Oracle Primavera Gateway is a web-based application where users request to run synchronization using various browsers, ideally within the same LAN / WAN.
In a typical implementation, you will deploy the Primavera Gateway and P6 Web Services on separate physical servers. So, you must maximize the bandwidth and minimize latency between servers. Ideally, the servers reside in the same data center with gigabit or more Ethernet connection between the servers. (Oracle Primavera performance tests are performed with servers in a central data center with gigabit connections.)