Skype has terminated its partnership with Digium, effectively killing Skype for Asterisk, which integrated Skype's VOIP service with the open source PBX/telephony platform. While some analysts see Microsoft's impending acquisition of Skype as the source of the schism, others argue that Skype has never been an open source supporter, and had already been backing away from the Asterisk product.

Two weeks after Microsoft said it would acquire Skype for $85 billion, the voice-over-IP (VoIP) company has begun cutting its ties with the open source world. Digum, which sponsors the Asterisk project, was the first partner cut loose. After July 26, new Asterisk users will not be able to connect to the Skype network.

Skype decided not to renew its agreement with Digium, according to a May 25 Digium email sent to Asterisk users. The agreement had allowed the Digium-sponsored open source Asterisk telephony system to be integrated with the Skype service, Digium said. Digium is behind most of the work on Asterisk, and sells commercial software and hardware products based on the platform such as its Linux-ready Asterisk Appliance (see below).

Digium's Asterisk Appliance

Skype for Asterisk is said to use some proprietary code from Digium to connect the two products. "It includes proprietary software from Skype that allows Asterisk to join the Skype network as a native client," according to Digium's letter. "Skype has decided not to renew the agreement that permits us to package this proprietary software."

Skype for Asterisk sales and activations will end on July 26, but Skype has promised to continue supporting and maintaining the software for two more years. Skype may extend this time period "at their discretion."

Many businesses and governments around the world rely on Asterisk for its free and flexible PBX software to power their VoIP deployments. The integration with Skype gave access to low-cost voice and video calls without complex integration.

Another open source slap from Microsoft?

Microsoft is expected to launch a hosted version of its Lync unified communications server this summer that will compete directly with Asterisk. Indeed, Digium may have seen this one coming, as its CEO predicted shortly after the $8.53 billion deal was announced on May 13 that Microsoft might "wall-off" Skype from competing products.

Microsoft's tendency toward "notoriously proprietary tactics" will slow the development of Skype as a business tool, Danny Windham, Digium's CEO, wrote in a May 13 company blog. "Microsoft plus Skype equals Microsoft," Windham added.

Or is this just Skype being Skype?

While it may be easy to pin down Skype's decision as yet another example of Microsoft trying to shut down the open source community, Tim Panton, a Skype developer, pointed out on his WordPress blog posting that Skype for Asterisk has been dying slowly for awhile now because of issues with scalability and maintenance. Skype had "hobbled" the product with a number of license restrictions, and the company delayed development, according to Panton.

"Skype probably never envisaged renewing, so when it came due, they pulled the plug," Panton wrote.

Others agree that Skype was already backing away from Asterisk. "I do love a good conspiracy, and it would be great to pin this on Microsoft," wrote Dave Michels, president of Verge1 Consulting, specializing in PBX strategies, in a Pin Drop Soup blog posting. However, Michels noted that it was unlikely Microsoft was calling the shots when the deal hadn't even closed yet.

Michels also pointed out that while Asterisk is open source, Skype is not, so claiming Microsoft will ruin Skype because of its anti-open-source stance is "hypocritical jabberwocky." Skype uses its own clients, its own codecs, its own signaling, and its own firmware licensed to hardware partners, and it does not interface with any other networks or equipment other than basic voice services, added Michels.

"If anything, Skype might teach MS a thing or two about being proprietary," he concluded.

A Gartner analyst agreed that Skype's decision had nothing to do with Microsoft. This is a sign Skype will open up its service to other telephony platforms via Skype Connect, Steve Blood, research vice president and agenda manager at Gartner, told eWEEK.

While Skype for Asterisk was a bit deeper than what Skype Connect (formerly Skype for SIP) offers for other telephony platforms, it's a "stronger business proposition" for Skype to offer more customers Connect than to support a proprietary product for a specific vendor, according to Blood.

"I don't think Skype for Asterisk was compelling enough, nor did it generate enough money for Skype to continue to support it," Blood said. Skype Connect currently works with telephony systems for Avaya, ShoreTel, and Cisco, among others. Digium will be validating Skype Connect next month, according to Blood, so Asterisk customers will continue to have some Skype support.

Prior to the Digium cut-off, the open source community was already nervous about Microsoft's acquisition of Skype and what it might mean for future support for Skype for Linux. However, earlier this month, Microsoft released a statement saying the company would continue to invest and support Skype on non-Microsoft platforms.

Fahmida Rashid is a writer for eWEEK.

This article was originally published on LinuxDevices.com and has been donated to the open source community by QuinStreet Inc. Please visit LinuxToday.com for up-to-date news and articles about Linux and open source.