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Microsoft Exchange Online UM drops third-party PBX support

Some Microsoft customers must quickly re-evaluate their UC strategy after the vendor announced its intent to end third-party PBX support for Exchange Online Unified Messaging in 2018.

Microsoft will end third-party PBX support for Exchange Online Unified Messaging in July 2018, leaving affected organizations less than a year to migrate completely to Skype for Business or find another third-party service.

"I would anticipate quite a few long days for IT admins, as well as more than a few professional services contracts being signed to cope with the changes," said Michael Brandenburg, an analyst at Frost & Sullivan in San Antonio, about Microsoft's decision.

According to Microsoft's announcement, the vendor is retiring its session border controllers (SBCs) and ending third-party PBX support for Exchange Online UM in favor of standard Exchange and Skype for Business protocols to provide higher quality of service for voicemail.

Organizations unaffected by change are those that connect to Exchange Online UM through Skype for Business on premises or a third-party voicemail with Microsoft's APIs, as well as all forms of on-premises Exchange Server UM.

Brandenburg said the change could be motivated by bandwidth and quality-of-service concerns.

"SIP [Session Initiation Protocol] interoperability has been an ongoing challenge for service providers and vendors," he said. "It's not a big leap to suggest that supporting a high-quality unified messaging service at such scale as Office 365 has become untenable for Microsoft."

For organizations affected by the announcement, Microsoft offered four migration options:

  • A complete migration to Office 365 Cloud PBX;
  • A complete migration to Skype for Business Server Enterprise Voice on premises;
  • For those organizations with a mixed deployment of a third-party PBX and Skype for Business, the use of Exchange Online UM through a Microsoft partner, such as TE-SYSTEMS, to connect to Skype for Business server; and
  • For companies with no Skype for Business deployment or for whom the first three options are not appropriate, Microsoft recommended deploying a third-party voicemail service.

Short deadline creates migration pressure

Microsoft said the announcement affects a small number of customers. Those customers, however, tend to be larger organizations with a number of SBCs, according to Jeff Guillet, founder of IT consulting firm EXPTA Consulting in Pacifica, Calif.

"Once customers settle on a connectivity solution, they continue to invest and expand upon it," he said in a blog.

With less than a year to transfer services, Brandenburg said the difficulty organizations will face as they migrate will be tied to their unified communications (UC) strategy.

Organizations that are already on a migration path to Skype for Business, but still have third-party PBX and UC platforms in place, will have to accelerate their migration plans, he said.

"The biggest challenge will be for those organizations that have committed to a heterogeneous environment," Brandenburg said. "These organizations will have to seek out third-party solutions that are compatible with Microsoft's API."

A migration could be rife with complications for organizations. Those that have to replace their existing PBXs more rapidly than planned will face accelerated deployment and user training schedules. Customers planning to deploy third-party services to maintain integration with Exchange Online UM could face software and user-facing issues, as IT will have an additional service to maintain and support, Brandenburg said.

"Forcing customers to plan for and deploy all new phone systems, SBC solutions or voicemail solutions in one year is asking a lot, especially for the size of customer they're affecting," Guillet said.

The announcement also casts doubts over whether Microsoft and other UC vendors can be trusted to support hybrid UC environments, Brandenburg said.

Opportunities for partners

Third-party unified messaging vendors, such as AVST, are offering third-party PBX support for Exchange Online UM. It's possible other Microsoft partners, such as SBC vendors, could build specific connections to alleviate the need for organizations to bring in another vendor, he said.

The announcement also creates an opportunity for UC vendors that already maintain interoperability with the Skype for Business desktop client. Brandenburg said there's nothing preventing these providers from "coming to the aid of their customers" by natively supporting Exchange Online UM through Microsoft APIs.

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