Reference13r1:Concept Update Server
Use of the Update Server in v13r1 and v13r2
From version 13r1 the update server is deprecated and the Devices App is used instead. Parallel usage of both the update server and Devices is not recommended as the old update server would interfere with Devices' provisioning mechanism.
Of course, you could run the update server alone without using Devices at all. However, this is not recommended.