Office 365 is a distributed software to service offering that provides productivity and collaboration tools and applications. 

Office 365 clients like Outlook, Word, and Excel, run on user computers connecting to other Office 365 components that run in Microsoft's data centers. The quality of the Office 365 end user experience is largely determined by the network reliability and latency between Office 365 clients and the Office 365 service in the cloud. Over the next few lectures, you'll learn about Office 365 networking requirements, and why Office 365 networking requires a different approach to network optimization than typical internet traffic. 

Ultimately the goal of Office 365 networking is to optimize the end user experience by enabling least restrictive access between end users and the Office 365 endpoints closest to them. The end user experience is almost always directly related to the performance of whatever application the user is using. A good example of this is Microsoft Teams. Microsoft Teams unsurprisingly, relies on low network latency so that user phone calls, conferences, and shared screen collaborations, work as expected. 

Outlook, which is another good example, requires stable networking connectivity for instant search features that leverage server side indexing. When designing a network for Office 365 connectivity, the goal should be to minimize latency by shortening the round-trip from user machines to the Microsoft Global Network. That being said, optimizing network performance for Office 365 use, doesn't need to be terribly complicated. By following just a few core principles you can attain solid performance. 

Key principles to follow include identifying Office 365 network traffic, allowing local branch egress of Office 365 traffic to the internet from each location instead of funneling all traffic through a central location, and allowing Office 365 traffic to bypass proxies and packet inspection devices. If you follow these three key principles you should greatly improve Office 365 performance for end users. 

Office 365 services are designed for optimal performance through the use of endpoint security and encrypted network connections. What this does is reduce the need for perimeter security enforcement. Because Office 365 data centers are located all over the world, the service is designed to leverage various methods to connect end users to the best available service endpoints. Because user data is essentially distributed across numerous Microsoft data centers, there really is no single network endpoint for end users to connect to. As a matter of fact, data and services in an Office 365 tenant, are dynamically optimized by Microsoft to adapt to whatever geographic locations they're being accessed from. 

Common performance issues that are created when an organization fails to adhere to the three previously mentioned principles include high latency, which can cause terrible audio and video performance, slow data retrieval, slow searches, poor real-time collaboration, inaccurate calendar for your busy information and more. Other performance issues include high round trip times and protocol errors. By shortening the network path from end users to Office 365 entry points via local egress, you can vastly improve connectivity performance and in turn, the end user experience in Office 365. 

The image that you see on our screen shows what a typical egress configuration should look like. By leveraging the local egress architecture, you can ensure optimal Office 365 performance because route lanes to Office 365 are shortened. End user connections are then dynamically routed to the nearest Office 365 entry point by the Microsoft Global Networks Distributed Service Front Door infrastructure. Traffic is then routed internally to data and service endpoints over Microsoft's ultra-low latency high availability dark fiber. A local egress architecture also reduces the load on corporate network infrastructure since branch traffic bypasses corporate proxies and traffic inspection devices. 

Ultimately the ability to optimize Office 365 network performance comes down to removing network connectivity impediments. Treating Office 365 connections as trusted traffic allows you to prevent latency caused by packet inspection and competition for proxy bandwidth. Allowing local connections between end users and Office 365 endpoints, allows the Microsoft Global Network to dynamically route traffic as necessary.