Advantages of an On-Premises IP-PBX
It uses your LAN
An IP-PBX business phone system will reside on your network using your existing LAN (local area network). The PBX server is only a short distance away, so signalling distance and time (latency) is very short and does not depend on traveling over the Internet and other networks.
Lower operational costs over time
In addition to taking advantage of lower cost VoIP routing, purchasing your own IP-PBX lowers costs over time. When using hosted VoIP the initial costs are most likely lower, but monthly subscription costs are ongoing and higher over time when compared to an IP-PBX. A business owned IP-PBX will usually result in lower averaged monthly operating costs especially for systems with a higher number of users.
Easier to configure and install than proprietary phone systems
Proprietary phone systems can be cumbersome and difficult to navigate around their software to configure and install. An IP-PBX system will be much more familiar to computer savvy people, especially someone who has experience with networks.
the GUI of an IP-PBX will be much more user friendly than traditional PBXs. This allows for easier changes and additions.
Easy to move phones
because phones are IP based, they are like PCs, move them from one connection to another and they find home and connect right back up to the PBX server. No longer are the days when a simple phone move needs to have cross connects changed and phone technicians making a billable service call.
having the ability of receiving and listening to your messages from your Outlook inbox, along with PDFs of faxes increases communication and productivity. Integration with work applications, such a CRM packages can help business performance.
can be added to an existing system and connected through an Internet connection. (Again lower cost, with the IP-phones being the major cost of the hardware needed.)
employees can plug in a compatible IP- Phone at home to their Internet connection and be extension dialling.
Cost savings by connecting to VoIP providers via SIP trunking
Using SIP trunking with an in house IP-PBX can connect to lower cost VoIP providers; reducing phone bills, especially long distance and International calls.
Major companies that have built PBXs are now focused on IP connectivity, but even better are all the upstart companies that are building Asterisk IP-PBXs with lower prices and vendor neutral hardware.