Although it taps into the traffic, the network tap does not modify it in any way, and the traffic on the network is unaffected by the act of monitoring or port mirroring. Since the monitoring is performed on a copy of the traffic by a device external to the network, via a tap network adapter, this deployment is often referred to as 'out of band'.In this manner, it acts as an ‘unobtrusive observer’ of the traffic, and just feeds a copy of the data to whatever device is attached to it. This provides full network visibility at that point. At the same time, however, if the tap or monitoring device should fail – it will in no way affect the traffic or its flow and thus ensures that the operating system remains secure.Taps come in both passive and active versions – each type having its own particular advantages for network monitoring in high density networks.Another effective type of tap is the fiber tap. Fiber optic taps are coiled into the optical fiber line and mirror all network traffic without introducing a point of failure and provide the secure access of network data in optical networks.
Niagara Networks offers passive or active taps.
Active Taps Are based on an active switching configuration for generating a “copy” of the traffic. “Copy” traffic is regenerated and there is no loss of signal power. In the case of power failure, “copied” traffic may be lost, but network traffic flows uninterrupted.
Passive Taps Are based on optical coupler (splitter) so that the tapped network point and appliance are always connected. Passive taps don't need a power supply in order for them to work!