Multi Site – IP Telephony


Simple Requirement – can we provide a cost effective telephone system across 12 international sites, and 300 users? – no problem at all.


Key points

  • Large number of existing PSTN Lines.
  • High Call Volume.
  • Call centre and sales lines not to be affected.
  • Variety of handsets required, from standard office phones, to Rugged for Workshops.
  • Multicell DECT (Roaming Cordless)
  • Door entry to be included.


With many of the sites open to the public, we needed to make sure that the deployment could be staged, and that it could be carried out with a seamless service switchover. Using a set of loan PSTN Gateways we could migrate lines from old to new, and deploy handsets to desks is a timely, calm and and structured manner. A variety of areas needed to be provided for, customer service, and reception areas needed a standard office phone, some needed a headset and a soft phone, some would like both. Workshops and transport area needed a rugged, dependable, DECT phone that could withstand the knocks and drops.

Cost was a driver for the switch to SIP. If we could remove the PSTN Lines a dramatic cost saving could be achieved. “Monthly maintenance” on the legacy system, was expensive, not required, and virtually never used. Connectivity was already provided for Internet access, so why not use it for telephony too? There was to be a consolidation of assets and sites – some were to be merged, and some expanded. the solution would need to be flexible and scalable. Reception and service managers needed a console and an overview of the entire system, who was in, who was busy, and who was talking to who, with presence advertised across sites.

Solution: Outcomes

We deployed a centralised 3CX solution to head office, and on their existing server system. this allowed us to back it up, and additionally provide a second instance for instantaneous failover in the event of a server outage. In a smooth and timely fashion the PSTN Lines were migrated to our SIP platform, handsets were deployed and queues and ring groups created. Call routing was developed and users trained on the new facilities as they were introduced, finetuning call patterns to meet the requirement.

Costs were reduced across the board, by the removal of Maintenance, PSTN & ISDN Lines, and migration to SIP trunks. The costly maintenance was removed from the monthly cycle, and replaced with a servicing plan, that was done, as required, and charged accordingly. the trend is that after a short time, all changes to routing and ringing requirements are set and no further changes are required. So why pay for the support that you don’t use….

Once finalised, a fully functional,  and fully managed system was deployed. The capital costs were recovered within 9 months based on the previous line rental, and subsequently ongoing monthly costs were reduced by over 70%..


In Summary – How to reduce a phone system cost by £45,000.
Call minutes per month
Reduction in operating costs
User end points
International Sites