IP PBX enhances collaboration as employees at different locations can truly feel like they are part of the same organization. Plus, if they are on the company network, the phone calls are free – even if your offices are located thousands of miles apart.

If your remote users connect to the company network via a Virtual Private Network (VPN), VoIP allows them to make phone calls from the road at no extra charge. One salesperson on an extended trip can save hundreds of dollars in cell phone or hotel long-distance charges.

Cost-Savings
First saving comes from managing only a single data network as opposed to a data and voice network. For network administrators, VoIP means they only have one network to maintain instead of two. This allows for streamlined network infrastructure and improved administration

The Move, Add, Change (MAC) process also is greatly simplified, because almost all VoIP systems are configurable through a web interface that can be managed by the administrator. This means lower ongoing costs -- you will not need to call your vendor for every MAC.

IP PBX also saves you on man-power costs. Since multiple offices are seamlessly connected, they can share a single receptionist, auto-attendant, and voice mail system.

Operational Flexibility
With a conventional PBX, separate networks are necessary for voice and data communications. One of the main advantages of an IP PBX is the fact that it employs converged data and voice networks. This means that Internet access, as well as VoIP communications and traditional telephone communications, are all possible using a single line to each user. This provides flexibility as an enterprise grows, and can also reduce long-term operation and maintenance costs.

Easy configuration of IP-PBX services is aided by browser-enabled administration and moving an employee with an IP-PBX is as simple as unplugging a telephone and plugging it in at a new location—as opposed to costly service calls from legacy PBX vendors.

Avoiding Vendor lock-in
In the legacy market, PBX phone system vendors thrive in a world where they could sell proprietary systems, drive customers to single vendor environments, create customer lock-in via proprietary call control and endpoints, and force high margin phone and system deals on to customers.

With open-source telecom systems, companies also avoid getting locked into a relationship with one vendor and don't depend on that vendor to create new features. Instead, any programmer versed in Linux can customize a telephone system to the needs of a particular business.

Network Demands
While all your outbound calls will still be carried by PTCL over its network, you do need a good network infrastructure within your organization as all voice traffic will be carried over your LAN. This means, you shouldn’t be using those over the counter, 1000 Rupees switches if you are serious about your IP PBX performance.

UBM suggests that you introduce the concept of VLAN to optimize the traveling of Voice data over your corporate LAN.

Local IT Staff for Network Support
Unlike regular phone systems that get set up and basically forgotten, VoIP systems require more attention. Like any software application, your VoIP server will require occasional upgrades and maintenance.

Also, regular phones get all the power they need through the phone line, they continue to work if there is a power outage. In contrast, most IP phones need to be plugged into a power source to work. By definition, IP phones are also 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