Differences in terminology and the absence of a 155 Mbps standard may cause problems.

Now that Category 5 UTP (unshielded twisted pair) and connecting hardware products are readily available from dozens of vendors, the battleground for market share has shifted from product availability and pricing to another important front: warranty guarantees. Buyers of structured cabling systems are now able to choose from a growing number of extended performance warranties, some of which claim to guarantee support of transmission speeds of up to 155 megabits for 15 years.

Caveat emptor

While, on the surface, these warranties may seem attractive, a closer look may yield some unexpected results that are not necessarily obvious at first glance.

* Terminology - In some cases, the performance representations made in the course of marketing a given vendor's extended warranty along with associated products will be expressed in terms of "megabits," or millions of bits per second. This is a reference to effective throughput, or, if you like, transmission speed. For those who care even a little bit, however, to whether or not a product warranty has anything to do with industry standards, it may be useful to know that all performance specifications germane to the use of UTP for networking applications (i.e., UTP cabling standards) are expressed in terms of megahertz, not megabits. Megahertz is an expression of electrical frequency, or cycles per second, and is a different unit of measurement than megabits. Megahertz is also used to express bandwidth.

Historically, megabits and megahertz have been used interchangeably in networking circles when referring to network speeds, since most networking schemes in use, such as Ethernet and Token Ring, were engineered in such a way that one cycle, or Hertz, was in fact used to represent a single bit. That, however, is not necessarily the case for higher-speed networks, such as ATM (asynchronous transfer mode), which performs at 155 megabits, but operates mostly at much lower bandwidths. What this means is that customers who think they're getting a 15-year/155-megahertz performance warranty may actually be mistaken. Thanks to encoding schemes, compression algorithms, and other advanced signaling techniques, many emerging network technologies, such as ATM, may indeed perform at an effective throughput of up to 155 megabits, but may actually only operate at much lower frequencies or bandwidths.

What this also means is that customers who do choose to install true, 155-megahertz systems during the course of their warranty - a not-too-unlikely scenario - should not be surprised to find that their warranty DOES NOT APPLY.

* Absence of standards - Another major problem with 155-megabit representations is that the only completed standards in place for high-performance networking over UTP limit their specifications to 100 megahertz. (Note: While it is true that the 155-megabit UTP physical layer standard for ATM is in place, the fact that the higher-layer remainder of the standard has not yet been completed means that there are still no standards-compliant, 155-megabit ATM systems commercially available. In addition, even the draft 155-megabit ATM standard operates at lower bandwidths or megahertz.) All standards-based networks in use today happen to operate within the 100-megahertz boundaries of the established, physical-layer standards for UTP (i.e., within the parameters of the EIA/TIA 568A standard, as well as within all other international standards for UTP). Generally speaking, all higher performing networks in terms of band rates, or megabits, are proprietary and may not be supported anyway because of the megahertz versus megabits issue.

Not only are there no industry standards for UTP performance beyond 100 megahertz, there are also no such standards for network systems per se - yet. The fastest Ethernet standards are limited to 100 megahertz or less; Token Ring is 16 megahertz; and FDDI is 100 megahertz or less as well. Beyond that, everything else is still on the drawing boards, or may not be supported by the vendor anyway (see 3rd bullet below). And so in the face of all of this, one could convincingly argue that performance warranties beyond 100 megahertz are of considerably less value than one might at first believe - if not completely meaningless in some cases. Once again, in these instances, buyers of extended warranties should not be surprised to find that their warranty DOES NOT APPLY.

* Scope - Even in cases where a vendor's extended warranty does indeed encompass systems that truly exceed the 100-megahertz industry standard, it does not follow that the same vendor will support all systems that do so. It's entirely possible that two systems operating at 120 megahertz may not be both supported by a vendor whose extended warranty applies to "systems of up to 155 megahertz." Vendors whose warranties feature this particular pitfall tend to protect themselves by limiting the scope of their guarantees at these higher frequencies to only those systems that they have chosen to certify at the time of the warranty.

Yet another variation on the theme of warranty scope is the notion of warranting "applications," above and beyond the product warranty per se. What this refers to is the vendor's warranty that certain systems they (the vendor) have tested and certified in the above-100-megahertz range will be supported by them above and beyond the performance warranty on the cable plant itself. This would theoretically apply to the use of network systems that operate outside of the Category 5 range of performance (beyond 100 megahertz), but whose vendors nonetheless support their products in that environment. There is at least one cabling vendor out there that offers this form of warranty. What's not clear about this is whether or not it makes sense for a product manufacturer to attempt to warrant something other than their own products. Warranting an application - an abstract concept to begin with - would seem to raise a number of enforceability issues, not the least of which is how one goes about determining whose fault the problem is when application problems occur. Once again, in these situations, customers should not be surprised to find that their warranty simply DOES NOT APPLY.

* Who does the work - Another important consideration in understanding extended warranties is the question of who does the work, and who holds the warranty. In some cases, the manufacturer's warranty is actually extended to the installer, not the customer, after which the installer "extends" or "assigns" the warranty to the customer. While these situations may be perfectly feasible, the buyer still needs to know that this is indeed what's happening, so that he or she can see to it that the extension or assignment, in fact, takes place. This protects the customer should the installer go out of business or disappear during the course of the warranty (i.e., the customer can then turn to the original manufacturer for warranty support).

Another aspect of the who-does-the-work issue is what happens when the customer chooses to do his or her own installation. What are the warranty implications of this decision? Clearly, a warranty is only as good, or as legitimate, as an installer's credentials to properly install the system. Manufacturers are not in the habit of extending warranties - much less extended warranties - to customers whose installers were not qualified, or certified by the manufacturers, to install the system in the first place. If customers choose to self-install their own systems, and at the same time hope to enjoy the full benefit of their extended warranties, they had better check beforehand to determine that the extended warranty applies to self-installed scenarios. Self-install customers may find there's more to the commitment required by the manufacturer than they had expected, including the possibility of having to commit to seven-figure purchases over a multi-year period. What does that have to do with extended warranties, you ask? Good question. But some vendors will impose these additional terms on self-install customers.

Mark W. McElroy is Senior Manager with Peat Marwick's Management Consulting Practice, Malvern, Pa. He is professionally certified by BICSI as a registered communications distribution designer (RCDD).