Prefix Announcement Protocol¶

The prefix announcement protocol allows registering prefixes using a prefix announcement object. It is an alternative to NFD RIB Management protocol's rib/register verb.

Prefix Announcement object¶

The prefix announcement object is a Data packet that represents an application's intent of registering a prefix toward the application. A Data packet that satisfies the following requirements is a prefix announcement object:

• Name starts with the announced prefix, followed by prefix-announcement constant component, followed by a version component and a segment component as defined in NDN Naming Convention.
• ContentType is "prefix announcement".
• Content contains zero or more TLV elements.

A prefix announcement object, by default, is valid indefinitely. Its validity period can be constrained with ValidityPeriod or FreshnessPeriod element.

• ValidityPeriod gives the absolute time range in which the prefix announcement remains valid. It is ignored if the receiving node does not have a UnixTime clock.
• FreshnessPeriod gives the duration in which the prefix announcement remains valid. The duration begins when a node or program receives the prefix announcement.
• When both ValidityPeriod and FreshnessPeriod are present, the most restricted constraint applies.

Trust model of prefix announcement is to be defined by application.

Command Verbs¶

'announce'¶

This command announces a prefix using a prefix announcement object.
NFD-RIB accepts this command as a Command Interest with the following syntax:

/localhost/nfd/rib/announce/<params-sha256>/<command-interest-components>
/localhop/nfd/rib/announce/<params-sha256>/<command-interest-components>

The Interest's Parameters element carries the prefix announce object.

NFD-RIB converts this command into an equivalent rib/register command. Route origin is set to "prefix announcement" (number 129).
Response is same as rib/register command.

'unannounce'¶

There is no 'unannounce' command. Instead, use rib/unregister command.