Tag Archive: switches

cableOver the years, I have seen a lot of first-rate cabling jobs done by true cabling professionals, but I am also surprised with the magnitude of shoddy work done by people claiming to be professionals.  The result of the latter is that I am tougher than most about vetting cabling companies.  I am not a cabling professional, but I understand the technology, test cables, and know how they are supposed to be wired.  I am also capable of doing fundamental cabling jobs when absolutely necessary.  What passes for network cabling in some instances is abysmal.

Some examples include:

  • Cables stapled to the wall – This is particularly ineffective, especially when the professionals doing it put staples through the cables.
  • Improper cable termination – CAT 5e and CAT 6 cables, the most widely installed cables today, are only supposed to be terminated in one of two methods.

As a technology consultant, it is my job to thoroughly check and maintain network infrastructure, such as cabling, that can impact the performance of my clients’ systems.  Though many homes and public places utilize wireless, most corporate environments still use gigabit Ethernet in lieu of wireless due to a demand for greater network speed and security.  With that in mind, managing cabled networks and minimizing cabling problems will continue to be a high-priority item for the foreseeable future.

Here are eight things you can do to help prevent cabling nightmares:

1. Run ANY planned cabling work by your primary IT manager or consultant.

2. Hire qualified cabling professionals and check their references.

3. Centrally locate wiring whenever possible. This means that you not only try to put the wiring in the center of your office, but also try to put all of the wiring in the same place, which is hopefully where your servers are stored.  This is, of course, an ideal.  Wiring centers sometimes wind up where they fit into an office floor plan.  If you have an existing wiring center and you are adding new drops, it will likely make sense to have the new cables run from the existing wiring center.

4. Have all patch panels and office jacks clearly labeled. This isn’t hard to do when things are first installed, but if it isn’t done you will pay over and over again for people to try and figure out what is what.

5. Get separate drops for voice and data. Though some think this does not matter because workstations can be plugged into most VOIP phones, having separate voice and data drops is an important issue.  Separate cable runs cost very little incrementally, allow you to easily segment VOIP network traffic, and maximize your network bandwidth.  Most of today’s VOIP phones are Fast Ethernet (100mb) network devices not gigabit Ethernet network devices.  So the result of using a single drop for voice and data in an office is that your phone gets plugged into what may be a gigabit Ethernet network jack, and forces the connection down to 100MB.  The user’s workstation is then typically plugged into the VOIP phone, but the network connection is 100MB, so the PC connects at a speed that is theoretically a tenth of what it could be.  This may be less of an issue in the future, but most of the places I work would easily notice this difference and be unhappy about it.

6. Have the final work checked by your primary IT manager or consultant before you pay the cabling company.

7. Create a network diagram with detailed wiring information and keep it up-to-date.62-200

8. Finally and most importantly, buy a cable tester, learn how to use it and test any cables you put into your network.  A tester only costs about $50 and it can easily save you $500 or more.  It isn’t unusual to find bad network cables shipped with new devices or in a group of brand new cables.  If you use a bad cable, it can cause network latency and other workstations issues which can take a significant amount of time to troubleshoot and cost your business time and money.

Recently, I reviewed an interesting network cabling job done by a contactor.  He had removed about three feet of the cable jacket from the runs he made into the wiring center, leaving all the wires exposed, then terminated the wires, and plugged them into the switch.  Of five cables that he ran, four cables were incorrectly terminated, and they were terminated in four different ways.  In this case, it is clear from was left behind that he had no idea what he was doing, but without a cable tester you wouldn’t know that.

Historically, the only consistency I have seen is a failure on the part of people doing cabling to check all of their work.  It literally takes an extra minute to check each cable run when you are done.  I expect that out of every dozen cable runs I check, I will find one that is incorrect.  On rare occasions, I’ll admit that I am pleasantly surprised by a perfect job.

About the Author: Kevin Shea is President of InfoSystems Integrated, Inc. (ISI); ISI provides a wide variety of outsourced IT solutions to investment advisors nationwide.

