Reduced Hardware Requirements
In recent years many phone system vendors have produced SIP based PABXs and moved away from phone systems that use hardware modules for phones and trunks.
This has become possible because of the appearance of SIP phones and SIP trunks.
No Need For Specialised Modules
In the past, PABX phones used proprietary digital protocols (not VoIP) and the telephony carriers only supplied trunk services on digital ISDN and analog PSTN connections.
The need for these specialised modules has gone away since phones and trunks can now use VoIP and SIP.
Introduction of Pure IP-PBX Systems
The new VoIP ìPure IPî phone systems are networked based applications like any other application running on a server, which enables them to be in a virtual server environment like VMware and HyperV.
The advantages of virtual machine based infrastructure are well known, but the biggest advantage is that customers do not need to buy dedicated vendor supplied hardware and provide rack space, power, and network connections.
A virtual PABX can be housed in an existing virtual machine host; which already has backup facilities, power and network connections.
Advantages of Hosted PBX
Hosted PABXs with VOIP business phone system Doha Qatar have existed since data centers first appeared, but their use was limited to enterprises that could afford broadband links with high enough capacity to carry the voice and signalling traffic.
In recent years, the price of suitable broadband services has reduced to the point where the cost of the data link is no longer a major barrier. In addition, the price of rack space in data centers has also dropped, which improves the overall cost benefit of a hosted system.
With a hosted PBX, the main switching equipment is not located at the customerís site and in some cases the customer has no ownership of the switching equipment at all.
However, some equipment is still needed on-premises to pass voice traffic between the hosted system and the userís communications devices. In this regard, the main consideration is the type of phone used at the customer premises; if they are using physical desk phones they will need LAN switches that have Power Over Ethernet (PoE) functionality.
But if they are using softphone applications on computers they can use the existing data infrastructure to carry the voice traffic to the computers.
Easy Connectivity with Gateways
The type of carrier trunks available to the customer can be limited by the availability of trunks at the data center. To get around this issue some vendors provide gateway devices that can be located at the customerís office.
A gateway device is a cut down VoIP phone system with hardware that provides interfaces between the VoIP equipment and legacy trunks and analogue phones.
Gateway devices located at the customer site may also provide site survivability if the link to the data center is lost. In site survivability mode the local phones still get basic telephony if the main system is uncontactable.
Another way of providing site survivability is to have the hosted system divert incoming calls to mobile phones. This way of providing site survivability is particularly useful if the hosted system uses SIP trunks to connect to the carrier network, as no gateway equipment is required on the customer sites at all.
Multiple Sites As A Single System
Another advantage of a hosted system is that multiple sites can appear as a single system with a single numbering plan and minimal hardware on each site.
This is great for customers that have many small sites that need to communicate directly with each other. And when the hosted system has the carrier trunks connected directly to it (analogue PSTN, ISDN
or SIP trunks), those trunks are not required at any of the sites, which vastly reduces the cost and
complexity of the network.