Zscaler’s goal is to ensure that all end users, regardless of their location, can obtain the first-class user experience that they are after. This effectively means delivering access to Office 365 with < 100ms of true end-to-end latency (wired broadband).
Obviously, it is true that there are multiple elements and data path owners along the way, which is why it is critical to choose each option wisely and why Zscaler’s data centers are increasingly peered with the Microsoft cloud.
Thanks to this peering, proximity, and full-scale cloud performance, there’s simply less complexity/troubleshooting, as well as SLAs that can’t be readily achieved with legacy architectures. Even DNS is optimized by Zscaler, as local DNS resolution takes place at each data center, with query times of <1ms.