Hybrid cloud/on-site PBX deployments best current assurance of quality, reliability
On the rise
Hosted or cloud-based telephony is undoubtedly on the rise. The rise is not yet stratospheric, but the fundamentals are sound.
Adoption is top-down: At the high end of the converged (Internet Protocol or IP-based) PBX market, hosted telephony has made bigger strides than in other segments, according to -TechKnowledge[i]. Enterprise implementations will drive demand.
The foundation market of on-site PBXs is gaining fast: IP is strong in greenfields implementations (new companies or branches) and as replacements of end-of-life analogue systems. Giants like Cisco rule high-end IP PBX sales (growing from 40% SA market share to 69% in two years).
Cloud is perceived as a disruptive model: All vendors, including Cisco, listed cloud-based solutions as a threat in the 14-vendor survey.
Cloud has benefits over on-site (lower cost, central manageability, etc).
It is therefore only a matter of time before cloud succeeds on-site IP PBXs.
Addressing reliability and quality
Nevertheless, the journey to the cloud is not without its challenges. The rising popularity of on-site IP PBXs may represent a strong growth foundation for future cloud deployments, but the very fact of an ‘incumbent’ on-site installation, IP or not, is an inhibitor to immediate uptake of cloud.
Among the main reasons for currently preferring on-site is a lingering uncertainty about VoIP quality and reliability of access links. Service providers are attacking this problem successfully with hybrid setups that combine the advanced functionality and savings of hosted systems with the reliability of ISDN/BRI backup, on the off chance that the broadband link fails. VoIP providers have also had success with tools like ViBE, which provide quality of service.
In addition, the N+1 (redundant) solution architectures employed by leading hosted providers assures ultra-high reliability. Despite hardware failures being a reality of any ICT installation, it is not uncommon for redundant setups to enjoy failure-free operation for years on end.
Another inhibitor to cloud adoption is the reluctance of many customers to upgrade their systems after the 2008/2009 recession; many end-user enterprises are sweating their ageing assets. However, as indicated above, larger customers, greenfields customers and customers whose systems are outmoded are keen to explore the increased productivity, future functionality and cost savings of IP.
Step by step
It may come as a surprise that those who have taken the step of going straight to cloud have not necessarily done so in big bang fashion. It is possible to migrate site by site, as you open new branches, group by group, as different classes of personnel are migrated, or even user by user, as they join the company. Calls are then routed between the cloud PBX and the analogue or on-site IP system via SIP trunking, E1 or other strategies.
As also indicated above, the company in question need not have a wholesale cloud implementation in mind at all. For the sake of site survivability, it is popular to retain a configuration whereby the company makes calls out over a hosted platform, for cost savings and unified communications functionality, whilst having the peace of mind of always having reliable basic calls.
The way ahead
Hybrid providers have the run of the field right now, not just for service assurance, but also as they typically provide managed services, such as access link planning, site planning and failover planning. Many Web-only VoIP providers provision remotely without any direct interaction or site preparation and integration into the telco environment.
Currently, it is only by choosing the right configuration and doing the proper planning that your move to cloud will succeed. But as bandwidth restrictions improve and large cloud implementations, both private and public, become more widely publicised, a wholesale move by a critical mass of companies will become a reality.
 SA PBX Market Report (April 2011)