Practical VoIP for Business
Nearly every business needs voice communications to talk to people on the outside of the company and often on the inside, as well. While many companies are beginning to branch out into non-traditional voice technologies, such as Skype, for internal use and to some small degree for external use, the bulk of voice communications remains tied to the public switched telephone network (the one that provides traditional telephone numbers.) So for business we will focus on modern technologies for supporting traditional telephony with phone numbers. Over time this channel of communications is expected to diminish as more companies and end users become accepting of alternatives to the phone number system. But for the foreseeable future we need to support the ability to call through the PSTN.
So in this series we are going to focus on the technology and approach to building and supporting voice systems that specifically address connecting to the PSTN. Much of this knowledge crosses over and is applicable to alternative systems such as Skype as well. And there is much grey area as systems, such as Skype, often have bridges to the PSTN available to them making them very viable for business telephony as well, even in the traditional sense.
Many people associate VoIP for business use and for connecting to the PSTN with the infamous SIP protocol and to be certain, SIP is the main player in VoIP but it is very important to understand that SIP is just one of many telephony protocols and is not a requirement for VoIP.
For a business context we will assume that it is necessary to address PSTN connectivity as well as a managed platform such as is provided by a PBX. Not all businesses need or desire these functionalities but enough do that both are generally assumed in a discussion around VoIP and will be assumed here... but at least we take the time to address this context and show that it is only an assumption and not the only case.