A riddle: When is a cable technician not a cable technician? The answer: When the cable technician is forced to act as a network test engineer. Not a very clever riddle, but very indicative of the current state of affairs in new network installations. Due to the increasing complexity of network systems, the increasing demand on complex protocols and services, and the severe physical requirements of new high-speed network connections the role of cable installation, test, and certification is evolving and becoming much more sophisticated. Understanding these new physical- and network- layer requirements of modern networks is the first step to surviving this shift in network implementations. The second is possessing the appropriate often costly tools to examine and certify the physical media according to these higher standards. With the two together, you can provide simple and reliable network protocol and service verification to ensure that the network, once installed, will function as designed.
Cable test and verification procedures have long been a part of the cable installation technician’s repertoire. This certification occurs prior to the inevitable alterations by local IT departments and tech-savvy employees. Daily operations (and mishaps) within the wiring closet will inevitably affect the quality of the network. In other words, test and certification procedures are also important to the customer—who needs a working cabling system, and needs to know that they are building their complex enterprise systems atop a stable foundation. They are equally important to the installation technicians themselves, helping to identify and rectify defects or errors quickly so that installations run more smoothly. At the very least, proper certification documents the quality of their own work, providing a clean demarcation of responsibility when a new installation is handed over the customer.
However, networks have changed over the years, making the clean line a blurred one. While the cable design may be simpler, the number of protocols, services, and devices that are critical to a network’s operation has grown. Many networks possess Virtual Private Network capabilities (VPNs), intranets, extranets, and a host of security- and encryption- mechanisms and protocols to support it all. Simple web servers have evolved into complex servers to support e-commerce, and may include entire clusters of servers, balanced across the network using yet more network sophistication. While it is still necessary to certify the physical cable plant, the modern network demands additional scrutiny, if these types of services are going to work. The cable technician, as a result, is being forced to evolve—to investigate and understand the inner workings of network protocols.
The solution requires both increased training and expertise among cable technicians or new tools, which can perform these extensive tests automatically. These devices must not only verify cabling can support Ethernet datarates up to 10Gbps, but also possess the capabilities of protocol analyzers and be able to automatically detect and test these types of complex services. Where a hand-held cable test unit would historically be used to verify that line interference and signal-to-noise ratios (SNR) were within acceptable limits, these new tools will scan the network for critical devices and servers, verify their operation at the protocol layer, and even test performance to each of these key components. In other words, the inconceivable suite of tests discussed above becomes very conceivable. The cable installation technician evolves into a network technician, and everyone benefits.
Specific lines should be tested to ensure that each of the network services mentioned earlier—DNS servers, DHCP, etc.—are responding appropriately. As previously noted, there are many of these services; to avoid undue difficulty in verifying them all, a network performance analyzer should be used to automatically discover and test these devices, and to ensure there are no overlying IP configuration errors that may interfere with network operation. By locating network services and servers, and then measuring their performance and reachability, higher-level problems can be identified at the outset, and will also greatly assist in network troubleshooting later on. With the right approach, and the right tools, a complex and difficult—and very necessary—task becomes much more manageable. As networks rely more and more on higher-level services, the initial certification of the network expands to include higher-level tests as well in order to compensate.
Another riddle: What do you get when you cross a cable tester with a network performance analyzer? The answer to your prayers. Again, not a particularly clever brainteaser, but true nonetheless. The 10Gbps network performance analyzer is a key tool in the successful diagnosis of a modern network; these devices are typically complicated and often very expensive. A hybrid tool, such as the new Softing NetXpert XG (available in 1G, 2.5/5G & 10G models) places the capabilities of datalink and protocol testing into the hands of the cable technician, is more desirable. Cable test equipment remains as important—if not more, and can not be abandoned or replaced. The two must be combined and used together, in as simple and cost-effective a manner as possible.
Networks are dependent upon new protocols and services that cannot accommodate the ill effects of a poor cabling plant. A simple case of jitter or the occasional malformed packet can cascade through a complex sequence of network services and snowball into a major problem before the real network communication even begins. Understanding these complex dependencies may be impossible to all but the highly trained network technicians. However, these physical- and network- layer requirements can be easily examined using the appropriate test devices, placing network certification back into the hands of the cable technician. The initial and most fundamental step in a new network implementation—the physical test and certification—has simply evolved; new technologies and equipment have been developed to remove the conundrum of convolution from the modern sophisticated network. After all, nobody likes riddles.
Author: Davy Edgar, Softing IT Networks Limited
