Asterisk Voip

Is Asterisk a Good Fit? (Part 2)

…. (Part 1)
Asterisk is distributed as free, open-source software. The only costs involved with Asterisk are hardware, right? Well, maybe not.
As we have been discussing, Asterisk is very flexible. Determining how best to use the flexibility can quickly become a huge time-sink. Compatible handsets are also not free.
The total cost of owning Asterisk can also include downtime.If we choose to support Asterisk on our own, and have to work to try to get Asterisk back up after a failure, there is an opportunity cost involved in the calls we should have received
.This is why we should only choose to support our phone system internally if we have the appropriate resources to back that up.
Total Cost of Ownership (TCO) is not an easy calculation to make. It involves assumptions of how many times it will break, how long it will take us to get it back up and running, and how much consultants will charge us if we need their services.
TCO is only useful when comparing phone systems to each other. The following elements should be included when comparing TCO of multiple phone systems:
  • Procurement Cost: This is the cost to buy the PBX. In the case of Asterisk, it is only the cost of the hardware; other systems will include an element of licensing.
  • Installation Cost: This is the cost to configure and deploy the PBX. Some companies choose to do the deployment in-house; in such instances, there is still a cost, and to enable fair comparisons, it should be included.
  • Licensing Cost (one-time): This is the cost of any one-time licensing fees. Some PBX systems will require a license to perform administration, maintenance, connect to a Primary Rate ISDN line (PRI), etc. In Asterisk, this would include the G.729 licensing cost, if required.
  • Annual Support Cost: This is the estimated cost of ongoing maintenance. Of course some assumptions will have to be made. To keep the comparison fair, the same assumptions should be carried over between vendors.
  • Annual Licensing Cost: Some phone systems will have an annual cost to license the software on the handsets, as well as a license to be able to connect those handsets to the PBX.
When we have created the table, we can calculate the TCO for one year, two years, and so on. We can then evaluate our business and decide what costs we’re willing to incur for our business phone system.
asterisk phone system
Return on Investment
The cost of owning a phone system is only one piece of the Return on Investment (ROI) puzzle. ROI attempts to quantify an expenditure’s effect on the bottom line, usually used to justify a large capital outlay.
  • Just as an example, one phone system that I installed went into an existing business. Its existing phone system had an automated attendant that had the unfortunate habit of hanging up on customers if they pressed the 0 key, or if they didn’t press any key for 5 seconds.
What was the ROI for moving to a new phone system? Not having angry customers who got hung up on is a hard value to calculate. According to one of the owners of the business, that value was infinite. That made the cost of Asterisk very easy to justify!
  • ROI is basically the TCO subtracted from the quantification of the benefit (in money) to the business. So, if we calculated that a new phone system would save $5000 and cost $4000, then the ROI would be $1000.
Another interesting calculation to make, which is also categorized as ROI, is the time for the cost to be recouped. This calculation is one that I find helpful in making a business case for Asterisk.
  • Suppose a phone system costs $5000 to install. Using toll bypass, you can save a net $500 per month. In 10 months, the cost of installing the system will be swallowed up in the savings.
These are simple examples, but Return on Investment can help to justify replacing an existing phone system. By having these numbers prepared before proposing to replace the phone system, we can have a more professional appearance and be more likely to succeed in starting our Asterisk project.
How Much Hardware do I Need to build Asterisk system?
This is probably one of the questions most frequently asked by those who are new to the world of Asterisk. The answer depends largely on what we are going to do with our system.
  • Conversations that bridge between codecs (called transcoding) take the most power to handle. VoIP conversations seem to take a little more processing power than straight Time-Division Multiple-Access (TDM) calls. Having our server run scripts to find information will take more power than if we define everything statically. How many different conversations we have going at a time will affect how much horsepower we need our server to have. As will the features we use.
Do you see the complexity of answering this question? We have to figure out what we are going to use before we can figure out how big a server we will need. That said, there are some good rules of thumb we can start off with.
First, we can run an Asterisk server on a PC with minimum require 1GHz processor with 128MB of memory, 20GB disk and an ethernet adaptor. We are creating a robust phone system. We do not have to pay to license the use of the software, and we do not have to pay per extension. We can go spend some of the money we saved and buy a decently powerful server.
  • As we select the components for our server, we need to remember that we are not building an email server or a web server. We are creating a PBX that people are going to expect to be running all the time. We should select a stable chipset, with an up-to-date BIOS, and match it with other current high quality components. By using high-quality components, we increase the likelihood of ending up with a highly-availability phone system.
asterisk system
  • The most important lesson to keep in mind is that people have grown to depend on phone systems. We should not skimp on hardware as doing so could, in the long run, cost us dearly. With the unique pricing structure of Asterisk, all we will have to pay for is any additional hardware to get increased reliability and capacity.
Along with hardware, the question is often asked “Which distribution of Linux should I use?” If you already have experience with some distribution of Linux, you should be able to make Asterisk work with that distribution. Asterisk is very flexible and has been built with commonly available dependencies, and any distribution of Linux should work. That said, some distributions will require more effort to enable some features such as automatically starting Asterisk when the server boots. Since each distribution treats startup scripts differently, most distributions will require a minor amount of tweaking.
Asterisk is a powerful and flexible framework, based on open-source software. It can be used to create a customized PBX for almost any environment. But it is not always the best choice for reasons we have just explored. We must consider this carefully in order to be confident that Asterisk is the right choice for our business.

Title Post: Is Asterisk a Good Fit? (Part 2)
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