The first step to selecting the right network tap for your network is to make sure you match the topology of the tap with the topology of your network.

Network tap technology is available in virtually all major topologies - currently, 10/100 Ethernet, Gigabit Ethernet, 10 Gigabit Ethernet, ATM, SONET, DS3, E3, T1, and E1.

Network taps for the LAN environment are available in both copper and fiber media types. Some taps are even equipped with port connectors of varying media types to allow a network device to monitor a network with a different media type. However, in order for a tap to create an access port between two devices, the network ports of the tap must match the topology of the network.

Fiber taps

When deploying a fiber tap, there are two main items to consider - the tap's split ratio and the tap's light source.

A fiber tap's split ratio is mainly determined by the tap's receiver sensitivity, its' transmitter strength, and cabling.

Each time an optical link is tapped, the link suffers from insertion loss. With each new access port that is created on a fiber link, more light gets "tapped out" of the network. This degrades the nework signal. In other words, the more "light" a fiber network has the better. Therefore, when deploying a fiber tap, you should choose a tap with the highest split ratio that will provide the adequate amount of light to the connected monitoring device.

The fiber splitters in the tap also need to support the light source used on the network. For instance a 1000Base-LX monitoring device will transmit data using 1300-nm lasers over single-mode fiber. If splitters are used that support lower-intensity LED transmission on this link, laser light intensity could cause network performance to degrade, so you'll want to ensure you select an LX tap with compatible fiber splitters. This ensures the insertion loss that is dictated by the chosen split ratio will be accurate.

Fiber taps are completely passive and non-powered.

Copper taps

Unlike fiber taps, copper taps do not split the network signal; they regenerate it. Regenerating the network signal means the signal gets amplified to a level where it can be received by the network devices connected to the tap.

To regenerate the network signal, copper taps must have power. When the tap is powered, the electrical signal passes through an open bypass circuit to an area of the board where the signal is regenerated and directed. All Datacom Systems copper taps come with dual redundant power supplies and some support Power Over Ethernet (PoE).

If power is not available to the tap, the bypass circuit closes, and the signal gets transmitted directly to the receiving network device.

An active tap uses a relay-based failover system for power fault tolerance. With our active taps, when power is lost to the tap, relays will re-establish the link which causes a 600 micro second delay. This delay may cause autonegotiation to take place and spanning tree to recalculate. To overcome this, the autonegotiation should be hard set to the desired speed and spanning tree for those ports set to portfast. When set up in this manner, if one of our active taps lose power, it will typically make no noticeable impact on your network.

Datacom Systems provides a wide array of network taps with different media types, media conversion taps, and media converters, so that you can connect network tools of one media type to a network of another media type. If you have multiple types of networks, such as LX and SX, or if you have coppert tools and a fiber network, you can easily find the right solution.

Link Aggregation