4. Router Platforms
The Linksys WRT54GL is a consumer router offering that broke out from the crowd at least in part because it was running a Linux-based operating system. This meant that it was effectively a cheap hardware platform sufficiently open to allow software developers to enhance its capabilities through aftermarket firmware.
There are a variety of such releases, including Open-WRT, DD-WRT and Tomato. Some, like DD-WRT, started out as open source projects but have evolved into commercial activities in their own right. They in turn have worked to support a variety of hardware platforms.
I am amazed at how often I find this type of software being used, even in small business establishments. I often find that IT staff from considerable companies run such wares in their homes. They seek the complexity of control that they have in their working lives, but on smaller and less costly hardware platforms more appropriate for the home.
This trend was so pronounced that in 2009, NETGEAR, a late comer to this party, introduced products specifically targeted at this open source, 3rd party firmware community. The WNR3500L wireless-N router is the current top-of-line offering.
While all of this is curious and possibly interesting, its application to Asterisk might be limited. However, these router platforms are on the $50-100 range and Asterisk has in fact been ported to this hardware. This makes such little routers a very cheap way to get started playing with Asterisk.
However, they are not without their issues. These devices were built to a task and so are inherently resource limited. That means limited memory, lack of persistent storage beyond on-board flash. They often lack the physical ports that other platforms, like the Sheeva Plug, provide to enhance storage and expansion capabilities. These factors tend to complicate the use of Asterisk if you're not inclined to hack through some solutions on your own.
Yet, those people that I find making use of Asterisk on such hardware are often very committed to what they're doing. They've accomplished something significant getting this little, limited hardware device to run something considerably beyond its original scope. They've added a lot of value along the way.
I would be remiss in leaving these little router platforms out of my overview, but I do feel that they are generally in the domain of the hobbyist / experimentalist. Not something that I'd recommend for a home-based small business.
5. Thin Clients
HP Thin Clients
In most respects, a thin client is simply a small, resource-constrained PC. Their intended purpose is to give an end user a low-cost platform from which to connect to hosted resources on larger server systems. As they are usually not running a major application, they don't need massive amounts of memory or storage. They mostly provide the GUI layer for the end-user.
I was fortunate in that a few years ago someone gifted me a box of HP T5700 thin clients from a scheduling system that was being decommissioned. The T5700 are older models and no longer sold. But there are newer and more capable models available currently. Here are some sample specifications:
|OS:||HPThinPro||Debian Linux (2.6 kernel))||Win XPe|
|Processor||VIA Eden Processor 1.0 GHz||AMD Sempron 2100+, 1 GHz||Transmeta Crusoe TM5800 733 MHz "“ 1.0 GHz|
|Memory:||512 MB DDR2||1 GB DDR2||256 MB DDR266|
|Flash memory:||512 MB||1 GB||256 MB|
|Graphics:||VIA Chrome9 HC3 DX9||ATI Radeon X1250 graphics||ATI Rage XC with 8 MB SDRAM|
|Ports:||4 USB 2.0,
1 microphone in,
|4 USB 2.0,
1 microphone in,
|4 USB 1.1,
1 microphone in,
The thin clients that I have seen come with auto-sensing universal power supplies and typically draw about 10 watts under full load. They boot from internal flash memory that's on an IDE interface. The operating memory is usually one common SODIMM module.
For the earlier T5700 models, HP offered an optional expansion package that's intended to give the thin clients some expandability. The expansion package is a replacement for one side of the case and a PCI riser card. When installed it allows the thin client to accept one PCI expansion card.
I have used the expansion option in several ways;
- To add a second network interface allowing me to use a T5700 as a router
- To add a USB 2.0 card enabling the use of USB storage over faster USB 2.0 ports
- To add internal space allowing the addition of a 2.5" IDE hard drive.
Thin clients are a bit on the pricey side when purchased new. However they are usually available much cheaper on eBay. It's not uncommon to see the T5700 series being offered in the $50-100 range.
If you want to buy them directly from HP, you can often get a bargain by purchasing through the HP SMB Outlet, where I routinely see newer models in the $140-200 range.
Since you will be replacing the OS with your favorite Linux variant, be mindful that you don't need to pay extra for the models that include Windows CE or XP licenses. The SMB Outlet often has models on offer without an OS, which are usually a little cheaper.
There is one thing to bear in mind about older model thin clients; there may be some BIOS limitations. For example, my T5700s will only accept up to 512 MB of memory.
Because these thin client platforms are all based upon x86 processors, you can treat them like a small server. Within the limits of the available CPU and memory they will run Digium's G.729 codec or the Skype-For-Asterisk modules. My own experience is that a T5700 with 1 GHz CPU and 512 MB memory will easily handle four simultaneous G.729 transcodes and was then limited by the number of G.729 licenses I owned at the time.
Given that a typical thin client doesn't have a hard drive, I tend to use them with Asterisk distributions that are built for use in diskless devices, like Astlinux or Askozia PBX.