  The Named Data Networking (NDN) and Content-Centric Networking (CCNx)
architectures are the leading approaches for content-centric networking, and
both require using Interests (requests that elicit content) and maintaining
per-Interest forwarding state in Pending Interest Tables (PIT) to store
per-Interest forwarding state. To date, PITs have been assumed to be necessary
to enable native support for multicasting in the data plane, such that
multicast forwarding trees (MFT) are established by the forwarding and
aggregation of Interests using PITs. We present a new approach to
content-centric networks based on anonymous datagrams that provides native
support for multicasting, but does so without the need to maintain per-Interest
forwarding state. Simulation experiments are used to show that the proposed new
approach attains the same end-to-end delays for multicasting while requiring
orders of magnitude fewer forwarding entries.
