Six burning VoIP questions

1. Can I trust Microsoft with VoIP?

There is plenty of uncertainty in the corporate VoIP arena, as reflected in a recent rash of consolidations and private-equity buyouts in the market. One thing users can be plenty sure of is Microsoft's intent to become a large player in corporate IP telephony and messaging.

However, some users and industry observers question whether Microsoftserver technology has the mettle for handling the real-time load and reliability requirements of corporate telephony traffic and applications. Others say the move will help accelerate the use of converged messaging and productivity applications such as presence, Web conferencing and chat.

Well known by now, the centerpiece to Microsoft's VoIP bid is Office Communications Server 2007, a real-time collaboration server which has elicited much buzz and controversy in the industry, for a product not even available for purchase yet. (The server, which is the successor to Live Communication Server 2005, is in a public beta, and is expected for general release later this year.)

"We believe, over time, [enterprise voice networks] can be totally based on Office Communications Server," said Gurdeep Singh Pall, corporate vice president of Microsoft's Unified Communications Group, in an interview earlier this year at the VoiceCon show, where Microsoft launched OCS 2007's public beta. "For now, we also want to help customers . . . who are saying, 'can I trust my voice [network] entirely to Microsoft?'"

OCS, under the hood

As with any commercial VoIP systems, such Avaya, Cisco, Nortel or Siemens, customers will be buying into proprietary Microsoft protocols and technologies if plans are made to rely heavily OCS 2007.

Microsoft is deviating from the industry standard practice of using ITU codecs for voice traffic compression and transmission - mainly, the G.711, G.722 and G.729 codecs.

"We've made several investments in our own audio and video codecs," says Paul Duffy, group product manager at Microsoft for OCS 2007.

Microsoft says part of the value in its own codecs is the ability to compensate for congested or low-bandwidth connections - such as teleworkers' dial-up lines, or broadband links without QoS. Duffy says the OCS VoIP codecs include technology that can repair poor-quality VoIP transmissions. This is done with software that compensates for packetized bits that may be lost from one end to the other during a VoIP conversation. The Microsoft codecs, working with client software on either end, injects signals and tones into the voice stream, which make the calls sound better than standard VoIP calls made over jittery links, the company says.

Additionally, Microsoft uses extensions to standard Session Initiation Protocol (SIP), which allows for more flexibility in the types of connections that clients can make among each other. (OCS supports voice, video, IM and presence across an array of devices, such as IP phones, and Microsoft Office Communicator software on PCs, cell phones and PDAs.)

OCS will also require a separate layer of server infrastructure, called Mediation Servers, in order to communicate with VoIP endpoints using ITU-standard codecs and IETF-standard SIP. These servers act as translators between an OCS 2007 server and the endpoints, as well as a gateway between an OCS server and other VoIP/public switched telephone network (PSTN) gateway hardware. Users considering a centralized deployment of OCS to support remote sites would have to install a Mediation Server in each location in order to support standard endpoints and for making PSTN calls. Microsoft recommends a full Windows 2003 server (minimum of dual-3.2GHz processors with 2GB memory) for running the Mediation Server software, as well as SQL Server 2005.

OCS and the fifth "9"

Then there is the reliability issue. For years, VoIP vendors have moved away from Microsoft's Windows Server as a platform for hosting IP PBX applications. Avaya, Siemens and Mitel run their call servers on Linux. Nortel's Communication Server 1000 runs on the real-time VXWorks operating system (used in military and NASA applications). 3Com's VCX platform runs on Sun Solaris.

Industry observers and vendors say the move away from Windows to other platforms to host VoIP was based on customer concerns about the stability of Windows systems, and the frequent software patching and updating required on the servers. Cisco's CallManager IP PBX, long based on a Microsoft server, was ported last year to Linux as an "appliance-like" system, requiring minimal patching and operating system tinkering, the company says. (Cisco still sells and supports CallManager, now called Unified Communications Manager, on Windows.)

With all this as background, some views on Microsoft's ambitions in enterprise VoIP are skeptical.

"I can see it now," wrote one Network World reader in an online forum about Microsoft OCS 2007. "'Everyone, please get off the phone, we have to apply a bug fix'."

A major move Microsoft made a year ago to convince enterprises that Microsoft can handle corporate VoIP is the company's partnership with Nortel. The two vendors' Innovative Communications Alliance involves shared R&D, marketing, sales and support resources over a four-year span.

"We're dedicated to earning the confidence of all customers" when it comes to OCS reliability, said Jeff Raikes, president of the Microsoft Business Division, during a presentation earlier this year. He equates Microsoft's entry into enterprise VoIP with the company's emergence in mission-critical data center serving. "We're not new to this position in the area of critical communications." He pointed out that the Nasdaq stock market runs on Windows and SQL server, and in upwards of 10 million Cisco IP phones are tied into Windows servers running Cisco's CallManager platform.

"We want to work closely with partners such as Nortel to help power telephony in our software."

Users of both Microsoft and Nortel technologies say this is a good development.

"From what I've seen, it should be positive," says Joanne Kossuth, CIO at Olin College of Engineering in Needham, Mass., which runs a Nortel-based VoIP network, and Microsoft Exchange messaging servers.

The college is beta testing OCS 2007 and could roll out services to the school next year. Kossuth says integration of presence, federated IM and conferencing into Microsoft Outlook, with Nortel call control systems on the backend, will be easier to roll out and manage.

"Now you're going to be able to add capabilities without having to add new staff and skill sets to handle that capability," she says. This has been a concern to Kossuth as she has explored such applications in the past.

As for system reliability, OCS 2007 could only gain from closer integration with Nortel technology.

"In my work with Nortel, I've seen them as a company that engineers products at 150%," she says. "They don't go to market with something unless it's more than ready. Microsoft doesn't necessarily have the same reputation. So I'm thinking that there will be some complementary things there. . . . Maybe together, they'll deliver products that are 100