IP Voice (VoIP or Internet telephony which is almost the same thing) is any one of several technologies that allow you to make phone calls over the Internet instead of over the telephone network. You need a bit more than 100kbps per connection using modern VoIP transmission technologies. This has only made available in businesses broadband network that such technology is already well established in the business world.
In addition, improvements in standards, protocols and underlying hardware and software have also made the required broadband speeds more feasible and have reduced costs to where the decision to move to VoIP is more about the timing and the implementation for a business rather than if it should switch or not.
Typically any VoIP system offers slightly lower operating costs (contrary to advertising claims the cost savings are small) but offers a big step forward in available features and functions. For example, it is now perfectly feasible and cost effective for a 20 person small business to run a call center of its own and to have one system manage main and branch offices and even remote and telecommuting workers.
How it works
There are several protocols and methods for VoIP calls – the commonly use standards are termed SIP and H.323 – but they all have some basic features in common. To the user phone calls are made and handled in the same way as they always have been except that VoIP phones often have more features available from menus and buttons than regular phones.
When a call is dialed, the system takes the phone number, connects over the local network to whatever system is providing service. That system figures out if the call needs to go into the regular phone network and if so switches it to a gateway that connects the call over the regular phone network. If the call can be completed without going over the regular phone network (the number dialed is also a VoIP system) then the provider system will route the call directly, performing protocol translation (to a different kind of VoIP) if needed.
Levels of VoIP Service
Businesses need PBXs for switching, handing extensions and for managing multiple users and numbers over a smaller number of lines in order to be cost effective.
Small businesses typically want more lines, a level of robustness not found in residential phone services and a predictable pricing structure. Quality of service becomes an issue. Not surprisingly, a different set of vendors is typically able to satisfy these needs.
Scaling up again, medium businesses with 100 employees or more, have a different focus for their concerns. Quality of service is important factor, new features come into play including call center features like automatic transfer and queuing. Pricing becomes more critical again and in-house options begin to look attractive now that capital costs can be amortized across so many employees. It is clearly more economically and sensible to bring equipment and services in-house. Precise features become more critical as the need to integrate processes becomes critical to business success.
At every level of these services there is considerable overlap, so a small business provider is likely to be able to satisfy the needs of many medium-sized businesses.
Example of IP Phone System deployment connecting three sites
