|
Cabling Infrastructure From the February 2006 issue of Communications News |
ITIL helps keep network fit The health of Layer 1 will impact the performance of all other aspects of the network. by Pete Pela While organizations invest in tools that monitor the health of applications, packet flow and dozens of other network parameters, most completely ignore the foundation layer of those networks–Layer 1–where the cables, routers, switches, wall jacks and other physical devices interconnect. If that layer is not healthy, then the performance and security of the network layers above it will be negatively affected, no matter what tools and systems are operating.
Perhaps no recent initiative better reflects the realities of this approach than the IT Infrastructure Library, or ITIL–a set of best practices that delineates the various aspects that need to be addressed in order to optimize the delivery of IT services. While not laying out those practices step-by-step, as they will vary from company to company and need to be individualized, it does provide both guidelines and a framework for implementation. Included in the ITIL documentation is a section called the configuration management database (CMDB), which addresses the physical side of the network. When considering the multiple, yet often transparent physical connections in any end-to-end circuit trace, documenting and managing the physical layer is critically important in order to adhere to the principles set out in ITIL. There are three options for implementation: manually document and manage the physical layer, automate management, or use a mixture of both. Manually documenting the location and connection of every cable, wall jack, switch port and other device on the network is a daunting task, preventing most IT departments from tackling this project in the first place. The next challenge would be how to document this information efficiently and physically. It could be applied to a blueprint or CAD drawing of the building, but overlaying the information would be another painstaking, time-consuming task. The same applies to the numerous connections along every circuit. Any time a change is made, that change would again have to be documented, so in most cases the documentation is fluid. As a result, the challenge of documenting the physical layer is so significant it frequently is never overcome. Automation using the new breed of intelligent infrastructure management software provides an alternative. With this type of software, connections are discovered and then continually monitored electronically, from the server to the wiring closet to the wall jack, and finally to the end device, thereby generating documentation of the entire physical layer automatically (including overlaying it onto a CAD drawing of the building).
More productive, less costly Automatically surveying the physical network, creating the documentation and transferring it to a CAD drawing removes the human error factor. More importantly, the organization winds up with an accurate record of all connectivity points and connections, meeting the ITIL best practices requirement of establishing and maintaining a CMDB. In some cases, obstacles to a completely automated solution may require the use of a mix of automated and manual solutions. Without comprehensive and accurate documentation of the physical layer, achieving a state of best practices as set forth in ITIL is not possible. Any ITIL processes and procedures developed need to assume that the necessary IT documentation exists and is accurate. This includes the physical layer. A good example is the IT planning that forms part of service and application delivery. A portion of provisioning new users requires connecting them to the network. This will be faster, more reliable and more cost effective if the existing infrastructure is reused rather than installing new every time a new user connects to the network. Yet, without clear and accurate documentation, the most common course of action will be to drop new cable and install new devices.
documentation is important Ongoing management is another area that will benefit from a well-documented physical layer. This includes knowing what is connected to what, and who is connected to it. Yet, many organizations lack this basic but essential information. In one real life example, a virus penetrates the network through an infected PC. As the virus propagates, the antivirus software sets off alerts identifying the IP address of the affected device(s). Then there is typically a race against time to either find the infected device(s) or disconnect them from the network at the switch. Without accurate documentation, this exercise is like trying to push water uphill. You simply will not be able to react fast enough to restrain damage to the infected PCs alone. If you have intelligent infrastructure management in place, you can quickly get to the physical location of the virus or the switch port connecting it to the network and stop the spread before it becomes widespread. In another scenario, many organizations have cabinets of switch ports connected to cables that once served users, but now essentially lead to nowhere. Yet, they appear to be utilized because a patch cord was not recovered. This is both a security vulnerability and under-utilization of the switch capacity. Without accurate documentation, IT is unaware of this spare capacity, and simply adds more switch ports as users are added. By becoming aware of unused capacity, the organization can improve security, reduce its cost and save rack space. Utilizing spare capacity also qualifies as a best practice. Pete Pela is chairman, chief technology officer and
founder of iTRACS Corp., Tempe, Ariz. |