First we need take a look at some of the issues of administering this technology from the perspective of the folks that will actually do the hands-on work.
The technology behind VoIP is fairly simple. With VoIP we use packet-switched data encapsulation (SDE) versus time division multiplex (TDM). This circuit switched telephony has been used since the dawn of time, or at least since the old fashion switch board operators like you might see in an old black and white ''I Love Lucy'' or ''Honeymooners'' episode where they would connect one caller to another by manually plugging the line into a huge wall of sockets.
It will be quite some time before we completely do away with that type of POTS (Plain Old Telephone Service (POTS), Key Telephone System (KTS) and Private Branch Exchange (PBX) switching, all of which have the ability to squeeze multiple phone calls onto a single copper line. For this reason, most businesses will look to integrating VoIP into their existing systems versus totally replacing them. So it becomes important to understand the limitations of traditional telephony and to know where advancements in VoIP technology can make up for the shortfall.
As long as you understand the fundamentals and you have an existing LAN, then you can start experimenting with this technology right away and for little cost since VoIP is simply layered over TCP/IP, so any hub-based or even wireless Ethernet LAN will do to start testing. You will soon learn that speed is the name of the VoIP game so the faster the network, the better the quality of the connection.
VoIP Pros and Cons
When comparing VoIP to standard PBX type phone systems, you soon begin to see some of VoIPs disadvantages.
For starters, when dealing with VoIP in high utilization scenarios, quality of service (QOS) assurances become difficult to deliver, versus dealing with an old fashion PBX system. Quite often, the same scalability characteristics companies find attractive can ultimately be the reason their implementation of the technology initially fails.
High-end VoIP networks such as those in large calling centers or a corporate headquarters with thousands of users, can become so complex that QOS level guarantees become harder to assure versus the traditional circuit switched voice network that has clear and concise capacity restrictions that built into the system and around which quality of service levels can easily be guaranteed and benchmarked.
VoIP does make physical provisioning and installation much easier versus a PBX installation, which requires a network of electrical wires, loops and switches in order to function. A VoIP installation, on the other hand, will use your existing IP network so the logistics of building your VoIP network are largely simplified since the required physical elements are already in place.
The key advantage to standardizing your IP-based network for data, applications, and now VoIP, is that your administrators will have only one network to maintain. This means supporting only a single network cabling system, rather than separate systems, one for voice and one for data. And if you choose to move to WiFi Ethernet then you dont even need most of the cabling. We can compare this scenario to the old school PBX administrators that will still be required to maintain a separate local area cabling network for just the PBX system.