Internet-Draft ALTO Performance Cost Metrics October 2021
Yang Expires 27 April 2022 [Page]
Workgroup:
ALTO Working Group
Internet-Draft:
draft-yang-alto-transport-analysis-00
Published:
Intended Status:
Standards Track
Expires:
Author:
Y. Yang
Yale University

ALTO Transport Analysis

Abstract

Exposing network information to applications can be a basic function of computer networking. Such network information can be exposed to applications through either the data path or the control path. This informational document conducts a survey and analysis of existing capabilities and performance of protocols transporting network information to applications.

Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119][RFC8174] when, and only when, they appear in all capitals, as shown here.

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 https://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 27 April 2022.

Table of Contents

1. Introduction

Application-Layer Traffic Optimization (ALTO) provides a means for network applications to obtain network status information so that the applications can identify efficient application-layer traffic patterns using the networks. Recently, multiple extensions are proposed to the ALTO base protocol [RFC7285] to extend the ability of ALTO to transport network information to applications. The objective of this document is to put ALTO transport in the general context of transporting network information to applications, and evaluate ALTO and related protocols in their transport capabilities and efficiencies.

2. Transport Designs

There can be a large design space to transport network information to applications. Broadly, the designs can be classified into two types: data path transport and control path transport. An example of data path transport is TCP ECN options, which allows networks to convey network information to applications (i.e., endhosts). In a general data path design, as data packets traverse a network, the network elements update the field(s) of the data packets to provide network information. The recent development of in-network telemetry (INT) focuses on data path transport. This document focuses on TCP options based data path transport.

ALTO base protocol, on the other hand, is a control path design. In a general control path design, the network information is collected by a service and exposed to applications. This document focuses on ALTO transport and 3GPP NEF.

3. Capabilities

3.1. Information Model

The information model includes the following abilities: information availability, information selection, update control, etc.

3.2. Latency

3.3. Encoding Efficiency

4. Security Considerations

There can be substantial security issues when transporting network information to applications.

5. IANA Considerations

This informational document does not have IANA consideration.

6. Acknowledgments

The author thanks many reviewers for their comments.

7. References

7.1. Normative References

[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC2818]
Rescorla, E., "HTTP Over TLS", RFC 2818, DOI 10.17487/RFC2818, , <https://www.rfc-editor.org/info/rfc2818>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/info/rfc8174>.

7.2. Informative References

[Prometheus]
Volz, J. and B. Rabenstein, "Prometheus: A Next-Generation Monitoring System", .
[Prophet]
Gao, K., Zhang, J., and YR. Yang, "Prophet: Fast, Accurate Throughput Prediction with Reactive Flows", ACM/IEEE Transactions on Networking July, .
[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, , <https://www.rfc-editor.org/info/rfc7285>.
[RFC8446]
Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, , <https://www.rfc-editor.org/info/rfc8446>.

Author's Address

Y. Richard Yang
Yale University
51 Prospect St
New Haven, CT 06520
United States of America