Net Optics Tap makes data stream monitoring magic

To test acterna's DA-3400, we used the Net Optics Copper Tap, model 96443 Passive 10/100BaseT Port Aggregator. This device allowed us to monitor both sides of the data stream without modifying the data. It can work its magic for you, too.

The tap is the proverbial bump in the wire. It modifies nothing, and unless you use a time domain reflectometer, you can't see it electrically. Yet it can monitor a wide load of network traffic and shunt those results off to network management tools such as the ones we tested.

The best part about taps is that they typically don't do anything to your connection if the power fails. The monitoring port would fail because it's aggregating both sides (TX and RX) onto a single port for ease of installation, but that's it.

Net Optics' Tap runs over 10/100 networks and is meant for installations where a NIC's reception capacity is greater than the average capacity needed to watch both sides of a full-duplex link. If the NIC exceeds capacity, Net Optics provides port buffering to handle up to 2MB of overflow in a full-duplex conversation. Using this tap instead of a SPAN (switched port analyzer) port means you get not only extended buffering, but also the ability to see both layer 1 and layer 2 errors appropriately filtered.

In testing the DA-3400, we could have used a nonpowered unit instead of the Net Optics tap, sending the TX portion to one interface on the DA-3400 and the RX portion to the other. As long as the management device supports it, this makes the resulting data clearer.

Although it might not be as flexible as designing your own monitoring solution using multiple NIC cards and SPAN ports, the NetOptics Tap is far simpler and speedier.