Name of FIB entry / prefix registration

[yoursunny]

As I'm testing SVS interoperability, I noticed an interesting incompatibility between two implementations.
Packet trace: 1.zip

• ndn and tcp.stream eq 0 filter selects packets for impl-A.
• ndn and tcp.stream eq 1 filter selects packets for impl-B.

The Sync Interests from both implementations are encoded perfectly.
However, NFD would not deliver Sync Interests sent by impl-A to impl-B.

Upon further inspection, I noticed that the two implementations are registering prefixes differently:

• impl-A registered /ndn/svs/v=3 with ChildInherit flag.
• impl-B registered /ndn/svs with Capture flag.

The exact semantics of these route inheritance flags are not very important here, but NFD would have the following FIB entries:

• /ndn/svs/v=3 points to impl-A only.
• /ndn/svs points to impl-B only.

Longest Prefix Match rule is strictly applied among the FIB entry:

• When impl-B transmits a Sync Interest, NFD finds the /ndn/svs/v=3 FIB entry and delivers the Sync Interest to impl-A.
• When impl-A transmits a Sync Interest, NFD finds the /ndn/svs/v=3 FIB entry and cannot deliver the Sync Interest to impl-B.

This incompatibility can be resolved if the State Vector Sync protocol specifies the prefix registration behavior of the application.