When troubleshooting a network outage, nothing is more annoying than going through dozens of hardware and software checks only to find that the problem is a bad wire or patch-panel connection.
While network vendors have solutions for Layer 2 to Layer 7, the root cause of most network outages still lies at Layer 1 - the physical layer, where wires and ports are plugged in. Help in dealing with these problems could be found among an array of monitoring, documenting and management tools now available for cable infrastructure.
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Observers and analysts say seven times out of 10, a downed network link is the result of a bad patch cable or faulty wall jack.
"Physical infrastructure is a key part of the whole network," says Jeff Dietsche, systems administrator for South Washington County Schools in Minnesota. Dietsche agrees that most problems with network connectivity tend to be of a physical nature, especially if cabling infrastructure is not up to date.
"There are lots of things that can go wrong that the average person doesn't realize," he says. "You only can have so many right angles on a length of cable. When ends are terminated, you have to make sure that too much wire shielding is not stripped off - any one of those things can cause real problems on a LAN."
Until about three years ago, all the cabling at the South Washington schools was pulled and punched down by Dietsche and his staff. Back then, he says, nine out of 10 network problems resulted from wiring trouble.
While the school district saved thousands of dollars by doing its own cabling, the hassle of dealing with network outages and the extra work the staff had to do pulling the cable itself was not worth it, he says.
"It doesn't pay to have your technical staff pull cable," Dietsche says. "A lot of organizations like to do that," because almost everyone has some experience with pulling cable or making patch cords. "But just because someone has experience doing something doesn't mean they're an expert at it," he says.
According to different studies by Frost & Sullivan and Gartner, midsize and large companies - with more than 1,000 workers - move or change around 30% of their employees per year, with an average labor cost to the IT department of around $250 per move. With many cable management system vendors promising savings of around 25% to 30%, businesses with large amounts of turnover or change could save up to $22,000 per year, these vendors say.
Companies looking for better ways to track physical connections are starting to turn to products that manage physical connections the way element manager or network management software applications can monitor servers and switches.
To get a better hold on the miles of network wiring, companies can use tools such as IMAP Textron's docIT software to discover all types of port connections on a network and map out a topology of LAN patch panel, wiring closet and wall jack components.
Textron's software runs on a Windows NT server, and a client PC application collects the data. Using SNMP-based information and software in network analyzer devices from companies such as Fluke Networks, docIT can discover connections types from Category 2 to 6 cabling, and fiber-optic connections. The software also can communicate with common PBX voice systems - such as Nortel and Avaya - and document voice connections and data.
For IT departments that want a constant update on the status of cabling infrastructure, the firm iTRACS has a system called Intelligent Structured Cabling Solution, which is a package of software, a monitoring hardware appliance and specially fitted patch panels and patch cords. The company says its products can help give customers a complete view of what is plugged into what on a network and alert them when physical links fail.
Each patch cord in the iTRACS system has an extra wire running through the plastic shielding, along with the four pairs of wires in a Category 5/6 cable. This wire plugs into a separate slot on the iTRACS patch panel and is used to test the integrity of the cable's connection and to signal that the cable is plugged in. The iTRACS patch panel plugs into a separate monitoring device, or network appliance, through serial connections. The monitoring appliance connects to a company's IP network, where an iTRACS Server database application, running on a standard Windows server, maps out and tracks the status of physical connections on the network. Patch cords and panels are available for fiber connections.
A Web client is used to view data from the iTRACS Server. The server also has application programming interfaces that can tie into network management or IT help desk applications, such as Hewlett-Packard OpenView. This could let physical cable failures or other events, such as unauthorized cable moves, trigger a centralized alert or trouble ticket system.
The system can be retrofitted onto existing patch-panel racks, says Rick McNeese, vice president of marketing for iTRACS, although replacement patch cables are required for the system. Racks with integrated iTRACS connections also are available for new equipment. McNeese says the cost of the system adds about 20% to the total cost of a new wiring rack and cable plant installation, or around $10 to $15 extra per port.
At the Kern County Department of Human Services, near Bakersfield, Calif., the iTRACS hardware recently was retrofitted onto the patch-panel infrastructure to monitor 3,500 switch ports in one building. The hardware/software product helps give the county's IT staff a better look at the layout of their network, says Kevin Morovich, network systems administrator.
"It helps when I troubleshoot the network to know if a patch cord is actually plugged into the proper subnetwork," he says. With iTRACS, he can look up that information on a Web page instead of hunting down the right physical connections in one of the dozens of wiring closets.
The system also can be used to physically locate PCs in the building by mapping out cabling links, then matching media access control address information to those links through the iTRACS server software. Morovich has used this to find users with PCs that send unnecessary or unauthorized traffic on the network.
Morovich also says the system can help find unused or underused network connections.
"Instead of adding a new switch, I can find out if there are unused ports on any patch panels out there [attached to active switch ports] and free them up," he adds.
The iTRACS software and hardware is resold by several cable plant providers, which integrate the gear into their own brand of patch panel equipment. Tyco, Ortronics, LANSense, Molex and AMPTRAC are among the cabling product companies that offer iTRACS' package.
"The system could be valuable for service provider networks or large enterprises, where you have hundreds and hundreds of connections in a telecom room," says Verne Anton, principal analyst with Gartner. "Any tool that can create an audit trail of changes made in terms of physical connections [could help IT professionals better manage their infrastructures]."
Avaya offers a similar cabling product with its Systimax iPatch cabling system, which it sells through Avaya channel and integration partners, and directly to large corporations. Like the iTRACS system, iPatch involves specially made patch-panel racks, cables and hardware that collects connectivity data from the racks and sends the information to a management server on the LAN.
Like the iTRACS system, a Systimax iPatch setup can be used to monitor the status of all physical connections on a network in multiple wiring closets from one workstation. The iPatch system also comes with wall jack equipment that can be used to monitor connection integrity down to the end-user port level, if desired. Avaya's package is not compatible with SNMP network management applications and does not support fiber-optic cabling.
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