The term TAP is an abbreviation and stands for Test Access Port. A Network TAP, also called Ethernet TAP, establishes a passive access point to a network connection, with which the data signals transmitted via the cable can be read and evaluated for analysis purposes.

Once installed, a TAP can be used to make all data traffic available for various monitoring applications transparently, quickly, easily and without affecting the active network line. A Network TAP operates on OSI Layer 1 and has no MAC address. Therefore it is invisible in the network and cannot be detected by any attacker. This is essential, especially in network forensics and security, as otherwise criminals could be aware of the presence of the TAP.