Potential drawbacks to VoIP phone systems
There are two main drawbacks to VoIP phone systems: network demands and potential outages.
Network demands
One challenge to maintaining IP call quality is bandwidth; high quality sound requires a significant amount of bandwidth. Once you move to a VoIP system you will be running all of your business communications over a single network including voice, data, e-mail, and Internet. Some existing networks aren't up to the demands of VoIP and so costly upgrades may be necessary.
Computer networks are designed to handle huge amounts of data efficiently by breaking them into small pieces. Data files and IP voice data both travel along the networks in packets, and packets can move fast or slow depending on the available bandwidth. This variation in speed is not critical for data files, but it is for IP voice packets. If voice packets are not given priority when sharing bandwidth conversations sound distorted, choppy, latent, or drop altogether. The solution is to have quality of service (QoS) routers or switches installed at each location that uses your network for VoIP.
QoS devices give voice data a higher priority as it is trafficked through your network. If there is network congestion, VoIP voice packets are routed through first so call quality does not suffer. QoS applications are built in to some VoIP systems as well as some routers. They can also be purchased separately as upgrades.
Outages
Unlike traditional phone systems (that get set up and basically forgotten), VoIP systems require occasional upgrades and regular maintenance. This means there is the potential for downtime.
VoIP phones are, by definition, network-dependent. To businesses where phone service is absolutely critical, this can be a concern since computer networks can occasionally be brought down by a server crash or other problem. However, a good IT staff can prevent most outages and react quickly when one occurs. Potential outages are one reason for maintaining a mix of digital and VoIP services as it creates a more comfortable level of redundancy. Companies that have backup power systems in place can keep their PBX running, and the digital phone system within the main office will continue to operate even if the data network is unavailable.
