Why is VTSL's Technology Different 

VTSL’s technology is second to none.  We have made significant investment in our infrastructure to ensure that our systems are the most innovative and best engineered on the market.  Below are some of the key elements to our technological advantage.


The core of our telephony offering is Silhouette, an award-winning platform that was designed specifically to address the needs of small to medium sized businesses.  It is a multi-tenanted platform built for purpose. Silhouette platforms are used by service providers in USA, Canada, and Europe supporting almost half a million business users.

Network Infrastructure

VTSL’s network Infrastructure is comprised of two Tier 4 data centres (one in the City of London and one in Docklands) specifically selected because they are connected to separate power grids.  They have the highest level of security, back-up power and environmental control available.  Our Super Micro servers are all duel power, carrier grade specification. We operate 10Gb Arista optical switches, and our core routers are Cisco. VTSL run a high availability storage area network (SAN).  In the event of any system failure we have component level redundancy at each site and a full separate-site replica of our infrastructure.  Each of our data centres is a fully operational network.

Moreover, the VTSL network is engineered to ensure there are no single points of failure. 


VTSL’s data centres are linked with multi-gigabit fibre to create the VTSL cloud.  Within data centres we are connected to the PSTN via multiple Tier 1 carriers.  VTSL is connected to the internet via multi-gigabit connectivity and Tier 1 ISPs. We have multiple internet peering partners, including London Internet Exchange (LINX).  Additionally, VTSL pursues street level diversity for resilient connections to our key telecoms and ISP partners.

Software Development

VTSL’s developers are constantly adding to the eco-system of applications that provide advanced functionality and features to Silhouette.  Most applications are available to our customers via our online web portal.  These include: call recording, call reporting and call centre functionality.  Our development team also work on integrations with third party software including CRM systems and sector-specific applications (i.e. Patient Connect, CardEasy, etc.).


Where possible we pursue a policy of virtualisation of all systems using VMware software.  All of our core systems are virtualised, including Silhouette call processors, NowMessage voicemail servers, OpenLink media servers, Mitel border gateways and Frafos session border controllers.

This policy allows for massive scalability, flexibility and responsiveness.  It is a hugely flexible environment that enables VTSL to adapt to an ever changing technical landscape.

For example, we run multiple instances of Silhouette, giving us the ability to test new software releases or develop new applications with no interference to our production systems.

New Network Layout