VSS (Visibility, Stealth, Security) monitoring offers multiple hardware products that allow for the monitoring of network traffic, primarily for security (routing traffic to intrusion detection and/or content monitoring tools) or network performance uses. Their network taps, in particular, are typically deployed inline between switches and routers, and enable the stealth monitoring of all traffic passing through the tap. The device itself is invisible to the individual elements of the network (i.e., the switch still thinks it's connected to the router and vice versa).

In a traditional tap, a pair of ports--i.e., 4 ports in all--is provided both for the actual network links (one to the switch, the other to the router, for example) and to the monitoring devices; so that the monitoring device can capture and examine traffic from both sides of the link. In the aggregation tap line of offerings from VSS, however, the traffic from the 2 network ports is combined and streamed to the monitoring devices over a single port (hence, the traffic "aggregation"). I.E., the aggregation taps still provide dual ports for the actual network connectivity, but then provide only a single port for each connected monitoring device; requiring fewer overall ports on the monitoring gear itself.

An additional feature available on all of the vendor's inline taps is their "Link Safe" technology, which enables the taps to automatically monitor both sides of the network link and shut down the other link in the event that one side fails (so that attached routers or switches will see the link failure and correctly invoke redundant connections, if they have them).

Multiple flavors of aggregation taps are available from the vendor; providing both the ability to combine multiple network segments into a single monitoring port, and splitting a single network segment to be made available for multiple monitoring devices. Copper, Fiber, and converter (from copper network to fiber monitoring or vice versa) configurations are available.

Some (but not all) of the currently available gear include:

- 10/100 1x3 SNMP Injection Tap: Provides 2 ports for the network link, and makes the combined traffic from those two ports available to up to 3 monitoring devices through 4 monitoring ports (the first 2 monitoring ports are dual ports as in a traditional tap; the remaining 2 monitoring ports are aggregated). The SNMP Injection Tap features support for SNMP management and can also receive automatic data injection from one of the devices attached to the monitoring ports. Also available without SNMP and Injection features.

- Gigabit 1x2 Fiber (network) to Copper (monitor) aggregation; LX and SX models available. Gigabit 1x2 all fiber model (network and monitor ports) also available.

- 10/100/1000 2x1 (2 networks combined to 1 monitor). The 10/100/1000 2x1 is also available as a converter (TX network to SX monitor).

- 8x8 Distributed Filter Tap, the newest entry in the product family, with eight ports for network traffic, four monitoring ports, and four configurable ports that can be setup for network, monitoring, or pass through needs. The 8 network ports are served in copper (10/100/1000) or fiber flavors; while the four configurable ports are all copper and the four monitoring ports are all SFPs. Depending on model and configuration, up to 12 networks (6 in the fiber flavored models) can be monitored across the 4 monitoring ports; with Tap or SPAN deployments both supported for the copper ports.

The VSS monitoring Aggregation Tap offerings are available now. Pricing for the new 8x8 Distributed Filter Tap is approximately $16,000.

Visit the VSS monitoring Web site for further information.