Taking Note of Patch Panel Technology

Three types of patch panels (wireless, electronic, and intelligent) have benefits and drawbacks. Knowing what works best where ensures problem-free operation. When it comes to making a move, add, or change in a voice/data cable plant, sending a technician to perform physical changes at a patch panel in a wiring closet is not a simple task. In fact, it is one of the most time-consuming and cost-intensive

Three types of patch panels (wireless, electronic, and intelligent) have benefits and drawbacks. Knowing what works best where ensures problem-free operation.

When it comes to making a move, add, or change in a voice/data cable plant, sending a technician to perform physical changes at a patch panel in a wiring closet is not a simple task. In fact, it is one of the most time-consuming and cost-intensive operations in the overall support of a communications system. One industry research group recently estimated that the cost to maintain local area networks (LANs) consumes 84% of a network manager's budget, 44% of which is spent on physical management and troubleshooting.

However, there are types of patch panels currently available that can help reduce the time and cost associated with such activities. These "unconventional" patch panels each have benefits and drawbacks, depending on the application.

Some definitions. Before getting into the subject of what's out there in the way of electronic patch panels, let's first attempt to define the term. An electronic patch panel is a device that enables cross-connecting electronically; that is, without the necessity of making any physical changes by hand using patch cords or other cross-connect components. This definition also implies the ability to make such changes from a centralized station or terminal such that the patch panels controlled in this manner can be remotely monitored and/or configured by a central operator. The promise of this technology could be very appealing, since it would effectively eliminate the need to dispatch technicians to wiring closets every time a cross-connect of some kind (i.e., a move, add, or change) is required.

The ideal electronic patch panel should also be very flexible and intelligent. It should not only enable the making of distributed cross-connections from a central point, but should also support mixed media cross-connections. For example, you may want to cross-connect horizontal unshielded twisted pair cables (UTP) to fiber in the backbone or, at a minimum, make UTP-to-UTP connections. In any event, the ability to support opti-electronic transitions in media would seem to be of some value in certain cases.

In practice, an intelligent electronic patch panel would give a network manager the ability to make cross-connections from any circuit in horizontal wiring to any circuit in the backbone subsystem without ever having to leave his or her desk. The ideal system would also enable cross-connections between two or more circuits in the horizontal subsystem, up to and including daisy chained circuits.

Product classifications. A high level review of what's out there in terms of what we'll generally refer to as "unconventional" patch panel technology yields products in at least three different categories. In spite of their differences (which we'll describe), all products in these categories have one thing in common: They are designed to minimize, if not totally eliminate, the need to physically make moves, adds, and changes as traditionally done by technicians using patch cords and cross-connect wires in wiring closets.

The three categories, according to our view of the world, are:

  • Wireless patch panels,

  • Electronic patch panels, and

  • Intelligent patch panels.

Wireless patch panels. Products in this category fit the description of "unconventional" patch panels, but are far from electronic or intelligent. In fact, they are passive devices. This is an important distinction compared with the other two categories, which themselves may be wireless, but not passive. Wireless patch panels are also wireless only to the extent that they avoid the use of external patch cords to achieve cross-connections. Instead, they rely on internal cross-connections using hard-wired modules that connect "input conductors" or jacks to "output conductors." This results in a straight-through cross-connection of media such that each conductor's identification is maintained all the way through the cross-connected circuit (e.g., the Tip of pair 1 is maintained; Ring of pair 1 is maintained; Tip of pair 2 is maintained; etc.). You typically base wireless patch panels designed for copper connections on 2-, 4-, or 8-wire configurations.

With wireless patch panels, the assumption is "normal" prevails for most jacks most of the time, and you should only use patch cords to make changes or deal with the exceptions. Therefore, you can use patch cords with wireless systems, but only when deviations from the norm are required. Insertion of a patch cord into a wireless patch panel breaks the internal cross-connection, thereby freeing the input channel for reassignment to another output channel at the user's discretion.

You must still perform all of the physical administration of a wireless patch panel on a remote basis by technicians inside wiring closets. You cannot control wireless systems, according to our classification here, and therefore they are not addressable by remote devices from a central management station of any kind. Wireless systems also come with passive components (not electrified in any way). In terms of appearance, wireless patch panels closely resemble conventional patch panels and are comprised of RJ-type jacks on their front panels.

