Part 1: How Skype® for Business 2015 - SfB - (Lync® 2013) can be deployed


Overview:

This paper provides an overview of the various methods in which Skype® for Business 2015 - SfB - (Lync® 2013) can be deployed and is Part 1 of a series that specifically looks at Microsoft Skype for Business 2015 (Lync 2013) and the challenges and solutions for integrating Skype for Business 2015 with H.323 or SIP standards compliant videoconferencing systems. Hence, it will focus on the communications used in A/V Conferencing and Application Sharing.

We will show the four main methods of deploying Skype for Business 2015; listing their servers and indicating the connections along with the protocols that they use.

As you read through this and the other papers, it should become apparent that Skype for Business 2015 is modular and that there is no one solution that covers everything. If there was, for a vast majority of cases, this would be an inappropriate and expensive solution as it would have to include a lot of redundant functions that were not needed.

Hence, the purpose of these papers are to provide an overview of Skype for Business 2015 so that the reader has an understanding of the servers, their roles and their functions and is therefore in a better position to determine what they actually need for their specific Skype for Business 2015 deployment. Whilst we will specifically look at A/V Conferencing and Application Sharing and how these integrate with H.323 systems, we will also touch on the components and roles required for Instant Messaging (IM) and Enterprise Voice.

Within these papers, the terms Lync, Skype, Skype for Business and SfB, unless stated otherwise, all refer to Skype for Business Server 2015. The paper is specifically based on Skype for Business 2015. Whilst Lync 2013 has now been renamed Skype for Business 2015, it is generally backwards compatible with Lync Server 2013.

It is recommended that you look all the papers listed below for a background into Skype for Business and a detailed explanation about the Codecs, Protocols, Procedures and some of the available solutions.

History:

Microsoft Lync is an evolutionary product for Unified Communications (UC). The initial product; Live Communications Server 2003, was only an Instant Messaging (IM) server. This then evolved through several interactions of Live Communications Server to Office Communications Server and then to Lync Server 2010; when a PBX replacement function was added. It then evolved even further to Lync Server 2013 which added much more including video conferencing, web and audio conferencing, softphone and PBX replacement and/or integration. Now, Microsoft have renamed Lync to Skype for Business.

Overview of how Skype for Business 2015 can be deployed:

Essentially, there are four methods in which companies can deploy SfB 2015. These are:

  • On-Premise where all the SfB Servers are effectively located and managed in-house.
  • Hosted similar to On-Premise but where the SfB Servers are hosted and managed by a third-party service provider.
  • Skype Online or as part of Office 365, where Skype is hosted by and uses Microsoft servers (...onmicrosoft.com).
  • Skype Online/Server Hybrid combines Skype Online (Office 365) with On-Premise deployment of SfB Server 2015.
  • On-Premise deployment:

    SfB can be deployed On-Premise as part of the company’s overall IT infrastructure. The advantage being that everything is located, managed and controlled in-house. This makes it much easier to integrate into the companies IT infrastructure including 'Office' applications, 'Contacts' and Security Policies. But you then have to maintain and support the Lync deployment.  

    The above diagram shows the servers in a typical On-Premise Skype for Business 2015 deployment that supports video conferencing, web and audio conferencing, VIS, instant messaging (IM), application sharing and PBX replacement and/or integration.

    The diagram also provides an indication of the external traffic and protocols through the Edge Pool, Reverse Proxy and ADFS Proxy into the Skype for Business environment. It intentionally does not show the traffic and protocols within the SfB On-Premise environment between the various Servers and their roles. However, we will specifically look at traffic and protocols used in A/V Conferencing and Application Sharing in a separate paper.

    Hosted SfB 2015 deployment:

    Hosted SfB 2015 offers similar functionality to On-Premise deployment; the difference being that the main servers are hosted and managed by a Service Provider. The advantage being that you don't need dedicated support staff to managed, maintain and control the deployment. It can also be integrated into the companies IT infrastructure for access to 'Office' applications, 'Contacts' and Security Policies.

    The above diagram shows the servers in a typical Hosted SfB 2015 deployment that supports video conferencing, web and audio conferencing, IM, application sharing and PBX replacement and/or integration.

