Communications News刊载CableIQ帮助确保更平滑的网络升级。国营农场保险公司想要在不造成麻烦的前提下将他们现有的结构布线系统升级至千兆以外网。IT经理坚信所有或大多数接口都可以支持千兆速度，但他们却没有一种快速、可靠的方式来测试现有电缆。Communications News刊载了CableIQ独有的透视电缆带宽解决问题的能力。
Tester assists move to GigE
Existing Category 5e network proves capable of handling higher-speed applications.
In just over 80 years, State Farm has grown from a small farm mutual auto insurer to one of the world’s largest financial institutions. With 79,200 employees and more than 16,700 agents servicing 71.6 million policies in the United States and Canada, the company has an extensive and varied cabling network.
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When Dave Bowling, the company’s telecom analyst, wanted to upgrade 60 State Farm users from Fast Ethernet to Gigabit Ethernet, he found that while the existing cabling infrastructure had been certified, years of moves, adds and changes left uncertainty about the network’s performance capabilities. Until recently, the headquarters campus in Bloomington, Ill., exclusively ran 100-megabit Ethernet over a Category 5e structured cabling plant. Then, the creative services group asked for an upgrade to Gigabit Ethernet for video editing capabilities, and wanted to eliminate delays experienced in transferring large video files.
While Bowling felt confident that all or most of the links would be able to handle the higher speeds, simply installing new electronics and running gigabit over the existing cabling without testing was unacceptable due to the risk of productivity losses and project delays if problems were experienced.
Luckily, when this situation arose, Bowling was evaluating a new tester from Fluke Networks designed for troubleshooting an active line and qualifying the link to determine its maximum speed capacity.
“Using Fluke Networks’ Cable IQ, one of our technicians had no difficulty qualifying all the links for Gigabit Ethernet,” Bowling says. “In about an hour, we were able to determine that all 60 links were capable of handling gigabit speeds. We also use the tester on a regular basis to quickly troubleshoot a wide range of connectivity problems, whether they involve cabling or electronics.”
“Cable IQ is only slightly more expensive than our normal troubleshooting tools,” says Bowling, “but it provides additional capabilities, including the ability to determine the maximum networking speed that an existing link is able to handle.”
According to Bowling, a single technician qualified many links in a short period of time. For each drop, the technician disconnected the patch cord from the NIC and plugged it into the tester. Then he ran the basic test to verify the cable connections and network electronics.
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Simply installing new electronics and running gigabit over the existing cabling without testing was unacceptable. |
After that checked out, he walked back to the telecommunications closet and connected the wiremap adapter to the far end of the link. He then ran the qualification test and, in only a few seconds, learned the results. The technician determined that every link was capable of handing Gigabit Ethernet. Since the speed of the network was upgraded, the tested links have worked without any problems.
“Cable IQ has also proved its value in a troubleshooting role,” Bowling offers. “Plugging it into an active link generates a diagnostic test of the cable, and simultaneously verifies switch speed/duplex settings. Our technicians can also use a patch cord to connect the instrument to the user’s machine and test his NIC card.”
The instrument provides diagnostic information, such as the existence of a wiremap fault on the patch cable, a crosstalk problem at the wall jack, or a large impedance change near the patch panel. “That’s quite a bit for an instrument that costs only about $1,000 and is as easy to operate as a conventional network tester,” he says.
“Our techs can now diagnose a much broader range of problems in the cable, switch and NIC than was possible in the past,” Bowling adds. “The tester generates wiremaps, and detects shorts, opens and length. What sets it apart is its capability to troubleshoot bandwidth-related cabling faults, such as crosstalk or large impedance mismatches. And its ability to evaluate live links is extremely valuable. In the old days, the techs had to carry around a laptop to validate a connection and that method sometimes failed because of configuration issues.
“Another unique feature is its ability to identify unused links or switch ports that can be freed up and reallocated,” he continues. “You simply unplug the cable from the switch port, plug it into the tester and put the tester into discovery mode. The tester will immediately tell you what is at the other end of the cable. Often, we discover that it isn’t even being used.
“This instrument, however, does not eliminate the need to certify cable,” Bowling cautions. “There’s no way that we are going to install a cable without ensuring that it meets the TIA-568-B standard. But in today’s dynamic business environment, certification is just the first step in the lifecycle of a cable link. Fluke’s Cable IQ provides an inexpensive and easy method of re-evaluating the cable at any point in time to determine its ability to handle current and projected needs. It also provides powerful troubleshooting capabilities.”