Asterisk gives us the ability to use the Internet Protocol (IP) for phone calls, in tandem with more traditional telephone technologies.
Choosing to use Asterisk does not mean that we can use only Voice over Internet Protocol (VoIP) for calls. In fact, many installations of Asterisk do not use it at all. But each of those systems has the ability to add Voice over IP easily, any time, and with no additional cost.
Most companies have two networks—one for telephones and the other for computers. What if we could merge these two networks? What would the savings be? The biggest savings are realized by reducing the administrative burden for Information Technology staff. We can now have a few experts on computing and networking. As telephony will run on a computer and over our IP network, the same core knowledge will empower our staff to handle the phone system.
We will also realize benefits from decreased equipment purchasing in the long run. Computer equipments get progressively cheaper while proprietary phone systems seem to remain nearly constant in price. Therefore, we may expect the cost for network switches, routers, and other data network equipments to continue to decrease in price.
In most current phone systems, extensions can only be as far away as the maximum cabling length permitted by the telephone system manufacturer. While this seems perfectly reasonable, sometimes we would like it not to be so. When using VoIP we can have multiple users using the same Asterisk service from a variety of locations. We can have users in the local office using PSTN phones or IP phones, we can have remote VoIP users, we can even have entire Asterisk systems operated and run separately but with integrated routing.
One way to slash overhead cost is to reduce the amount of office space required. Many businesses use telecommuting for this purpose. This often creates a problem—which number do we use to reach a telecommuter? Imagine the flexibility if telecommuting employees could simply use the same extension when at home as when in the office or even when using their mobile.
VoIP allows us to have an extension anywhere we have a reasonably fast Internet connection. This means employees can have an extension on the phone system at home if they have a broadband connection. Therefore, they will have access to all of the services provided in the office, such as voicemail, long distance calling, and dialing other employees by extension.
Just as we can bring employees into the PBX from their homes, we can do the same for remote offices. In this way, employees at multiple locations can have consistent features accessed exactly the same way, helping to ease the burden of training employees.
But this is not all that VoIP can give us. We can use an Asterisk server in each office and link them. This means each office can have its own local lines, but office-to-office communications are tunneled over the Internet. The savings to be realized by avoiding call tolls can be significant. But there's more.
Once we have our offices linked in such a way, we can handle calls seamlessly, irrespective of which office the employees are in. For instance, if a customer calls Office A to ask about their account, and the accounting department is in Office B, we simply transfer the call to the appropriate person in the other office. We don't have to care about where that other office is. As long as they have a reliable Internet connection, they don't even have to be in the same country.
We can route calls based on cost. If it is more cost effective, we can send our calls to another office, where the remote Asterisk server will then connect them with the regular phone network. This is commonly referred to as toll bypass.
Another benefit of linking our phone systems together is that we can route calls based on time. Imagine we have two offices in different time zones. Each office will probably be open at different times. In order to handle our customers effectively, we can transfer calls from a closed office to the one that is open. Again, as we are using an Internet connection to link the offices, there is no additional expense involved in doing so.
By linking our offices together using VoIP, we can increase our customer service while decreasing our expenses—a true win-win situation.
The existence of all these options doesn't necessarily mean we should be using them. With the versatility of Asterisk, we may use or ignore options as it suits our requirements. If we were to use every single line type and feature that Asterisk supports, it could lead to a very complicated and difficult-to-administer system. We should choose the subset that fits our requirements and would function well within our current communications setup.