Skype for Business Server


Skype for Business Server is real-time communications server software that provides the infrastructure for enterprise instant messaging, presence, VoIP, ad hoc and structured conferences and PSTN connectivity through a third-party gateway or SIP trunk. These features are available within an organization, between organizations and with external users on the public internet or standard phones.

Features

One basic use of Lync Server is instant messaging and presence within a single organization. This includes support for rich presence information, file transfer and voice and video communication. Lync uses Interactive Connectivity Establishment for NAT traversal and TLS encryption to enable secure voice and video both inside and outside the corporate network.
Lync Server also supports remote users, both corporate users on the Internet as well as users in partner companies. Lync supports identity federation, enabling interoperability with other corporate IM networks. Federation can be configured either manually or automatically.
Microsoft Lync Server uses Session Initiation Protocol for signaling along with the SIMPLE extensions to SIP for IM and presence. Media is transferred using RTP and SRTP. The live meeting client uses Persistent Shared Object Model to download meeting content. The communicator client also uses HTTPS to connect with the web components server to download address books and expand distribution lists. By default, supported combinations include encrypted communications using SIP over TLS and SRTP as well as unencrypted SIP over TCP and RTP. Microsoft has published details of supported configuration for qualified vendors through Unified Communications Open Interoperability Program.
IM is only one portion of the Lync suite. The other major components are VoIP telephony and video conferencing through the desktop communicator client. Remote access is possible using the desktop, mobile and web clients.
Several third parties have incorporated Lync functionality on existing platforms. HP has implemented OCS on its Halo video conferencing platform.

History

When Microsoft Office Live Communications Server was originally launched on 29 December 2003, it replaced the Exchange Instant Messenger Service that had been included in Exchange 2000, but which was removed from the Exchange 2003 feature set. Holders of Exchange 2000 licenses which included Software Assurance were entitled to receive Live Communications Server as an upgrade, along with Exchange 2003; however, Live Communications Server Client Access Licenses were purchased as normal for new users.
OCS R2 was announced at VoiceCon in Amsterdam in October 2008, a year after releasing Office Communications Server 2007.
Microsoft released Microsoft Office Communications Server 2007 R2 in February 2009. The R2 release added the following features:
Microsoft Lync Server 2010 reached general availability in November 2010. Microsoft Lync 2013 was released to manufacturing in October 2012 with SP1 being released in March 2014.
In 2015, the new version of Lync become Skype for Business with a new client experience, new server release and updates to the service in Office 365. Microsoft has stated that general availability for Skype for Business Server 2019 is targeted for the end of 2018.

Versions

is the primary client application released with Lync Server. This client is used for IM, presence, voice and video calls, desktop sharing, file transfer and ad hoc conferences. With Lync 2013 there will be a release of Lync Light Client with fewer features.
Microsoft also ships the Microsoft Attendant Console. This is a version of the Lync more oriented towards receptionists or delegates / secretaries or others who get a large volume of inbound calls.
Persistent Group Chat functionality is only supported on the Windows OS client at this time. This requires an additional server or multiple servers for processing group chat transactions.
Other client software and devices include:
The documentation of Lync 2013 contains references to Lync Room Edition Devices - these are anticipated to provide close to immersive experience.
Linux support:
Fisil makes the only available supported Linux client for Lync. The unifiedme.co.uk reference lists a Pidgin-based workaround, but according to the information at CERN, it has important limitations. The Damaka reference leads to the Google+ main page and has no information on a Linux client that I could find. The Fisil reference goes to a project management company that can write custom software.

Compliance

Lync Server also has the capability to log and archive all instant message traffic passing through the server and to create Call Detail Records for conferences and voice. These features can help provide compliance with legal requirements for many organizations. The Archiving server is not an overall end-to-end compliance solution, as archiving requires you to install the Archiving Server and to configure front end servers accordingly.

Public IM Connectivity (PIC)

Lync Server also enables organizations to interoperate with four external IM services: AOL Instant Messenger, Microsoft Messenger service, Yahoo! Messenger, and Google Talk. PIC was first introduced with Service Pack 1 for Live Communications Server 2005, PIC is licensed separately for Yahoo, but is free for AOL and Messenger service for customers with Software Assurance. Microsoft announced that effective 30 June 2014, they will no longer support PIC connectivity to AOL/AIM

Third-party software support

SIPE plugin

The third-party enables third-party clients such as Pidgin, Adium and Miranda IM as well as clients using the Telepathy framework to support MS Lync Servers with some limitation via the extended version of SIP/SIMPLE.

XMPP

Lync Server has an XMPP gateway server to federate with external XMPP servers. With Lync Server 2013, XMPP is natively part of the product.
The ejabberd XMPP server has a bridge that enables federation with OCS servers, without gateways.

Competition

Competitors to Lync Server include:
In instant messaging, the free public instant messaging networks are widely used and represent a degree of competition. There have been attempts by other vendors at providing solutions such as Yahoo!'s Enterprise Instant Messenger; however these attempts have been largely unsuccessful. An ICQ corporate client and server option once existed, but it is no longer supported or developed.
Products such as Cisco Unified Presence Server support federation with Microsoft Office Communication Server 2007 to provide presence of Cisco IP phones and remote call control of the IP phone from the Microsoft Office Communicator client.
The Siemens OpenScape solution offers a federation with the Office communicator, and also an integration into the office communicator, allowing to use the standard functionalities of the office communication suite together with the SIP based voice functionalities of the Siemens platform.
The Asterisk telephone platform supports SIP, IAX, and ISDN connections. Most telephones that support these protocols may be used with Asterisk, including software phone clients.