There are two parts to jNetPcap SDK. The first part is the libcap wrapper, which provides nearly all of the functionality of libpcap native library, in a java environment. This wrapper, just like libpcap itself, is lowest level API in jNetPcap SDK.

The second part is the packet decoding framework. This is a collection of packages that allows a captured packet to be processed and decoded. The programmer then uses a set of java classes called protocol headers, to work with these decoded packets.

The libpcap wrapper is not dependent on the packet framework and can work completely without invoking any of the packet framework api. The packet decoding framework is also independent of the libpcap wrapper. It provides methods that can scan and decode any packet buffer in memory, not just the ones delivered from the wrapper.

Of course, the two API are linked seemlessly and you can ask libpcap wrapper to deliver fully decoded packets to you. This approach provides the best of both worlds and lets you work in any mode you choose.