] }, "ipv4:198.51.100.0/24": { "cdni-fci-capabilities": [{"capability-type":, "capability-value":}] }, "ipv6:2001:db8::/32": { "cdni-fci-capabilities": [{"capability-type":, "capability-value":}] }, "asn:as64496": { "cdni-fci-capabilities": [{"capability-type":, "capability-value":}] } } } 6.2.3. Filtered Property Map Example Seedorf, et al. Expires September 6, 2018 [Page 26] Internet-Draft CDNI FCI using ALTO March 2018 POST /propmap/lookup/cdnifci-pid HTTP/1.1 HOST: alto.example.com Content-Type: application/alto-propmapparams+json Accept: application/alto-propmap+json,application/alto-error+json Content-Length: { "entities": [ "ipv4:192.0.2.0/24", "ipv6:2001:db8::/32" ], "properties": [ "cdni-fci-capabilities", "pid" ] } HTTP/1.1 200 OK Content-Length: ### Content-Type: application/alto-propmap+json { "property-map": { "meta": { "dependent-vtags": [ {"resource-id": "my-default-cdnifci-map", "tag": "7915dc0290c2705481c491a2b4ffbec482b3cf62"}, {"resource-id": "my-default-networkmap", "tag": "7915dc0290c2705481c491a2b4ffbec482b3cf63"} ] }, "ipv4:192.0.2.0/24": { "cdni-fci-capabilities": [{"capability-type":, "capability-value":}], "pid": "pid1" }, "ipv6:2001:db8::/32": { "cdni-fci-capabilities": [{"capability-type":, "capability-value":}], "pid": "pid3" } } } 6.2.4. Incremental Updates Example POST /updates/properties HTTP/1.1 Host: alto.example.com Accept: text/event-stream,application/alto-error+json Content-Type: application/alto-updatestreamparams+json Content-Length: ### Seedorf, et al. Expires September 6, 2018 [Page 27] Internet-Draft CDNI FCI using ALTO March 2018 { "add": { "property-map-including-capability-property": { "resource-id": "filtered-cdnifci-property-map", "input": { "properties": ["cdni-fci-capabilities", "pid"], "entities": [ "ipv4:192.0.2.0/24", "ipv6:2001:db8::/32" ] } } } HTTP/1.1 200 OK Connection: keep-alive Content-Type: text/event-stream event: application/alto-updatestreamcontrol+json data: {"control-uri": data: "http://alto.example.com/updates/streams/1414213562373"} event: application/cdni,my-fci-stream data: { ... full filtered unified property map ... } event: application/merge-patch+json,my-fci-stream data: { data: "property-map": data: { data: "meta": { data: "dependent-vtags": [ data: {"resource-id": "my-default-cdnifci-map", data: "tag": "2beeac8ee23c3dd1e98a73fd30df80ece9fa5627"}, data: {"resource-id": "my-default-networkmap", data: "tag": "7915dc0290c2705481c491a2b4ffbec482b3cf63"} data: ] data: }, data: "ipv4:192.0.2.0/24": data: { data: "cdni-fci-capabilities": data: [{"capability-type":,"capability-value":}] data: } data: } data: } event: application/json-patch+json,my-fci-stream data: {[ data: { data: { "op": "replace", Seedorf, et al. Expires September 6, 2018 [Page 28] Internet-Draft CDNI FCI using ALTO March 2018 data: "path": "/meta/dependent-vtags/0/tag", data: "value": "61b23185a50dc7b334577507e8f00ff8c3b409e4" data: }, data: { "op": "replace", data: "path": "/property-map/ipv4:192.0.2.0~124/", data: "value": "pid5" data: } data: } data: ]} 7. IANA Considerations 7.1. CDNI Meatadata Footprint Type Registry +----------------+--------------------------+-----------------------+ | Footprint Type | Description | Specification | +----------------+--------------------------+-----------------------+ | altonetworkmap | URI of an ALTO Server | RFCthis | | | hosting an ALTO network | | | | map, followed by a list | | | | of PID-names | | +----------------+--------------------------+-----------------------+ Table 1: ALTO Entity Domain [RFC Editor: Please replace RFCthis with the published RFC number for this document.] 7.2. ALTO Entity Domain Registry As proposed in Section 9.2 of [I-D.ietf-alto-unified-props-new], "ALTO Entity Domain Registry" is requested. Besides, two new domain is to be registered, listed in Table 2. +--------------+-------------------------+--------------------------+ | Identifier | Entity Address Encoding | Hierarchy & Inheritance | +--------------+-------------------------+--------------------------+ | asn | See Section 6.1.1.2 | None | | countrycode | See Section 6.1.2.2 | None | +--------------+-------------------------+--------------------------+ Table 2: ALTO Entity Domain 7.3. ALTO CDNI FCI Property Type Registry The "ALTO CDNI FCI Property Type Registry" is required by the ALTO Entity Domain "asn", "countrycode", "ipv4" and "ipv6", listed in Table 3. Seedorf, et al. Expires September 6, 2018 [Page 29] Internet-Draft CDNI FCI using ALTO March 2018 +------------------------+------------------------------------------+ | Identifier | Intended Semantics | +------------------------+------------------------------------------+ | cdni-fci-capabilities | An array of CDNI FCI capability objects | +------------------------+------------------------------------------+ Table 3: ALTO CDNI FCI Property Types 8. Security Considerations One important security consideration is the proper authentication of advertisement information provided by a downstream CDN. The ALTO protocol provides a specification for a signature of ALTO information (see Section 15 of [RFC7285]. ALTO thus provides a proper mechanism for protecting the integrity of FCI information. More Security Considerations will be discussed in a future version of this document. 9. Acknowledgments The authors would like to thank Kevin Ma, Daryl Malas, Matt Caulfield for their timely reviews and invaluable comments. Jan Seedorf is partially supported by the GreenICN project (GreenICN: Architecture and Applications of Green Information Centric Networking), a research project supported jointly by the European Commission under its 7th Framework Program (contract no. 608518) and the National Institute of Information and Communications Technology (NICT) in Japan (contract no. 167). The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the GreenICN project, the European Commission, or NICT. 10. References 10.1. Normative References [RFC5693] Seedorf, J. and E. Burger, "Application-Layer Traffic Optimization (ALTO) Problem Statement", RFC 5693, DOI 10.17487/RFC5693, October 2009, . [RFC6707] Niven-Jenkins, B., Le Faucheur, F., and N. Bitar, "Content Distribution Network Interconnection (CDNI) Problem Statement", RFC 6707, DOI 10.17487/RFC6707, September 2012, . Seedorf, et al. Expires September 6, 2018 [Page 30] Internet-Draft CDNI FCI using ALTO March 2018 [RFC6793] Vohra, Q. and E. Chen, "BGP Support for Four-Octet Autonomous System (AS) Number Space", RFC 6793, DOI 10.17487/RFC6793, December 2012, . [RFC7285] Alimi, R., Ed., Penno, R., Ed., Yang, Y., Ed., Kiesel, S., Previdi, S., Roome, W., Shalunov, S., and R. Woundy, "Application-Layer Traffic Optimization (ALTO) Protocol", RFC 7285, DOI 10.17487/RFC7285, September 2014, . [RFC7336] Peterson, L., Davie, B., and R. van Brandenburg, Ed., "Framework for Content Distribution Network Interconnection (CDNI)", RFC 7336, DOI 10.17487/RFC7336, August 2014, . [RFC8006] Niven-Jenkins, B., Murray, R., Caulfield, M., and K. Ma, "Content Delivery Network Interconnection (CDNI) Metadata", RFC 8006, DOI 10.17487/RFC8006, December 2016, . [RFC8008] Seedorf, J., Peterson, J., Previdi, S., van Brandenburg, R., and K. Ma, "Content Delivery Network Interconnection (CDNI) Request Routing: Footprint and Capabilities Semantics", RFC 8008, DOI 10.17487/RFC8008, December 2016, . [ISO3166-1] The International Organization for Standardization, "Codes for the representation of names of countries and their subdivisions -- Part 1: Country codes", ISO 3166-1:2013, 2013. 10.2. Informative References [I-D.ietf-alto-incr-update-sse] Roome, W. and Y. Yang, "ALTO Incremental Updates Using Server-Sent Events (SSE)", draft-ietf-alto-incr-update- sse-07 (work in progress), July 2017. [I-D.jenkins-alto-cdn-use-cases] Niven-Jenkins, B., Watson, G., Bitar, N., Medved, J., and S. Previdi, "Use Cases for ALTO within CDNs", draft- jenkins-alto-cdn-use-cases-03 (work in progress), June 2012. Seedorf, et al. Expires September 6, 2018 [Page 31] Internet-Draft CDNI FCI using ALTO March 2018 [I-D.ietf-alto-unified-props-new] Roome, W. and Y. Yang, "Extensible Property Maps for the ALTO Protocol", draft-ietf-alto-unified-props-new-00 (work in progress), July 2017. Authors' Addresses Jan Seedorf HFT Stuttgart - Univ. of Applied Sciences Schellingstrasse 24 Stuttgart 70174 Germany Phone: +49-0711-8926-2801 Email: jan.seedorf@hft-stuttgart.de Y.R. Yang Tongji/Yale University 51 Prospect Street New Haven, CT 06511 United States of America Email: yry@cs.yale.edu URI: http://www.cs.yale.edu/~yry/ Kevin J. Ma Ericsson 43 Nagog Park Acton, MA 01720 United States of America Phone: +1-978-844-5100 Email: kevin.j.ma@ericsson.com Jon Peterson NeuStar 1800 Sutter St Suite 570 Concord, CA 94520 United States of America Email: jon.peterson@neustar.biz Seedorf, et al. Expires September 6, 2018 [Page 32] Internet-Draft CDNI FCI using ALTO March 2018 X.S. Lin Tongji University 4800 Cao'an Hwy Shanghai 201804 China Email: x.shawn.lin@gmail.com Seedorf, et al. Expires September 6, 2018 [Page 33]