NFD

The optimal implementation would be to create a LinkService that discards all outgoing packets, and use it with a dummy Transport.

However, since NullFace is not performance critical, I plan to keep it simple: use GenericLinkService with InternalForwarderTransport.

When InternalForwarderTransport is not connected to another InternalTransportBase subclass, it discards all outgoing packets.
The overhead in this approach is that GenericLinkService would still perform packet encoding, etc.

http://gerrit.named-data.net/2537