What is a Network Tap

A network tap is an external network device that creates a “copy” of the traffic for use by various monitoring devices. It allows port mirroring. The tap device is introduced at a point in the path of the network that is felt should be observed, so that it can copy data packets and send them to a monitoring device. The network designer will decide where that significant point for the network tap should be placed, based on the reason for observation: data gathering, analysis, general network monitoring (such as for saturation and latency), or more critical, such as for intrusion detection, etc.

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.

Taps come in both passive and active versions – each type having its own particular advantages for network monitoring.
Another effective type of tap is the fiber tap. Fiber 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.

A chart showing where network taps sit within a typical network architecture

Niagara Network Taps

Niagara Networks offers passive or active taps. A wide range of connectors and fibre types are supported.

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

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!