Assessing the bandwidth problem in your LAN

The argument is simple: more bandwidth, more information gets around, more work gets done, more efficiently. But the dilemma facing most network and IT managers is which technology to bet on for the network infrastructure – that "invisible" enabler that most organizations have come to take for granted.

Today in the Asia-Pacific, two main technologies come to mind when discussing bandwidth for the LAN backbone: Ethernet and ATM (Asynchronous Transfer Mode).

Fast Ethernet (100Mbps) has been the mainstay protocol for the modern LAN, and in many situations, it continues to provide the reliability and speed required to the desktop. But as processors get more powerful, more data-intensive applications are needed and new bandwidth-intensive applications (e.g. video on demand and other multimedia and collaborative applications) are crowding onto the LAN. For a growing number of organizations, there are doubts whether Fast Ethernet can continue to deliver the reliability and performance to which clients have become accustomed.

ATM technology, on the other hand, even with its high level of reliability, has already lost its appeal as a LAN backbone technology in the United States, and is starting to head down the same road in this region. Price is still the biggest letdown for ATM, coupled with the challenges and skill sets required in grafting together ATM and Ethernet technologies and infrastructure onto the same LAN.

So what choices does a network manager have? Especially when faced with a LAN that’s about to implode at any time, and a tight cap on his network infrastructure budget.

Gigabit Ethernet has arrived

In the recent past, Gigabit Ethernet could not really be implemented on either balanced, shielded copper cable or optical fiber cables. Neither option was practical in terms of cost nor implementation, since most organizations would already have an extensive Cat 5 copper wiring infrastructure in place to support their Fast Ethernet.

Fiber, of course, has its advantages. It travels longer distances, up to five kilometers, depending on core diameter, and is more secure, especially when applied over a Wide Area infrastructure. Fiber also has a lower bit error rate (BER), thus meeting most Quality of Service (QoS) requirements for high-bandwidth applications such as video-conferencing, etc.

Fiber, however, has disadvantages. For example, installation is comparatively difficult and very costly. While fiber is a solution for certain niche business needs, it doesn’t provide a solution that is cost-effective for most businesses.

Copper gathers momentum

Obviously, super high-capacity copper wiring (Cat 6 and above) is an alternative to optical fiber – except that the cost of ripping out and replacing the existing Cat 5 infrastructure can be as prohibitive as installing fiber. At any rate, few companies would choose to put up with the disruption this causes.

Now, however, it is not only possible but far simpler and more practical to run Gigabit Ethernet over existing Cat 5 copper wiring, to achieve an almost immediate tenfold increase in LAN capacity over Fast Ethernet, and keep costs firmly under control. Gigabit over copper is a natural in bandwidth evolution by providing affordable, high-performing architecture for increased network throughput due to increased backbone bandwidth.

Leading this evolution is 3Com, which, last March, broke through the price barrier with a new 10/100/1000 Ethernet server network interface card (NIC) at only $219. Other manufacturers have since followed the lead set by 3Com.

We can expect the market to move with similar momentum to when, in 1997, Fast Ethernet NICs dropped to $100. The price drop was so significant that the nature of the NIC business changed and helped solidify Fast Ethernet as the technology of choice. In similar fashion, the price drop for Gigabit over copper is again expected to drive mass implementation of the technology.

Simply a winning formula

Why is this rapid adoption virtually ensured?

In the design of an LAN, cabling is meant to have the longest life cycle. The high cost of ripping out existing cabling infrastructure convinces most companies to wait until it is absolutely critical before installing new cabling. Fiber costs 30 to 50 percent more than copper cables. Gigabit over copper immediately increases bandwidth for higher performance and reduces bottlenecks, and is available at a low cost of acquisition and ownership.

Above all, most industry watchers predict that despite the inroads fiber is making, copper will remain the pervasive infrastructure, with 84 percent of LAN ports remaining copper even by 2004.

Gigabit over copper has no significant reliability or performance issues when compared to Gigabit over fiber. Copper’s higher BER is overcome by the larger bandwidth, which more than makes up for the shortcoming.

Assessing your needs

No decisions are easy when it comes to assessing the current and future needs of a LAN, being able to predict (and prevent) bottlenecks, and ensuring that virtually any future application will run smoothly to the satisfaction of the organization’s network clients.

Which technology is the better bet depends first and foremost on the overall network design and its future requirements. If the IT manager prefers a single centralized location covering a localized, multi-site campus for all networking equipment, then the fiber may be a better option, due to its ability to travel longer distances (of up to five kilometers, depending on the size of the core diameter).

On the other hand, if the company already has wiring closets spread throughout the office, or building, then copper is the logical and economical solution. The split wiring closet stacks using switched Gigabit over copper excels in inter-departmental connections as it is a natural evolution of bandwidth over the same media.

Another consideration IT managers always need to look at is how to future-proof the network. Some questions to take note of when assessing this include:

* Will the company outsource IT requirement in the future, such as turning to ASPs?

* Will the organization turn to data-intensive applications in the future, like multimedia, video on the LAN, VoIP, etc? Will these applications require high security?

* What monetary and human resources does the IT manager have for IT investments?

Conclusion

Gigabit Ethernet over copper is redefining high-speed networking by providing high-performance connectivity over existing Category 5 UTP cabling. It is the ideal technology for growing enterprise networks due to its affordability, simplicity, and ease of installation and maintenance.

In evaluating the right Gigabit solution, the IT manager should search for switches and NICs that are affordable and simple to use, use common standards, but are reliable and sophisticated enough to meet growing business requirements. Most of all, companies should not have to pay extra for the complexity that many vendors have failed to remove from their products.

Gigabit implementation should be simple.

(The author is the technical manager of 3Com Phils.)