Is it possible to view the application protocol header? If yes, then what is the idea, algorithm or which libraries are needed? If this comes under the concept of hacking.
Unlike standard packet capture, which only reviews the information in the packet header, DPC captures and reviews the packet header as well as the data or payload the packet's carrying.
Unlike standard packet capture, which only reviews the information in the packet header, DPC captures and reviews the packet header as well as the data or payload the packet's carrying.
Then both tcpdump and Wireshark perform "DPC", presumably meaning "Deep Packet Capture", as they look at all protocols layers, for at least some protocols (and for a lot of protocols, in the case of Wireshark). They might not handle the protocols you're interested in, but there's probably NO software out there that handles every protocol.
(This is why I think the word "deep" is a bunch of marketing nonsense. It doesn't actually mean anything really significant, if it just means "stuff below the transport layer".)
Is it possible to view application protocol header?
Yes. Many protocol analyzers support that.
if yes. what is the idea ,algorithm or libraries.
The source code to those analyzers, which, in most cases, is proprietary. Wireshark, however, is open source, as is tcpdump.