However, consider the areas where a phone may be needed but there are no PCs. Keep security in mind here too; while it may be good to offer clients a phone to use in waiting areas or hallways, remember that you are also offering potential attackers a port into your network should a VoIP phone be placed there. The VoIP handsets in some cases are powerful tools which can themselves be used for mischief on the network in the wrong hands so think and plan carefully.
While you are auditing your network, don't forget to factor in the added overhead of the planned VoIP deployment to the network system. If the existing infrastructure is running at 85 percent of capacity now, adding VoIP to this network may not be advisable without overhauling the whole network. And while the network is being overhauled, you may also want to consider adding the ability to run power over Ethernet (PoE) on most if not all network ports -- this enables provision for devices to come in the future as well as to power the VoIP handsets.
As well as considering the network and its quality and capabilities, it may be a better idea to allow for a new network cabling/switching rollout dedicated solely to the VoIP system or to boost the data network infrastructure. While this would definitely be costly in the short term, there would be significant benefits if the system is managed effectively as well as reducing potential stress on the existing data network and enabling the VoIP system to "stand alone" and just interconnect with the rest of the data network at strategic points. This not only provides added redundancy, but also allows for future scalability of each network independent of each other as well as the many obvious security benefits.
If there is no possibility of physically running new cable to a location or you have a lot of employees mobile around the office/factory, consider wireless phones running 802.11x. This is a whole new can of worms that I will stay away from in this particular review.
Managing your network
Managing a VoIP network is very similar to a normal data network system. You manage
- a group of systems (IP handsets),
- on a network system (standard IP based),
- with gateways (between the IP network and the digital/anaglogue communications network)
- and switches with management tools, which facilitate the use of system servers/appliances (for management, logs and voice mail system/messages etc) as well as having
- directory service capabilities and call routing in their basic form, being able to provide names or numbers for addresses that are assigned to systems on the network segment they are managing/controlling.
Another benefit -- providing people use it -- is the ability to show who is in/out of the office and even simply who is on/off the phone, including any number of in-betweens such as in meetings, busy, at lunch, etc. Simply by clicking their status on their IP console, the user can flag to anyone who checks on the entire system their current availability status. This enables people wishing to contact them to leave messages, schedule a call as soon as that person become available, or to seek alternate assistance from someone else if the matter is urgent.