    The diagram also provides an indication of the external traffic and protocols through the Edge Pool, Reverse Proxy and ADFS Proxy into the Service Providers Skype for Business environment. It also shows the traffic and protocols between the On-Premise SfB Users and Service Provider. However, it cannot show the traffic and protocols within or between the Service Provider and On-Premise environments as this really depends on exactly what the Service Provider supplies and where each of SfB Servers are located.

    Skype Online or Office 365 deployment:

    Skype Online (or as part of Office 365) is hosted by and uses Microsoft Azure cloud. It is a subscription service that the Skype UC endpoint clients logon too. As such, they need internet access and sufficient bandwidth to ensure that each Skype Online client can perform and meet their expectations.

    The above diagram shows the servers in a typical Skype Online deployment that supports video conferencing, web and audio conferencing, IM and application sharing.

    Skype Online/Server Hybrid deployment:

    Skype Online/Server Hybrid combines the benefits of Skype Online (Office 365) with an On-Premise deployment of Skype. Supported in SfB Server 2015 (and in Lync Server 2013), this is involves an organisation 'Federating' their Skype Online deployment with their SfB On-Premise deployment, thus enabling the same SIP Domain to be applied to both the Online and On-Premise users. Hence, SfB users within the organisation can easily move between using Skype in the cloud or Skype On-Premise. With this hybrid deployment, Skype Online users also have access to, and can use, the available Skype On-Premise infrastructure such PSTN connectivity. 

    The above diagram shows the servers in a typical Skype Online/Server Hybrid deployment that supports video conferencing, web and audio conferencing, IM and application sharing.

    SfB 2015 Servers, Roles and Functions:

    SfB Server 2015 relies on a number of external components in order to function. These consist of various systems such as servers and their operating systems, databases, authentication and authorising systems, networking systems and infrastructure as well as telephone PBX systems.

    Skype for Business Server 2015 is available in two versions, Standard Edition and Enterprise Edition. These two versions allow a variety of deployment options depending on the organisations requirements and budget. Whilst features between the two versions are similar, Enterprise Edition provides options for more scalability along with high-availability and disaster recovery that are not supported in Standard Edition. Hence, Enterprise Edition requires more investment and higher specification components compared to Standard Edition.

    SfB Server 2015 is modular and made-up of several specific roles. Some of these roles can be combined on multiple servers to provide fault tolerance and high-availability. When combined across multiple servers they are called a Pool. For example, a large organisation requiring high-availability might use SfB Server 2015 Enterprise Edition and deploy the Front End role across multiple servers in a Front End Pool along with several mirrored Back End SQL Servers for the database in a Back End SQL Pool. SfB Server 2015 Enterprise Edition requires full SQL on a dedicated Back End SQL Server or Pool.

    Alternatively, SME's who want to introduce unified communications to their organisation might use SfB Server 2015 Standard Edition that can combine several roles onto one server. For example, the Standard Edition automatically installs SQL Server Express with the Front End Server and uses this database to store Skype information.

    SfB Server 2015 Standard Edition offers a relatively low cost entry point based on that all components can be hosted on a single server; with the addition of an Edge Server if external connectivity is required. SfB Server 2015 Standard Edition also supports Front End Pool pairing, which adds some resiliency across multiple servers and sites.

    Hence, an SME could typically deploy SfB Server 2015 Standard Edition on a single server that acts as a Front End Server, with additional collocated roles such as Mediation Server, Persistent Chat Server, Monitoring and Archiving Server. To this they could add an Edge Server for external connectivity and a SIP-PSTN Gateway to enable Enterprise Voice. Together, these would be enough to provide the SME with A/V & Web Conferencing, IM & Presence, Application Sharing and Enterprise Voice. 


    For a complete picture, please take a closer look at all the other papers in this series about Skype for Business 2015. 


    References:
    Technical diagrams for Skype for Business Server 2015 "https://technet.microsoft.com/EN-US/library/dn594589.aspx"
    Microsoft Lync Server 2013 Unleashed. ISBN-13 978-0-672-33615-7