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Commercial vs. DIY Solutions
Your network project will almost certainly consist of components purchased from vendors as well as parts that are sourced or even fabricated locally. This is a basic economic truth in most areas of the world. At this stage of human technology, global distribution of information is quite trivial compared to global distribution of goods. In many regions, importing every component needed to build a network is prohibitively expensive for all but the largest budgets. You can save considerable money in the short term by finding local sources for parts and labor, and only importing components that must be purchased.
Of course, there is a limit to how much work can be done by any individual or group in a given amount of time. To put it another way, by importing technology, you can exchange money for equipment that can solve a particular problem in a comparatively short amount of time. The art of building local telecommunications infrastructure lies in finding the right balance of money to effort needed to be expended to solve the problem at hand.
Some components, such as radio cards and antenna feed line, are likely far too complex to consider having them fabricated locally. Other components, such as antennas and towers, are relatively simple and can be made locally for a fraction of the cost of importing. Between these extremes lie the communication devices themselves.
By using off-the-shelf radio cards, motherboards, and other components, you can build devices that provide features comparable (or even superior) to most commercial implementations. Combining open hardware platforms with open source software can yield significant “bang for the buck” by providing custom, robust solutions for very low cost.
This is not to say that commercial equipment is inferior to a do-it-yourself solution. By providing so-called “turn-key solutions”, manufacturers not only save development time, but they can also allow relatively unskilled people to install and maintain equipment. The chief strengths of commercial solutions are that they provide support and a (usually limited) equipment warranty. They also provide a consistent platform that tends to lead to very stable, often interchangeable network installations.
If a piece of equipment simply doesn't work or is difficult to configure or troubleshoot, a good manufacturer will assist you. Should the equipment fail in normal use (barring extreme damage, such as a lightning strike) then the manufacturer will typically replace it. Most will provide these services for a limited time as part of the purchase price, and many offer support and warranty for an extended period for a monthly fee. By providing a consistent platform, it is simple to keep spares on hand and simply “swap out” equipment that fails in the field, without the need for a technician to configure equipment on-site. Of course, all of this comes at comparatively higher initial cost for the equipment compared to off-the-shelf components.
From a network architect's point of view, the three greatest hidden risks when choosing commercial solutions are vendor lock-in, discontinued product lines, and ongoing licensing costs.
It can be costly to allow the lure of ill-defined new “features” drive the development of your network. Manufacturers will frequently provide features that are incompatible with their competition by design, and then issue marketing materials to convince you that you simply cannot live without them (regardless of whether the feature contributes to the solution of your communications problem). As you begin to rely on these features, you will likely decide to continue purchasing equipment from the same manufacturer in the future. This is the essence of vendor lock-in. If a large institution uses a significant amount of proprietary equipment, it is unlikely that they will simply abandon it to use a different vendor. Sales teams know this (and indeed, some rely on it) and use vendor lock-in as a strategy for price negotiations.
When combined with vendor lock-in, a manufacturer may eventually decide to discontinue a product line, regardless of its popularity. This ensures that customers, already reliant on the manufacturer's proprietary features, will purchase the newest (and nearly always more expensive) model. The long term effects of vendor lock-in and discontinued products are difficult to estimate when planning a networking project, but should be kept in mind.
By using generic equipment that supports open standards and open source software, you can avoid some of these pitfalls. For example, it is very difficult to become locked-in to a vendor that uses open protocols (such as TCP/IP over 802.11a/b/g). If you encounter a problem with the equipment or the vendor, you can always purchase equipment from a different vendor that will interoperate with what you have already purchased. It is for these reasons that we recommend using proprietary protocols and licensed spectrum only in cases where the open equivalent (such as 802.11a/b/g) is not technically feasible.
Likewise, while individual products can always be discontinued at any time, you can limit the impact this will have on your network by using generic components. For example, a particular motherboard may become unavailable on the market, but you may have a number of PC motherboards on hand that will perform effectively the same task. We will see some examples of how to use these generic components to build a complete wireless node later in this chapter.
Obviously, there should be no ongoing licensing costs involved with open source software (with the exception of a vendor providing extended support or some other service, without charging for the use of the software itself). There have occasionally been vendors who capitalize on the gift that open source programmers have given to the world by offering the code for sale on an ongoing licensed basis, thereby violating the terms of distribution set forth by the original authors. It would be wise to avoid such vendors, and to be suspicious of claims of “free software” that come with an ongoing license fee.
The disadvantage of using open source software and generic hardware is clearly the question of support. As problems with the network arise, you will need to solve those problems for yourself. This is often accomplished by consulting free online resources and search engines, and applying code patches directly. If you do not have team members who are competent and dedicated to designing a solution to your communications problem, then it can take a considerable amount of time to get a network project off the ground. Of course, there is never a guarantee that simply “throwing money at the problem” will solve it either. While we provide many examples of how to do much of the work yourself, you may find this work very challenging. You will need to find the balance of commercial solution and do-it-yourself approach that works for project.
In short, always define the scope of your network first, identify the resources you can bring to bear on the problem, and allow the selection of equipment to naturally emerge from the results. Consider commercial solutions as well as open components, while keeping in mind the long-term costs of both.
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