Electronic patch panels. Unlike wireless patch panels, electronic patch panels are active in the sense that they are electrified. (See Fig. 1, on page 56 of original article). Therefore, they are capable of sensing, capturing, and storing certain operating or status conditions. Then the network manager can handle them properly. However, you cannot manage electronic patch panels, again according to our classification, from a remote centralized station and still require physical handling by technicians inside wiring closets.

Examples of functionality common to electronic patch panels include "sensing" of patch cord insertion or removal from a jack, after which insertion/removal "events" are captured and reported to a network manager. Other examples include the ability to turn LED lights on or off around specific jacks to help guide technicians performing cross-connect work. In general, a well-rounded electronic patch panel system will provide a variety of status and change-oriented reports, and may also be used to sense other systems of importance in managing the physical environment in wiring closets.

Intelligent patch panels. This category of "unconventional" patch panel, as shown in Fig. 2 (in original article), includes devices with all of the attributes of wireless and electronic systems. As its name implies, the intelligent patch panel is fully manageable from a remote centralized station. These support a variety of automated functions including:

  • Centralized on-line control: The ability to make cross-connection changes and assignments from a remote centralized station, thereby eliminating the need to send technicians to wiring closets. This also implies the total elimination of patch cords, since all cross-connections are made through internal electronics.

  • System monitoring and reporting: The ability to activate sensor functions, as in the case of electronic patch panels, along with powerful reporting capabilities for network management.

  • Automated recordkeeping: Fully integrated cable management system that controls moves, adds, or changes and records for full "as-built" documentation reporting capabilities. Systems of this type make heavy use of user-friendly graphical user interfaces (GUIs) as well.

  • Disaster recovery: The ability to withstand power failures using backup power supplies, robust memory systems, and secondary/backup path selection.

  • Security: The ability to password-protect configurations and associated databases is also common to these and all other intelligent systems.

Equipment analogous to intelligent patch panels. In many respects, the concept and functions of intelligent patch panels are very analogous to other forms of switches and intelligent hubs. In the voice arena, every PBX or telephone system out there minimally performs internal cross-connections between stations (extensions) and trunks (phone lines). Even the process of establishing station-to-station connections or multistation/conference calls resembles the same kind of flexible connectivity implied by our definition of intelligent patch panels. In the world of high-speed data networks, intelligent hubs (sometimes referred to as wiring concentrators) also provide dynamic internal cross-connections when used in conjunction with remote centralized management software. Using systems of this type, a network manager can electronically group several network users together in one "logical" network on one day, and on the next, totally redefine the group such that a different mix of users results. This can all be done without having to dispatch technicians to wiring closets.

Performance considerations. In spite of the general appeal of the products discussed here, none of them offer a cure-all from a functional standpoint, and all have their limitations. First of all, any of the products currently in place on the market are media-bound. In other words, they are all either copper-only or fiber-only in makeup. This may represent a drawback in cases where users require multi-media connectivity such as needing to extend copper circuits over long distances where fiber may be the preferred choice.

All of the systems currently on the market also appear to be rather application-bound. In other words, the intended applications seem to be restricted to data-only requirements. This appears to be less the case with the wireless patch panels and more the case with the others. The granularity of treatment required for voice, where for example, 1-pair cross-connections are often required, would appear to be either impractical or cost-prohibitive.

And lastly, even when it comes to data network performance, this technology is still somewhat behind the rest of the industry. If we assume the expectation in the industry is 100-megabit per second (Mbps), or Category 5 UTP, then performance levels are required. Products in each of the three categories roughly break out as shown in the Table (in original article).

What's interesting about this performance analysis is that only the "unconventional" patch panel still relies on "conventional" cross-connection methods rates at the industry-standard level of Category 5 performance. This is not surprising, since Category 5 systems are very sensitive to deviations in crosstalk and attenuation. Unconventional methods of establishing and maintaining circuits appear to have a long way to go before these alternative technologies can stand up to the task of supporting continuous data streams at 100 Mbps. Only one manufacturer of "intelligent" patch panels indicates its products have tested successfully at 100 Mbps. However, they currently hold no certification. This could prove to be problematic in the short run, since all of the industry standards for certification are based on the use of conventional connecting hardware, not unconventional electronic switches.

In any case, the nature of the products described here as electronic patch panels is such that all electronic functionality is essentially nonintrusive. In other words, the key functions of sensing and reporting really do not interfere with or participate in the cross-connections themselves. Certainly the presence of LED lights are external to the connectivity scheme inherent to these devices. Thus, it's no surprise performance for these products is in line with the mainstream of traditional patch panels, and higher than products in the other two categories.

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