UC adoption boosting enterprise SIP trunking

SIP trunking continues to make inroads into the telephony market, driven strongly by enterprise unified communications (UC) adoption. As a native IP communications technology, SIP trunks allow enterprises to connect UC systems directly to telephony network without the need for gateways.

According to an October 2015 report from analyst IHS, SIP trunks grew 35 percent in the first half of 2015 over the same period a year earlier. It said that the number of worldwide SIP trunks stood at 17.6 million at the end of 1H 2015, and that much of this has come from larger enterprises that are deploying UC.

“The SIP trunking market is on track to top $5 billion in 2015, with the majority of sales coming from North America,” said Diane Myers, research director for VoIP, UC and IMS at IHS. “We look for continued strong worldwide growth over the next five years and project the market to reach $8.5 billion in 2019.”

SIP trunking also allows enterprises to centralize their telephony trunks rather than needing a separate local ISDN trunk with a gateway at every site. This approach reflects the centralization strategy that many enterprises are adopting for unified communications, both for on-premise (in the enterprise data center) and cloud approaches.  

In fact unified communications as a service (UCaaS) is gaining significant traction worldwide. A separate report from IHS found that worldwide cloud-based UC and IP-PBX seats grew almost 30 percent in the first half of 2015, compared to a year earlier. “Across all regions there’s been strong demand for hosted services, and we are forecasting a 20-percent-plus increase in seats in every region in 2015,” said IHS’ Myers.

Helping build the business case for UC

SIP trunking can also play a significant role in building the business case for a full UC transformation. Organizations can make savings of up to 50% in their telephony costs in three key areas by making the switch – which can help fund a UC transformation project. 

The first area of savings is usage costs, which can be cut by up to 99% for some organizations. This is because they can make better benefit of both their existing data network and access more favorable rates. The second is simplified infrastructure, because SIP trunking allows organizations to eliminate the number of connections, gateways and providers they have. Third is better visibility and cost management by centralizing telephony contracts.


Organizations also need to take interoperability into account when considering SIP trunking and UC deployment. Although SIP is a standard, interoperability between all different parts of the UC infrastructure is not necessarily guaranteed. This complex situation is exacerbated when UC vendors update their software, which could potentially cause issues with another piece of the infrastructure. 

Testing is a simple way to prevent problems, and all equipment deployed on the network needs to be thoroughly tested before being deployed. This includes all IP-PBXs, end-points and edge devices.

Anticipating the ISDN switch off

Just as the transition from TDM PBX to IP-based UC is a generational change in enterprise telephony, so carriers are also switching over to an all-IP network with SIP trunking. In fact over the next decade service providers in Europe are turning off their ISDN networks and migrating customers over to SIP trunk.

While this is a great technological move for enterprises using UC, organizations need to think more strategically about their switch to SIP trunking. Simply replacing an ISDN trunk with a SIP trunk, but keeping the same network architecture and providers, doesn’t allow them to take advantage of many of the benefits it provides. A much better approach is to reduce the number of service providers and centralize as much as possible to reduce operational complexity and management costs.

Eight benefits of UC and SIP trunking

SIP trunking and UC complement each other perfectly, and here are eight benefits that the synergy between the two technologies provides.

  1. Powerful ROI: SIP trunking can generate significant savings that can help build a strong UC business case.
  2. Simplified infrastructure: Centralized UC and SIP trunking simplifies UC design, and limits hardware deployment and maintenance costs.
  3. Beyond voice: Fully-converged SIP trunks can carry all communications channels, such as video, without the need for additional infrastructure.
  4. Mobility: SIP trunks allow organizations to fully embrace mobility and significantly reduce the cost of mobile calls.
  5. Any device: SIP trunks give employees the ability to collaborate anywhere regardless of their device and current network access.
  6. Flexibility: Unlike ISDN, which comes in blocks of 30 channels, SIP provides much more flexibility to scale up or down to meet changing needs.
  7. Resilient communications: Switch between trunks across different sites in case of any disruption.
  8. Cloud integration: Integrate communications functionality seamlessly into software-as-a-service (SaaS) applications hosted in your providers’ data center. 

Orange Business is a recognized market leader in SIP trunking and provides best-of-breed UCC tools. We can help you with your SIP trunking and UC transformation every step of the way. Read our paper on UC and SIP trunking here, our blog on the ISDN switch-off here and browse to our campaign page to find out more.


Jean-Sébastien Pegon

Jean-Sébastien is Business Developer for Unified Communications Services within Orange Business focusing on transversal, indirect and complex deals. Since 15 years, in the telecom industry, Jean-Sébastien has been worked in various roles such as mobile and broadband network rollout, service and product management.