TAP-dancing into GigE monitoring

By Amy Storer, News Writer 07 Mar 2005 | SearchNetworking.com

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In response to the increasing market demand for an accurate analysis of full-duplex gigabit networks, network performance vendor Network Instruments LLC today released a network testing hardware network.

NI's new Test Access Points (nTAPs) are hardware components touting high-volume data capture and link performance. The nTAPs are installed between a switch and network device to copy, or "clone" the full-duplex data stream into an analysis device without affecting network traffic.

The full-duplex data stream cloning is important because, unlike switched port analyzer (SPAN) features or port mirror mechanisms on a switch, the nTAP cannot drop packets or add latency to switch performance.

These devices, also known as test access probes, are passive to allow for a continuous traffic flow. They also allow network-based intrusion-detection system sensors to operate efficiently without interruption.

TAPs can send traffic data to the monitoring device by splitting or regenerating the network signal. Neither splitting nor regeneration introduces delay, or change the content or structure of the information contained in the packets.

George Hamilton, a senior analyst with Boston-based research firm Yankee Group, said this alternative to deploying network probes on a mirrored switch port is valuable when real-time troubleshooting is a high priority.

In general, Hamilton said, TAPs are more widely used when the environment is not distributed. "Too many locations, and it becomes a hassle to deploy probes," Hamilton added. "If using probes, it's better to deploy as a TAP rather than on a mirrored switch port when it's a core link or a link supporting critical or time-sensitive apps such as VoIP."

Douglas Smith, president of Network Instruments, referenced a recent Dell'Oro Group study that found more companies are purchasing Gigabit Ethernet (1,000 megabits per second) ports than Fast Ethernet (100 Mbps) ports for modular Ethernet LAN switches. He said NI developed the nTAPs primarily to meet increased demand for devices that can keep pace with GigE speeds.

"The world is moving to gigabit analysis," Smith said. "Of course, these networks are faster, but they are also full-duplex. When your total aggregate link utilization exceeds 1,000 megabits per second, switch SPAN ports no longer function and you must use a TAP to ensure high-volume data capture."

Resource Communications Inc., a Downers Grove, Ill.-based data communications provider, is a technical partner that works with many NI customers currently using TAPs from other vendors. Bob Cook, vice president of test sales at Resource Communications, said NI's nTAP line is cost-effective, flexible and innovative.

"The new GigE Copper TAP provides the ability to monitor a GigE copper link with an analyzer equipped with TX, SX, LX or ZX all with the same TAP," Cook said. "These are elements that weren't collectively available in a vendor's network TAP previous to today's announcement."

The nTaps have vast competition, according to Hamilton, from vendors such as Finisar Corp., WildPackets Inc. and VSS Monitoring Inc. However, Hamilton said NI's offering is broader than that of the other vendors because its core product is the analyzer, and the nTAPs are just a way to deploy the analyzer.

Also, Hamilton said this product differentiates NI because it now has its own TAP. Competitors such as WildPackets use TAPs from third-party partners like Net Optics Inc. But Hamilton said NI's analysis software is really the crown jewel of the offering, and that will be what brings in the big bucks.

Hamilton said NI's price fares well in the marketplace, as NI's most expensive nTAP is under $2,400, while TAPs from other vendors, such as Fluke Networks, may include monitoring or testing software but cost more than $20,000.

The nTAPs are available today and the 10/100 Copper nTAP begins at $395; the 10/100/1000 Copper nTAP is $995; and the 10/100/1000 Conversion nTAP starts at $1,995. Single-channel Optical nTAPs are $395 with four-channel and six-channel rack-mountable units available for higher port densities starting at $1,795.

>> For more on network monitoring, peruse our Guide to Network Performance Management

Tags: Network Performance,  Network Documentation,  Network Monitoring,  Network Management Software,  Ethernet,  VIEW ALL TAGS

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