NetInf Protocol Extensions for Cache Control
draft-ahlgren-icnrg-netinf-cache-control-00

Abstract

This document defines NetInf protocol extensions for controlling caching behaviour. This includes bypassing caches, asking to not return data, setting expiration time for objects, and marking objects as non-cacheable.

Status of This Memo

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Copyright Notice

Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved.

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Table of Contents

• 1. Introduction
• 2. Fromorigin extension for NetInf GET
• 2.1. Syntax
• 2.2. Processing
• 3. Nodata extension for NetInf GET
• 3.1. Syntax
• 3.2. Processing
• 4. Expires NDO metadata
• 4.1. Syntax
• 4.2. Processing
• 5. Nocache NDO metadata
• 5.1. Syntax
• 5.2. Processing
• 6. Applications
• 6.1. NetInf ping
• 6.2. Dynamically generated data
• 7. Security Considerations
• 8. Acknowledgements
• 9. Normative References
• Authors' Addresses

1. Introduction

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119. [RFC2119]

Syntax definitions in this memo are specified according to ABNF [RFC5234].

This document describes extensions to the NetInf protocol [I-D.kutscher-icnrg-netinf-proto] for controlling the object caching behaviour from client requests (NetInf GET) and by publishers (NetInf PUBLISH).

The extensions have several uses. For example, they enable a publisher to provide dynamic data that is recomputed at certain intervals. To be useful, the object name must be able to handle dynamic data. The extensions also enable the implementation of a NetInf counterpart to the IP program "ping".

2. Fromorigin extension for NetInf GET

"Fromorigin" is an extension parameter for the NetInf protocol message GET. The latter is defined in Section 5.1 of the NetInf protocol specification [I-D.kutscher-icnrg-netinf-proto]. The purpose of the parameter is to enable a client to ask for an NDO to be served from an origin server, and thus that the NDO is not served from a NetInf cache. The concept of an "origin server" for an NDO needs to be defined more precisely, but the intention is that this is a server that has received and accepted a NetInf PUBLISH message for the NDO with a so called "full put", that is, including the actual NDO content data, or that it is a server that makes the NDO available, for instance by PUBLISH:ing the existence of the NDO to a NetInf name resolution server.

2.1. Syntax

The "fromorigin" parameter MUST be encoded in a json key-value field named "fromorigin" in the "ext" parameter of the GET message. Its data type MUST be boolean with the following interpretation of the values:

true

The client issuing the GET is requesting that the named NDO be served from an origin server (and thus not from a cache).

false

The client issuing the GET is not requesting any special processing. The NDO can be served from a cache or origin server. This is the normal, default, case when the parameter is not present in the GET message.

An example is shown in Figure 1.

    ext = { "fromorigin": true }

    ext = { "nodata": true }

    ext = { "meta": { "expires": 3600 } }

    ext = { "meta": { "nocache": true } }