For details, please visit isitc.com, contact Kevin Shea via phone at 617-720-3400 x202 or e-mail at kshea@isitc.com.

Yesterday, I fielded a call from one of our clients that generates reports for several thousand accounts using our reporting engine.  As part of their reporting process, they extract data from Axys and import it into a database that facilitates data quality reviews and enhanced PDF reporting via Crystal Reports.

My primary contact at the site phoned me to let me know that part of our process, which took 20 minutes last quarter, was still running after two hours.  We immediately established a remote session to review the issue.   In the past, we have experienced some issues with individual PCs processing at slower speeds due to poor network infrastructure, but more recently this firm invested in better network hardware to support their rapidly growing business.

We play a limited role for this client and focus on their quarterly reporting and billing systems.  Though we are IT experts, it is not our responsibility to oversee and manage their IT infrastructure; however, at quarter end, a processing issue where systems are operating at a fraction of their normal speed rapidly becomes our problem.

I am very familiar with the bottlenecks that can slow Axys performance.   The most critical of these is network speed.  100MB Ethernet (full-duplex) is an older standard, and we still find it in limited use at many offices.  Gigabit Ethernet (full-duplex) is the current standard that should be in use by nearly all investment firms.  Theoretically, gigabit is ten times faster, but you won’t see that in practice.  You actually get six to seven times the performance of 100MB Ethernet with gigabit Ethernet over decent cabling.

Our system is normally connected to the file server that hosts Axys via gigabit network connections.  A quick check of the system revealed that it was connected to a gigabit switch.  We reviewed a few other things to make sure that there wasn’t a performance issue specific to our system.  Everything we looked at pointed to a problem with their environment.  I was fairly certain that, somewhere between our system and the file server hosting Axys, we were not connected at gigabit speed.  We still needed to identify where the breakdown was occurring.

My technical contact at the firm first assured me that all of the systems were connected to gigabit switches, and nothing had changed since last quarter.  We discussed the wiring of the network in detail and I was eventually able to find out that they had added a new Dell switch in the server room, but assured again that it was a gigabit switch.  I asked them to double-check the switch and let me know the model.

Though most of our own experiences purchasing equipment from Dell are good, Dell isn’t perfect.  Perhaps the Dell sales rep didn’t know one gigabit switch from another.  Our client thought they had purchased a managed gigabit switch where all ports were gigabit.  They had, in fact, bought and installed a 100MB managed switch with two gigabit uplink ports.   Further discussion revealed that the gigabit uplink ports were not being used either.

For those not familiar with network nomenclature, the primary switch to which all of your other switches, routers and servers are connected is considered your network backbone.  It is a best practice to implement a backbone that has throughput greater than or equal to that of the devices connected to it. 

When two network devices auto-negotiate to communicate with each other the maximum speed is usually the highest speed commonly supported by both devices.  Other environment specific issues, such as the quality of cabling between two devices, can further degrade the speed at which two network devices communicate.

In this particular case, our client had unknowingly installed a switch that was forcing all of their servers with gigabit Ethernet to communicate with the rest of the network using 100MB Ethernet instead of gigabit.  Users that were not connected directly to the backbone had a gigabit connection though another switch, and assumed that everything was fine.

The short-term fix for this client was to connect their file server hosting Axys to one gigabit uplink switch and use the other uplink to connect to their larger gigabit switches.  They also called Dell and had them send the right switch overnight, which they installed today.

Having an up-to-date network diagram is a best practice.  If you don’t have one, have your technical staff or IT provider create and maintain a network diagram documenting your systems, so you can proactively manage problems with network performance and reliability.

About the Author:
Kevin Shea is President of InfoSystems Integrated, Inc. (ISI); ISI provides a wide variety of outsourced IT solutions to investment advisors nationwide. For details, please visit isitc.com or contact Kevin Shea via phone at 617-720-3400 x202 or e-mail at kshea@isitc.com.