What Henkel was trying to fix
According to NTT DATA, Henkel had already swapped an outdated telephone setup for Skype for Business. When that contract ran out, it needed something more suited to a global organisation. Two legacy pain points stand out:
- An SBC at every site. Each location previously needed its own session border controller. This is the box that handles signalling and media when VoIP calls are set up and torn down.
- Too many carriers. Henkel had been negotiating rates with telecom providers country by country, which NTT DATA says made cost optimisation difficult. Consolidating to one provider was an explicit goal.
The stated business problem is a familiar one. If the desk phone, the smartphone and the Teams client all behave as separate voice channels, users end up juggling them. Henkel's Dirk Lehmann, Head of Audio/Video Services, says the traditional desk model is becoming obsolete. He says worldwide coverage, a transparent cost structure and customised services decided it, and that NTT DATA's existing knowledge of Henkel's infrastructure "greatly simplified the migration."
The architecture: not one size fits all
The headline is "cloud telephony", but the detail matters more. NTT DATA says it uses SBCs and Direct Routing in countries where regulations prevent cloud calling. So this is a mixed design, not a single setup applied worldwide.
Microsoft's own documentation explains why that matters. Teams Phone has four PSTN connectivity models: Calling Plans, Operator Connect, Teams Phone Mobile and Direct Routing. Under Direct Routing, organizations connect their own telephony infrastructure to Teams Phone with a supported, customer-provided Session Border Controller. Microsoft's PSTN guidance adds that the SBC can be procured and managed by the customer, an integrator, or a Direct-Routing-as-a-Service provider. Microsoft also says organisations can combine connectivity types across users, regions and requirements. For instance, it suggests Direct Routing for workers in remote regions.
A caution on reading the case study: it does not say which countries use which model, or how many sites rely on SBCs. It would be wrong to assume Henkel uses Direct Routing everywhere.
Legacy systems stay connected
NTT DATA says it built a hybrid approach so traditional systems can connect to the cloud solution. Its examples are any fax solutions still in use and emergency systems in the factories. This is probably the most realistic part of the story. Faxes and plant emergency phones are the sort of thing that outlives three CIOs and two rebrandings.
The case study does not say how these systems connect, which sites keep them, or how emergency calls are routed and kept resilient. Anyone planning something similar should treat those as open design questions, not solved ones.
Cost, dashboard and operations
NTT DATA attributes better rates to the economies of scale of its Tier 1 network. It says Henkel can pick rates to suit different calling patterns. It also says a central dashboard shows usage data, which can be used to assign calling plans. The dashboard can also control call options, add users and change settings.
Operationally, Henkel follows an outsourcing strategy for key IT infrastructure, with in-house experts working alongside outside partners. For telephony, it now gets 24x7 service, which NTT DATA says would be very costly to run in-house.
The evidence has clear limits:
- There are no prices, savings percentages, call volumes or ROI figures.
- The claims of higher employee satisfaction and productivity, and of a "rapid return on investment", come with no survey data or baseline.
- The 24x7 service has no stated SLA, response times or scope.
These are the provider's claims about its own work, quoted alongside a customer endorsement. They are not independently measured results.
The Operator Connect hint
The case study says lower costs let Henkel "look at leveraging Operator Connect in the future". That is not an announcement that Henkel has adopted it. Microsoft describes Operator Connect as a model where a certified operator provides the PSTN service and you manage users and numbers in the Teams admin center. The case study's framing is that it would consolidate carriers and keep cost visible in the dashboard. In Microsoft's model, Direct Routing needs an SBC. Operator Connect does not need one, because the operator has already completed the integration. Microsoft also says you can mix the two over time, so a future move would not have to be all-or-nothing.
Practical takeaways for IT admins
The case study is promotional, but the design lessons hold up against Microsoft's guidance:
- Plan per country, not per company. Regulation can decide whether cloud calling is even allowed. Check each country's constraints before committing to one model.
- Inventory the odd stuff first. Fax lines, analogue devices and emergency or safety phones are where telephony migrations tend to stall.
- Decide who owns the SBC. Microsoft's documentation allows customer, integrator or DRaaS ownership. That choice shapes your support and SLA model.
- Ask for numbers. Before copying the cost story, get rate cards, SLAs and emergency-calling details in writing. This case study doesn't supply them.
- Keep options open. Microsoft supports multiple PSTN connectivity types in one tenant, so you can start with one and add another later.
The bottom line
Henkel's deployment shows that large-scale Teams telephony often combines carrier-provided cloud calling, Direct Routing where regulation requires it, and bridges to legacy equipment. NTT DATA's case study is useful for those architectural details. Its claims about cost, productivity and ROI are unquantified marketing statements, and readers should weigh them that way.