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
Prefix Announcement object¶
The prefix announcement object is a Data packet that represents an application's intent of registering a prefix toward itself. A Data packet that satisfies the following requirements is a prefix announcement object:
- Name starts with the announced prefix, followed by a fixed
32=PAkeyword name component, followed by a version component and a segment component as defined by the NDN Naming Conventions. In the current revision of this specification, the segment number MUST be zero.
- ContentType MUST be 5 (prefix announcement).
- Content contains a sequence of TLV elements, including at least an ExpirationPeriod element. Ordering of these TLV elements is insignificant. Unrecognized non-critical TLV elements are permitted and MUST be ignored.
Validity period of a prefix announcement object is given in ExpirationPeriod and ValidityPeriod elements in its Content.
- ExpirationPeriod gives the duration for which the prefix announcement remains valid. The duration begins when a node or program receives the prefix announcement. This element is required.
- 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. This element is optional.
- When both ExpirationPeriod and ValidityPeriod are present, the most restrictive constraint applies.
The trust model of a prefix announcement is to be defined by the application.
Data Name /net/example/32=PA/%FD%01/%00%00 MetaInfo ContentType 5 (prefix announcement) Content ExpirationPeriod 3600000 ValidityPeriod NotBefore 20181030T000000 NotAfter 20181124T235959 SignatureInfo SignatureValue
This prefix announcement object announces the prefix
/net/example. It is valid for one hour from its receipt, between the dates 2018-10-30 and 2018-11-24 (included).
Command Verb: 'announce'¶
This command announces a prefix using a prefix announcement object. NFD-RIB accepts this command as a signed Interest with the following name:
The Interest's ApplicationParameters element carries the prefix announcement object.
NFD-RIB converts this command into an equivalent
rib/register command. The route's origin is set to "prefix announcement" (=129).
The response is the same as the
Note: There is no 'unannounce' command. Instead, use
Interest Name /localhop/nfd/rib/announce/params-sha256=607a2bc7653eea18b47e92b84edc58bab5aaa321d4efb39ceeccc6cafbcbb3d1 MustBeFresh ApplicationParameters PrefixAnnouncement InterestSignatureInfo InterestSignatureValue
Assuming the enclosed PrefixAnnouncement is the one shown in the previous example, NFD-RIB should interpret this command same as
rib/register command with the following ControlParameters:
- Origin: 129
- ExpirationPeriod: 3600000; optionally, constrained by the ValidityPeriod of the PrefixAnnouncement