Perle Systems Technical Notes
Avoiding common mistakes in fiber-optic network deployment - Part Three
Problem #5: Not monitoring link integrity status
Despite auto-negotiation and other advanced network management features, when media converters are located between router pairs, the spanning tree and trunk-based processes used in most networks can struggle to properly communicate link integrity status between devices. If you are using a rudimentary media converter for your copper to fiber, multimode to multimode or multimode to single mode connection, what you have is a simple transceiver pair. While this is a lower cost option, there is a serious drawback. The end to end connection will always appear as if it is up and running even though the fiber connection may be broken or disconnected. The end devices, such as switches, continue to see the connection as healthy and never report a problem to an enterprise network management system.
For mission-critical links, it is important that these connections behave like a real copper to copper or fiber to fiber connection. This is accomplished through Media Converters with an onboard processor that continuously monitors the status of the links connected to its transceiver ports. If there is a break or failure in the link, both end devices become aware and react accordingly. An application on a server or a switch can then take the appropriate action should a link fail. Choose a Media Converter vendor with these Link Pass-Through features to provide link transparency troubleshooting capabilities.
Buyer Beware Note! Most Media Converters that are commonly available on the market claim to have a feature called Link-Pass Through. However, in most products, this feature is poorly implemented and does not work properly. Media Converters are not very expensive. If you find a very cheap product, this feature will not work in a predictable manner and you will not know when the link goes down. Only purchase from a quality vendor like Perle Systems.
Problem #6: Choosing the wrong media conversion platform
When deploying a network using fiber infrastructure, the media conversion hardware serves as the essential foundation gluing all of the infrastructure elements together. Businesses migrating to use more fiber in their architectures need to carefully evaluate the media conversion options available to them and make sure they match what the business expects from the network. Typically, businesses can choose between a modular chassis system or stand-alone converter.
For high density applications where multiple points of fiber integration are essential, the modular chassis format is widely considered ideal. The modular chassis also is the platform of choice in an application that requires redundant power. An hour of downtime can cost organizations thousands of dollars therefore, a redundant power system can be critical for companies involved in fail-safe networking.
Stand-alone Media Converters tend to be the simplest option, are ideal for company that needs to convert a single network node. These products are designed to be used in low to mid-density applications where a limited number of fiber converters need to be quickly implemented.
In addition to choosing the right platform, you need to choose the right media conversion provider. Look for a company that is committed to using robust and reliable components in their products. Specifically, ensure that they source from leading chip manufacturers to ensure product dependability.
Also, look at the company's diversity of product line. It is uncommon that a network will have a single type of connectivity or fiber need. As you upgrade different areas of your network the need for different converter types will be encountered. You do not want to be sourcing a new supplier every time you encounter a new conversion standard in the project.
Finally, choose a vendor that is committed to providing you the service you need. Do they publish their MTBF rates? Can you speak to a sales or technical consultant on the phone? Do they stand behind their products with a quality warranty? If network uptime is vitally important to your company, you need to choose quality products.
Making the transition to fiber-optic infrastructure is critical for many businesses. Due to the high cost of fiber implementation, networks featuring a combination of fiber-optic and copper cables may be the best option for most companies. This creates an environment where media conversion is critical. A poorly planned implementation can create major problems and escalate costs. Businesses looking to avoid these problems cannot rush into optical migration and instead need to focus on strategically developing their network. Media Converters play a critical role in this process.