Choosing the Right Unified Communications System

Even though email messaging and social media are now well established as business communication tools, they augment rather than replace traditional routes such as telephony. As businesses expand, or their current PBX phone system reaches the end of its useful life, they will need to source a replacement, rather than dumping it altogether.

Traditional ISDN-based PBX systems are still available, but the higher line rental costs are pushing IT managers to consider broadband and ethernet-based VoIP solutions that provide better value for money. As they move forward, the choice of VoIP and SIP trunking also provides increased resilience and flexibility that will allow the system to change as they do.

ISDN vs SIP Trunks

Although major telecoms operators still provide ISDN links the simple truth is that for most businesses of any size this legacy technology is:

  • Too expensive
  • Too limited
  • Too inflexible

SIP trunking is the fast-emerging next generation technology that works over data connections such as standard broadband and ethernet, whilst ISDN requires a special line that costs considerably more. If your business moves premises or you need to expand your telecoms capacity, new ISDN lines need to be installed at considerable cost. Using SIP trunking, you can add almost unlimited capacity in seconds without having the road dug up or incurring set up costs.

Hosted or On-Premise?

SIP trunking is both cheaper and more flexible than ISDN, making it the only sensible choice for your business. The hardest choice is actually whether to choose to maintain an IP-PBX onsite or opt for a cloud hosted solution instead.


Managing and maintaining an on-premise IP-PBX is almost the same as managing an ISDN equivalent. In this scenario your IT or telecoms team may need to:

  • Create and manage new extensions, call groups and perform other day-to-day management tasks
  • Source and install additional hardware as the demand for new extensions increase
  • Configure and deploy handsets to end users
  • Commission new broadband connections to handle increasing call volumes and VoIP traffic

Obviously much of this work could be outsourced to an expert service provider to help reduce running costs somewhat. However, the drawbacks of an onsite PBX include:

  • Day to day management costs associated with keeping the PBX running
  • Additional hardware and licensing costs when extending the system
  • Configuration issues when creating site to site links to create a single, unified telecoms system
  • Much harder to create a service that supports routing of calls to mobile phones outside the workplace
  • Localised disasters could take your entire phone system out of action if the PBX is affected

Cloud-Based Hosted Telephony

For the ultimate in flexible telecoms, many businesses are now turning towards hosted cloud services. From the smallest SME to the largest enterprise, cloud solutions like Horizon from Gamma are increasing in popularity. This is because:

  • There is no need to purchase or install a PBX onsite – all call routing is performed by the Horizon system via the internet
  • In-house support costs are reduced as management of the call routing system is the responsibility of Gamma
  • Additional capacity, such as new extensions, can be added via a web interface, ensuring you always have the capacity you need and you never pay for anything more than that
  • Hosted configuration means that set-up is little more than plugging a VoIP handset into the network, making the system incredibly easy to use
  • Unified communications have become a reality, allowing you to tie mobile phones into the existing telecoms infrastructure. Staff will be able to answer calls wherever they are, transparently extending your office to wherever is needed. VoIP handsets will also make and receive calls anywhere when connected to the internet
  • Calls between VoIP extensions are completely free, regardless of where the callers are located geographically

Making the Choice


ISDN is much more expensive than VoIP over SIP trunks and in terms of ongoing costs, cloud is usually cheaper than on site


Cloud-hosted voice is more adaptable to your changing business needs – you only pay for what you use


The Horizon cloud-based PBX is available any place, any time, perfect for localised disaster recovery scenarios or extending your phone system to cover a new branch office

Ease of Management

Horizon minimises the management burden of IP telephony, creating secondary cost savings over an in-house PBX

To find out more about how Start Communications can assist with any of your business communication services please call us on 01444 719300 or email