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Microsoft Skype for Business Server: Product overview

With its Skype for Business services, Microsoft has shaken up the unified communications market by launching an unconventional platform that's generating significant growth.

Editor's note: This article is part of a buying series on unified communications. The features in this series detail the evolution of UC, its use cases and the important criteria to consider when buying a UC service. The series also compares the top UC products in the market. This article gives an overview of the Microsoft Skype for Business Server.

Microsoft's position as a leader in Gartner's Magic Quadrant for unified communications is no mistake. The Microsoft Skype for Business Server, formerly known as Microsoft Office Communications Server and Lync Server, doesn't require any special introduction.

Millions of people use Skype for Business services on a daily basis for their communication needs, making it a trusted and proven solution. Businesses looking to upgrade their UC services will most likely consider Skype for Business, thanks to Skype's popularity and penetration in the market.

The Microsoft Skype for Business Server is a complete UC platform and approach; however, it's not what we're used to with other UC vendors. For instance, Microsoft does not manufacture its hardware IP PBX systems, such as voice gateways, IP phones or similar systems. Therefore, this solution is completely Windows Server-based, which may make some IT administrators and telecom engineers unhappy.

With a database of thousands of installations, Skype for Business is setting a completely new standard of UC services on a global scale.

The Microsoft Skype for Business Server can support a range of business sizes, including small enterprises with up to 4,000 users at their central site, medium enterprises with up to 80,000 users with multiple remote sites, and large organizations with more than 100,000 users spread across multiple remote sites.

Depending on the size of the enterprise and number of users at headquarters and remote sites, multiple servers are required to ensure proper load balancing and high availability of services.

Setting up servers for internal and external tasks

In its simplest deployment, a Skype business solution would require one Skype for Business Server installed on a Windows 2012 R2 64-bit server that would handle user registration, databases, call routing, instant messaging, presence services and more for internal users. Additionally, the deployment would need one Edge Server to give users Skype for Business Server functionality outside the office for mobile or remote users, while at the same time allowing participation during meetings, IM and other communications with outside users.

If your organization uses Skype, users are likely to feel comfortable with Skype for Business and the learning curve will be minimized.

Redundancy is covered with the installation of multiple on-site Skype for Business servers in an active-active configuration. In this redundant model, users are balanced between the servers. If a server fails, other servers can provide uninterrupted service to users.

In larger-scale deployments, the Skype business server splits its roles into separate servers, creating pools of servers for specific tasks. Organizations can have a pool of front-end servers and back-end servers. The front-end servers handle user authentication and registration, presence information, IM, conferencing and more. Back-end servers are SQL servers providing database services to front-end servers.

Microsoft provides a plethora of documentation on different deployment models supported and technical requirements. This is one of the big advantages with Microsoft-based solutions -- IT departments will find a healthy amount of information that will help them deal with pretty much any problem they encounter.

Capitalizing on consumer Skype, touting ease of use

The Microsoft Skype for Business Server client has a similar interface to the free consumer-based Skype. Contacts, presence status, buttons and icons are the same as the consumer Skype application.

The recent facelift Microsoft gave to its Skype client has made the interface easier to work with and less cluttered. Functions such as Quick Actions buttons have migrated from Lync to the new Skype client, allowing users to access call, instant message, video conference functions and more, with just a few clicks.

Organizations with PBX desk phones can use their phones to place calls to other Skype contacts. From the Skype client, users select the person they want to call and simply initiate the call from within the client. The Skype business client then sends the signal to the Skype for Business server, which in turns signals the PBX to open the user's line and make the call via a desk phone.

With the Skype business client, users can make calls, share files, have voice or video conferences, share desktops, send instant messages, view real-time presence information for other users and much more. The Skype client runs on Windows and Linux operating systems, Android phones, tablets and Apple's iOS.

Connecting Skype for Business with external services

Skype for Business offers a variety of methods to connect enterprises to the rest of the world, including Internet, PSTN/ISDN and telecom providers.

As mentioned earlier, Edge Servers are used primarily to connect an enterprise with the Internet and provide a number of services, including:

  • Access Edge Service: Used for inbound and outbound SIP protocol traffic.
  • Presence and IM Proxy Service: Allows mobile and remote users access to presence/IM through the XMPP Proxy Service.
  • Audio and Video Edge Service: Allows application sharing, audio and video and file transfers for remote or mobile users.
  • Web Conferencing Edge Service: Makes it possible for external users to join meetings hosted on the internal Microsoft Skype for Business Server.

Reverse proxies are another essential component in WAN deployment models. Reverse proxies work with Edge Servers and help external users download meeting content, update clients and devices, download files from Address Book Server, connect to meetings using URLs, and discover front-end servers offering mobility services.

Mediation Server is a Skype for Business component responsible for translating signals between the internal VoIP infrastructure and PSTN network or SIP trunks. The Mediation Server undertakes the important role of media transcoding between phone calls, encrypting and decrypting SRTP on the internal side of the network where the Skype for Business Server resides. The server also handles SIP connections to telecom providers and IP PBXs that act as gateways for the PSTN/ISDN network.

Organizations that need to connect Skype business services with their PSTN/ISDN network need to use the Mediation Server along with an IP PBX gateway. The IP PBX gateway acts as a termination point for the PSTN/ISDN network, and communicates with Skype for Business via the Mediation Server using SIP.

Skype for Business offers a list of certified vendors that have passed their testing requirements by conforming to the specifications provided by Microsoft. This does not mean other non-certified vendors/equipment will not work with Skype for Business -- it just might take more effort and there is no support provided.

The Microsoft Skype for Business Server offers a different approach to UC. With a database of thousands of installations, Skype for Business is setting a completely new standard of UC services on a global scale.

If your organization already uses Skype, then users are likely to feel equally comfortable with Skype for Business and the learning curve will surely be minimized.

Next Steps

See how Skype for Business differs from consumer Skype.

Take a look at the Skype for Business essentials handbook.

Learn about how enterprises reacted to Skype for Business.

Skype for Business for Mac users is ready to test drive.

Dig Deeper on Developing a UC Strategy