Abstract: Hopefully you all saw the news that, during his keynote at this year’s Lync Conference in Las Vegas, Derek Burney gave the first public demonstration of video calling between Lync and Skype! This article describes the improvements and new features, which include Video calling, Enterprise-grade security, and Wide-band Audio with SILK.

Author: Carl Olivier, Principal Program Manager, Skype

Publication date: February 18, 2014

Product version: Lync and Skype

Introduction

I’m the Principal Program Manager for Lync-Skype connectivity v2 and I wanted to share some of the technical improvements we’re delivering with this release, later I’ll describe how customers expect to use v2.

So firstly, what’s under the hood in this new release?

The headline of course is that we just added Video calling between Lync and Skype. This is the next phase of our plan to extend Lync enterprise communications to include the Skype consumer community. And there’s more - Calls will use a common enterprise-class security mechanism, so customers get end-to-end encryption based on well-established enterprise standards like TLS, SRTP , STUN, TURN and ICE.

We’re also improving audio quality by using the SILK codec from Skype - designed specifically for real-time calling over the Internet. SILK has proven to be ideal for mixed enterprise/Internet calling scenarios.

To sum up, Lync-Skype connectivity v2 now includes Video calling, Enterprise-grade security and best-of-breed audio.

Here are the details behind these three enhancements:

Video with H.264 SVC

Scalable Video Coding (SVC) is the ideal codec for accommodating mixed environments, including devices connected over the public Internet as well as mobile devices.

SVC (Scalable Video Coding) is annex G of the baseline Advance Video Coding (AVC) standard H.264 from the joint video team made of ITU and ISO/IEC standards bodies. SVC has been specifically designed to handle the transmission of video over varied network and device environments. The sending system will include different levels for the information transmitted, which handle: frames per second, image size and quality granularity.

Receiving devices can then pick and choose what they take from this transmission in such a way as to optimize the experience on the device/network of the receiver. This approach can deliver an acceptable video quality even when incurring very high packet loss (up to 50%). This is ideal for the increasingly crowded public Internet or over mobile networks.

Enterprise-Grade Security

Another area we’re particularly proud of is an upgrade to the way in which Skype interacts with Lync at the media and media signaling levels. While Skype did use some of the standards for NAT traversal and encryption, enterprise customers wanted more. We’ve listened to the Enterprise security community and are pleased to announce support for industry standard:

  • Transport Layer Security (TLS) for signaling encryption (RFC 5246)
  • Secure RTP (SRTP ) for real time media encryption (RFC 3711)
  • STUN, TURN and ICE for NAT traversal (RFCs 5389, 5766, 5245 respectively)

To expand on this a little bit, one of the challenges with setting up peer-to-peer calls when one or both of the participants are hidden behind corporate or Internet firewalls that use network address translation or NAT, is that the participants in the call can’t see the actual IP addresses of the other party and this gets reflected in the call setup invite messages.

These three technologies (STUN, TURN and ICE) for assisting with NAT traversal issues were already implemented on the Lync side (starting back in the Office Communication Server days) and now Skype supports the same mechanisms for Lync-Skype connectivity.

Enterprise security officers will be familiar with all of these industry standard protocols, and with v2, calls involving Lync and Skype will result in better compliance with their established security policies and therefore better control of the communications on their networks.

Wide-band Audio with SILK

SILK’s wideband codec has consistently outperformed alternatives, delivering higher audio quality across a wide range of network environments including the public Internet and mobile networks. Analysis shows that improved audio quality through the use of wideband and Super wideband codecs correlates to longer calls as described in this post: http://blogs.skype.com/2010/09/28/the-power-of-silk/

We will continues to explore ways to improve call quality, and SILK’s best of breed features such as forward error correction make it an attractive option for calls over non-QoS networks such as the Internet, even when the call is initiated on the corporate network.

We expect the combined impact of video, enterprise security and best-of-breed audio that make up this release to lead to significant opportunities for enterprise customers.

New Opportunities

Given the size and momentum of Skype, this has huge potential benefits for businesses that use Lync or Microsoft Office 365!! This new release paves the way for exciting new communications scenarios for enterprises:

B2C – Businesses have told us that they’re seeking ways to create more immersive relationships with their customers and they anticipate that the addition of video will lead to a new generation of real-time communications experiences.  Without over-promising what we can expect here, it’s certainly true to say that certain industries such as financial services, healthcare and retail are all developing new business models in anticipation of video-enabled platforms like Lync.

B2B – Skype’s global availability means that enterprises with Lync can easily bring on and manage suppliers, partners, and project staff located virtually anywhere and with video such calls are richer more meaningful.

Friends and Family – Possibly most important is the ability for employees using Lync to keep in touch with the people who mean most in their lives – mobile employees can still interact with family members, ‘seeing’ rather than just hearing about important events in their family’s lives, helping responding to urgencies. With Lync-Skype connectivity, employees will be more involved in the day-to-day lives of their loved ones.

Hiring – Enterprises will increase their use of video interviews, firstly during the initial screening process and then onwards through the selection process and follow-up. Skype, with its global reach and platform availability is ideal for this sort of Ad-hoc but also critical communications requirement.

Conclusion

Hopefully you enjoyed reading more about the technologies and motivations behind this v2 release of Lync-Skype connectivity. This release combines Skype’s reach with Lync’s enterprise features and I believe in years to come, we’ll realize how these first steps led the way to a new era of communication between individuals and the organizations they interact with.