Soekris computers are extremely elegant SBC devices.The advantages of using a Soekris box include:
■ Small form factor
■ Lightweight
■ Low power consumption
■ No fans, drives, or other moving parts
■ Ultra-quiet and reliable
In an abstract sense, a Soekris box functions just like a regular 486 PC. However, a regular PC would be difficult to mount in a weatherproof outdoor enclosure. A standard PC would also be more likely to require maintenance because of the power supply, hard drive, and other moving parts. Using a Soekris box is a great way to deploy an AP. In this chapter we’ll tell you more about some of the hardware specifications for the Soekris line. In Chapter 6, “Wireless Operating Systems,” you’ll learn how to install m0n0wall and Pebble on these boxes.
N
OTEVarious versions of Linux, OpenBSD, FreeBSD, NetBSD, and others can be installed on Soekris hardware, which is designed specifically for running open source software.
net4501
Originally, many Soekris devices were used as small, portable firewall systems.The net4501-30 is based on a 486-compatible CPU (an AMD ElanSC520) running at 133 MHz. It includes 64 MB RAM, three Ethernet ports, two serial (console) ports, a Compact Flash slot, one Mini-PCI slot, and a 3.3V
Figure 4.12 net4501 without a Case
PCI slot.The size of the board (without case) is a mere 4.85” x 5.7” and supports an operating tem- perature of 0–60˚C. Figure 4.12 shows a photo of a net4501 without a case. Figure 4.13 shows a photo of a net4501 in a case, and Figure 4.14 shows a net4501 without a cover.
net4511
The net4511-30 is also based on a 486-compatible CPU (an AMD ElanSC520), but it operates at 100 MHz. It includes 64 MB RAM, two Ethernet ports, one serial (console) port, a Compact Flash slot, one Mini-PCI slot, and one PCMCIA slot.The net4511 supports Power over Ethernet (PoE) using the IEEE 802.3af standard.
The size of the net4511 board (not including the case) is a mere 6.7” x 5.7” and supports an operating temperature range of 0–60˚C.
Figure 4.13 net4501 in a Case
Figure 4.14 net4501 Without a Cover
N
OTE: P
OWER OVERE
THERNETWhen you set up an AP, there are generally two interfaces that need to be connected to the AP. First, you need to have an Ethernet cable to deliver the bandwidth and transfer the data.
Second, you need to provide power to the device. The idea of Power over Ethernet (PoE) is simply to utilize the unused wires in a Cat5 cable to provide low-voltage power over the Ethernet cable. It turns out that a Cat5 cable has eight wires, and only four of them are used to provide data. (Note that Gigabit Ethernet does use all eight wires and therefore is not PoE compatible.) The IEEE 802.3af standard defines how to provide power over the unused wires. The net result: fewer cables!
In addition, using PoE, you can simplify your AP deployments and lower your implemen- tation costs. By supplying power over the existing Cat5 cable, you also get more flexibility in terms of AP placement. Now you can put your AP anywhere you like, not just in places where a power outlet is available. This is particularly important when you are mounting APs on a rooftop, where power outlets might not be readily available!
Although it is possible to build your own homebrew PoE devices (www.nycwireless.net/
poe), we highly recommend using a commercial version for safety and reliability. Many ven- dors offer PoE injectors (to introduce power into the Cat5) and splitters (to extract power from the Cat5). Note that sometimes splitters are also referred to as tapsor pickers. If your AP supports PoE directly, you just need to purchase an injector. If your AP does not support PoE (and only accepts power via DC), you will need both an injector and a splitter.
net4521
The net4521-30 is very similar to the net4511 except that the net4521 has 2 PCMCIA slots instead of one.To accommodate the second PCMCIA slot, the board is slightly larger (but still very small), measuring 9.2” x 5.7”. It also sports a slightly faster CPU, clocking in at 133 MHz. Figure 4.15 shows a net4521 board.
Figure 4.15 net4521 Board
net4526
With the growing popularity of using Soekris devices as APs, Soren Soekris (the engineer who cre- ated these wonderful devices) developed a new product, the net4526, that hit a sweet spot for wireless applications.Two models are available: the net4526-20 and the net4526-30.The net4526-20 has a 100 MHz CPU (AMD ElanSC520), 32 MB of RAM, and 16 MB of on-board Compact Flash.The net4526-30 has a 133 MHz CPU (AMD ElanSC520), 64 MB of RAM, and 64 MB of on-board Compact Flash. Both models feature one Ethernet port, one serial (console) port, two Mini-PCI slots, and 802.3af PoE support. Amazingly, the net4526 board measures a tiny 4.0” x 5.2”! Like other models, the net4526 also has an operating temperature range of 0–60˚C. As the Mini-PCI interface grows in popularity for 802.11 cards, this device is ideal for use as a wireless router. Keep in mind that the net4526 does not include a Compact Flash slot (the CF memory is built into the board).
Therefore, be sure to select the model with enough CF memory for your application.The advantage of integrated CF memory is that you don’t need to spend extra money for a CF card, and it allows the board size to be slightly smaller.The disadvantage of integrated CF memory is that it is difficult to increase available CF memory down the road. Figure 4.16 shows the net4526 board.
net4801
Although it is not typically used as a wireless device, we include the net4801 in this chapter for the sake of completeness and because it is such a unique and interesting product.The net4801 is more of a midrange board, since it boasts a powerful CPU (a 266 MHz 586-class NSC SC1100) and is much more powerful than necessary for basic Wi-Fi applications. It also has 128 MB of RAM, three Figure 4.16 net4526 Board
connector (for adding a hard drive), a Mini-PCI slot, and a 3.3V PCI slot.That is an amazing amount of power for a board measuring 5.2” x 5.7”, with an operating temperature range of 0–60˚C.
Although it is clearly overkill for making a simple AP, this device is ideal as a communications appli- ance for other needs, such as a faster firewall, router, caching server, etc.
Soekris Accessories
Soekris conveniently offers packages for its SBC products.You can purchase them as standalone boards or as a package with the matching green case. Power supplies are also sold separately; you can choose between standard AC “wall wort” (adapter) options or 802.3af compliant PoE options. Soekris also sells PCI and Mini-PCI hardware accelerator encryption cards.The cards work perfectly as VPN accelerators or for scenarios where AES encryption is required.The vpn1401 (PCI) and vpn1411 (mini-PCI) support throughput of up to 250 Mbps. For more information, visit www.soekris.com.
Figure 4.17 shows the vpn1401; Figure 4.18 shows the vpn1411.
Figure 4.17 vpn1401
N
EED TOK
NOW… M
ETRIXC
OMMUNICATIONSIf you’re looking for a quick and easy way to deploy a Soekris device in an outdoor enclo- sure, a wonderful solution has been created by Metrix Communications. Its package inte- grates Soekris devices (a net4526) with a NEMA 4x weatherproof outdoor box. With Metrix, you now have a one-stop shop for all your outdoor AP kit needs! For more information, visit www.metrix.net.