Jamie Stark wrote on the Lync Team Blog about networking protocols underlying Lync:

Networking is very much in the DNA of Lync, so when the industry started rallying around Software-Defined Networking (SDN), we were excited to participate. SDN has been defined in a bunch of ways and I encourage you to explore the topic, but generally you can think of two things. First, separating the low-level network functions into commodity hardware controlled by a software-based platform. Second, having applications inform the software controller of their requirements of the network. This concept started with cloud-scale data centers and has been moving down-market as enterprise network architects realize the power of this model.

SDN ensures that virtual machines (VMs) can be managed independently of the underlying network fabric. Stark writes that the Lync team also sees a benefit for unified communications. UC network elements such as routers, reverse proxies, intrusion detection systems, application delivery controllers, firewalls, and session border controllers  need to be provisioned and configured correctly for optimal media flow.  SDN’s single policy-based method of operations, in which the application tells the network what needs to happen, support the smooth operation of these elements. 

The blog discusses the Lync SDN API, which provides a REST-ful data stream of information about media flows as they are started. An SDN controller can use this data in three ways:

  • Diagnostics. Network monitoring systems can use the data to correlate between media flows in Lync and network activities that affect quality.
  • Automatically provisioning QoS. An SDN controller can use information about a media flow starting up and can instruct the network to assign real-time, appropriate marking to those packets.
  • Orchestration. Elements in any layer of the network, from Layer 1 to Layer 7, can be operated in harmony.

For more information, read the blog post or visit the Microsoft Software-Defined Networking Solutions page.