Synthetic transactions are PowerShell cmdlets built into Lync Server that are used to simulate activities performed by servers or users in our Lync deployment. They are a way to test a Lync service in an accurate way. Although it is possible to use synthetic transactions manually, the Lync management pack for SCOM, Microsoft Lync Server 2013 Remote Watcher Management Pack (that we introduced in the previous section), enables the use of synthetic transactions for active and automated monitoring of our Lync infrastructure. The previously mentioned feature requires a server (called watcher node) that will actually periodically run the synthetic transactions. A watcher node is required for every Lync site that we want to monitor with the previously mentioned feature.