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.

Future Bandwidth Requirements

It is rare that people think to factor in the growth of a company, or the launching of new products and services when estimating future bandwidth requirements. But, failure to make an accurate assessment of future bandwidth requirements can end up costing a lot of money. Unfortunately, estimating future bandwidth is both complex and often speculative. As an example, it might seem that doubling the number of employees in a company would result in a doubling of the network bandwidth demand. Rarely is it so straightforward, however. Consider that several of the new employees might be multimedia authors, who generally have much higher bandwidth requirements. Also consider that bringing on several new sales people means bringing on the back-and-forth communication between those sales people and all their customers. Perhaps the sales department has decided to host an in-house, web-based CRM implementation --- this could result in an increase in bandwidth requirements that are that are far out of proportion to the rest of the users on the network. Because of such factors as these, it is important that a network administrator have knowledge of the future plans for a business when planning a structured cabling implementation. Generally speaking, it is far less costly to "future proof" a structured cabling implementation than it is to replace the existing cabling once it becomes apparent that it is not sufficient to meet the demands of the network.

Your Budget

While working within a budget is certainly something one should consider, it must be understood that the difference in costs between Cat5e, Cat6 and optical fiber is insignificant compared to the costs involved in not using the correct conveyance media for current and future network requirements. The old adage that "it's better to do it right the first time" certainly holds true when planning your network infrastructure. Not doing it right the first time could cost your company far more than it saved by choosing an older technology or less expensive conveyance media, not to mention that not choosing the correct media could cripple a network and bring about the wrath of it's users. Because of this, current and future bandwidth requirements, as well as an understanding of your network environment should play a far more important role than cost in determining which type of cabling is best suited for your needs.