Application-Layer Traffic Optimization (ALTO) Cross-Domain Server Discovery
RFC 8686
Document | Type | RFC - Proposed Standard (February 2020; No errata) | |
---|---|---|---|
Authors | Sebastian Kiesel , Martin Stiemerling | ||
Last updated | 2020-03-09 | ||
Replaces | draft-kiesel-alto-xdom-disc | ||
Stream | Internet Engineering Task Force (IETF) | ||
Formats | plain text html xml pdf htmlized (tools) htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication (wg milestone: Nov 2017 - Submit alternative s... ) | |
Document shepherd | Jan Seedorf | ||
Shepherd write-up | Show (last changed 2018-10-29) | ||
IESG | IESG state | RFC 8686 (Proposed Standard) | |
Action Holders |
(None)
|
||
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Mirja Kühlewind | ||
Send notices to | Jan Seedorf <jan.seedorf@hft-stuttgart.de> | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | No IANA Actions |
Internet Engineering Task Force (IETF) S. Kiesel Request for Comments: 8686 University of Stuttgart Category: Standards Track M. Stiemerling ISSN: 2070-1721 H-DA February 2020 Application-Layer Traffic Optimization (ALTO) Cross-Domain Server Discovery Abstract The goal of Application-Layer Traffic Optimization (ALTO) is to provide guidance to applications that have to select one or several hosts from a set of candidates capable of providing a desired resource. ALTO is realized by a client-server protocol. Before an ALTO client can ask for guidance, it needs to discover one or more ALTO servers that can provide suitable guidance. In some deployment scenarios, in particular if the information about the network topology is partitioned and distributed over several ALTO servers, it may be necessary to discover an ALTO server outside of the ALTO client's own network domain, in order to get appropriate guidance. This document details applicable scenarios, itemizes requirements, and specifies a procedure for ALTO cross-domain server discovery. Technically, the procedure specified in this document takes one IP address or prefix and a U-NAPTR Service Parameter (typically, "ALTO:https") as parameters. It performs DNS lookups (for NAPTR resource records in the "in-addr.arpa." or "ip6.arpa." trees) and returns one or more URIs of information resources related to that IP address or prefix. Status of This Memo This is an Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc8686. Copyright Notice Copyright (c) 2020 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 (https://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 1.1. Terminology and Requirements Language 2. ALTO Cross-Domain Server Discovery Procedure: Overview 3. ALTO Cross-Domain Server Discovery Procedure: Specification 3.1. Interface 3.2. Step 1: Prepare Domain Name for Reverse DNS Lookup 3.3. Step 2: Prepare Shortened Domain Names 3.4. Step 3: Perform DNS U-NAPTR Lookups 3.5. Error Handling 4. Using the ALTO Protocol with Cross-Domain Server Discovery 4.1. Network and Cost Map Service 4.2. Map-Filtering Service 4.3. Endpoint Property Service 4.4. Endpoint Cost Service 4.5. Summary and Further Extensions 5. Implementation, Deployment, and Operational Considerations 5.1. Considerations for ALTO Clients 5.2. Considerations for Network Operators 6. Security Considerations 6.1. Integrity of the ALTO Server's URI 6.2. Availability of the ALTO Server Discovery Procedure 6.3. Confidentiality of the ALTO Server's URI 6.4. Privacy for ALTO Clients 7. IANA Considerations 8. References 8.1. Normative References 8.2. Informative References Appendix A. Solution Approaches for Partitioned ALTO Knowledge A.1. Classification of Solution Approaches A.2. Discussion of Solution Approaches A.3. The Need for Cross-Domain ALTO Server Discovery A.4. Our Solution Approach A.5. Relation to the ALTO Requirements Appendix B. Requirements for Cross-Domain Server Discovery B.1. Discovery Client Application Programming Interface B.2. Data Storage and Authority Requirements B.3. Cross-Domain Operations Requirements B.4. Protocol Requirements B.5. Further Requirements Appendix C. ALTO and Tracker-Based Peer-to-Peer Applications C.1. A Generic Tracker-Based Peer-to-Peer Application C.2. Architectural Options for Placing the ALTO Client C.3. Evaluation C.4. Example Acknowledgments Authors' AddressesShow full document text