How to Determine Your Network Cabling & Wiring Needs

The conveyance media you choose for your structured cabling implementation is determined by many factors, the most important of which are your current bandwidth needs, your network environment, your expected future bandwidth requirements and your budget. This article will address each of these primary concerns in an attempt to help you identify which cabling solution will best meet your specific requirements.

Determining Your Current Network Bandwidth Needs

Your primary concern in determining the type of cabling to use is your network’s current bandwidth requirements. This figure can vary greatly based on the size of the network (i.e. the number of workstations connected to the network). A small network of 15 workstations will generally have much lower bandwidth requirements than a network that needs to support 100 workstations. Future growth should also be factored when considering network size. If your company is expecting to double the number of employees over the next two years, then you can expect your network bandwidth needs to increase accordingly. To complicate matters further, you must also factor in the type and volume of the data traffic that your network will be supporting. For example, a small multimedia and graphic design firm with only 10 workstations will likely have much greater bandwidth requirements than a law firm consisting of 25 workstations. Again, this is due primarily to the type and volume of the data one can expect in each work environment: a single user transferring a 5-minute high definition video across the network can easily consume more bandwidth than 20 users opening MS Word and Excel files.So how do you accurately determine your network bandwidth requirements?There are several ways to analyze network traffic, but the best and most accurate method is to utilize a tool called a network analyzer. Among the simplest and most ubiquitous of these tools is a utility that is built into all flavors of Windows servers called Network Monitor. The Network Monitor utility gives detailed insight into traffic on a network segment and can detail broadcast traffic and specific packets transmitted to or from a machine. There are also several other third-party products such as Ethereal (free), as well commercial analyzers such as Network General Fast Ethernet Sniffer, Cinco NetXRay, AG Group EtherPeek, Novell LANalyzer for Windows, and Intel LANDesk Traffic Analyst among many others. It is important to note than when using a network analyzer to monitor your current network’s bandwidth usage, that you sample data over the course of several days (or even weeks), and that you do so throughout different times of the day. Doing this will ensure that you make the most accurate assessment of your network’s bandwidth requirements.

Your Network Environment

Your network environment plays a large part in determining the best type of cabling you should use. While optical fiber offers the fastest possible bandwidth and is the best medium for “future proofing” your network, certain environments are ill suited toward fiber optic installation. Unlike twisted copper mediums like Cat5e or Cat6, optical fiber is prone to transmission problems due to dirt and scratches on the fiber. This can be typical of dirty or dusty mechanical closets, equipment closets, and any rooms that are not clean or friendly to fiber technology. In such cases, twisted copper solutions might be the best way to go. Alternatively, certain environments cause problems with twisted copper mediums. Although Cat5e and Cat6 have much improved noise immunity than their twisted copper predecessors, they are susceptible to high RF (radio frequency) and EMI (electromagnetic interference). Hospitals for example, have tremendous RF interference problems over twisted pair cabling. A Cat5e or Cat6 cable running alongside a CAT scanner or NMR (nuclear magnetic resonance) scanner would be rendered virtually useless due to RF interference. In such environments, optical fiber is the ideal solution as it is all but immune to such interference.