Skype for Business

Skype for Business, formerly known as Microsoft Lync Server, is a unified communications (UC) platform that integrates common channels of business communication and online meetings, including instant messaging (IM), presence, voice over IP (VoIP), voicemail, file transfers, video conferencing, web conferencing and Email.

Skype for Business can be deployed on premises, in the cloud or as a hybrid service. Clients can run on Windows operating systems, Android phones and tablets and Apple iOS devices. The Skype for Business client can also be configured in a Lync Server 2013 environment. The platform is sometimes referred to as S4B, SFB, SfB and Skype4B.

It can be licensed as a stand-alone product or as part of the Office 365 application suite. It is available as an on-premises server, known as Skype for Business Server, or a cloud-based service, known as Skype for Business Online.

Microsoft Teams is cloud-based collaboration software that has similar capabilities to Skype for Business. While both Microsoft products are part of Office 365 and feature messaging, presence, and voice and video communications, Skype for Business has additional features including PSTN calling and conferencing.

Skype for Business features

Features that are exclusive to Skype for Business Server include Enhanced 911 (E911) and persistent chat, a topic-based discussion session that remains intact after active users leave. As part of the Office 365 Business Essentials and Business Premium plans, Skype for Business Online supports high-definition video and audio conferencing for up to 250 people as well as enterprise-level technical support. Skype for Business is also part of Office 365 Enterprise plans E1, E3, E5 and K1.

Skype for Business Checklist

It offers interoperability with Polycom video conferencing through Polycom RealConnect. The service allows Skype for Business users to conduct sessions with users on Polycom and Cisco video conferencing endpoints. Microsoft has also partnered with video conferencing hardware vendors Logitech and Crestron.

Other features include:

  • Communication control across Windows 8 devices and architectures;
  • File sharing, whiteboarding and screen and app sharing within a communications session;
  • The use of open standards, including the H.264 video codec;
  • Presenter controls optimized for meeting format, audience size and content sources;
  • Custom and automated presence based on Outlook Calendar or Out of Office status;
  • Mobile push notifications, screen reader and external keyboard support;
  • Auto attendant system that answers and routes inbound calls;
  • Call queues that send incoming calls to a customer support agent in the order they are received; and
  • Recording and archiving of meetings, messages, conferencing sessions and sign-in logs;

Add-on licensing options offer other features for additional cost:

  • Dial-in conferencing lets users call into a Skype for Business meeting from a traditional phone.
  • Cloud private branch exchange (PBX) features hosted voice services in Office 365.
  • Public switched telephone network (PSTN) calling telephone service includes calls to non-Skype for Business users.
  • Skype Room Systems v2 brings video, audio and content sharing to conference rooms.

Consumer Skype vs. Skype for Business

Although they share similar names and user interfaces, Skype for Business and its consumer counterpart, Skype, are different products. The latter is free to use, but is limited in functionality and does not offer enterprise support.

Microsoft acquired the consumer version of Skype in 2011 for $8.5 billion. Microsoft Lync was rebranded as Skype for Business in 2015. Changes included a new client interface, a new server release and updates to the UC service in Office 365.

According to Microsoft, the consumer version of Skype is suitable for businesses of up to 20 employees. Consumer Skype is free when both users have installed the application. Communication with non-Skype clients is subject to connection fees that can be paid on a per-call basis or through a monthly subscription.

If a business has more than 20 employees, Microsoft recommends using Skype for Business, which allows connection payments to be managed across the company's network instead of through a series of individually managed accounts. Although consumer Skype and Skype for Business run on different servers, both versions have similar dashboard designs. Skype Connectivity is a feature of the platform that allows users to search for and add Skype users. The two versions of Skype are not federated by default.

Deploying Skype for Business

Skype for Business Server can be deployed on premises or in a hybrid model with cloud connections. The server is available for various deployment sizes, ranging from 4,000 to 100,000 users. In larger deployments, multiple servers are recommended for load balancing and high availability.

At its simplest, deployment requires one Skype for Business Server installed on a Windows 2012 R2 64-bit server to handle user registration, databases, call routing, instant messaging and presence services for internal clients. An edge server is required to support mobile or remote users and help external users download meeting content, update clients and devices, download files from Address Book Server, connect to online meetings using URLs and discover front-end servers offering mobility services.

A component called the Mediation Server translates signals between the internal VoIP infrastructure and PSTN or Session Initiation Protocol (SIP) trunks. The Mediation Server undertakes media transcoding between phone calls, encrypting and decrypting Secure Real-time Transport Protocol 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.

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

This was last updated in July 2017

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