Assessing Office 365 network connectivity

Office 365 is designed to enable customers all over the world to connect to the service using an internet connection. As the service evolves, the security, performance, and reliability of Office 365 are improved based on customers using the internet to establish a connection to the service.

Customers planning to use Office 365 should assess their existing and forecasted internet connectivity needs as a part of the deployment project. For enterprise class deployments reliable and appropriately sized internet connectivity is a critical part of consuming Office 365 features and scenarios.

Network evaluations can be performed by many different people and organizations depending on your size and preferences. The network scope of the assessment can also vary depending on where you're at in your deployment process. To help you get a better understanding of what it takes to perform a network assessment, we've produced a network assessment guide to help you understand the options available to you. This assessment will determine what steps and resources need to be added to the deployment project to enable you to successfully adopt Office 365.

A comprehensive network assessment, like those prescribed in the Skype Operations Framework will provide possible solutions to networking design challenges along with implementation details. Most network assessments will indicate network connectivity to Office 365 can be accommodated with minor configuration or design changes to the existing network and internet egress infrastructure.

Some assessments will indicate network connectivity to Office 365 will require additional investments in networking components. For example, investments in WAN bandwidth or optimized routing infrastructure to support internet connectivity to Office 365. Occasionally an assessment will indicate network connectivity to Office 365 is influenced by regulation or performance requirements for scenarios such as Skype for Business Online media quality. These additional requirements may lead to investments in internet connectivity infrastructure, routing optimization, and specialized direct connectivity.


Microsoft authorization is required to use ExpressRoute for Office 365. Microsoft reviews every customer request and only authorizes ExpressRoute for Office 365 usage when a customer's regulatory requirement mandates direct connectivity. If you have such requirements, please provide the text excerpt and web link to the regulation which you interpret to mean that direct connectivity is required in the ExpressRoute for Office 365 Request Form to begin a Microsoft review. Unauthorized subscriptions trying to create route filters for Office 365 will receive an error message.

Key points to consider when planning your network assessment for Office 365:

  • Office 365 is a secure, reliable, high performance service that runs over the public internet. We continue to invest to enhance these aspects of the service. All Office 365 services are available via internet connectivity.

  • We are continually optimizing core aspects of Office 365 such as availability, global reach, and performance for internet based connectivity. For example, many Office 365 services leverage an expanding set of internet facing edge nodes. This edge network offers the best proximity and performance to connections coming over the internet.

  • When considering using Office 365 for any of the included services such as Skype for Business Online voice, video, or meeting capabilities, customers must complete an end to end network assessment and meet requirements using our Skype Operations Framework. These customers will have several options to meet specific requirements for cloud connectivity, including ExpressRoute.

Have a look at Microsoft's case study Optimizing network performance for Microsoft Office 365. If you're evaluating Office 365 and aren't sure where to begin with your network assessment or have found network design challenges that you need assistance to overcome, please work with your Microsoft account team.

Also, read Office 365 Network Connectivity Principles to understand the connectivity principles for securely managing Office 365 traffic and getting the best possible performance. This article will help you understand the most recent guidance for securely optimizing Office 365 network connectivity.

The Office 365 Network Onboarding tool

You can use the Office 365 Network Onboarding tool, a new proof of concept (POC) tool, to run basic connectivity tests that provide specific guidance about networking connectivity improvements that can be made between a given user location and Office 365.

The Network Onboarding tool does the following:

  • Detects your location, or you can specify a location to test
  • Checks the location of your network egress
  • Tests the network path to the nearest Office 365 service front door

The tool displays the following information:

  • Results and impact tab
    • The location on a map of the in-use service front door
    • The location on a map of other service front doors that would provide optimal connectivity
    • Relative performance compared to other Office 365 customers near you
  • Details and solutions tab
    • User location by city and country
    • Network egress location by city, state and country
    • User to network egress distance
    • Office 365 Exchange Online service front door location
    • Optimal Office 365 Exchange Online service front door(s) for user location
    • Customers in your metro area with better performance

You can read about the Office 365 Network Onboarding tool release and provide feedback at the Office 365 Network Performance tool POC release blog post. Information about future updates to this tool and other Office 365 networking updates will be posted to the Office 365 Networking blog.

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See also

Office 365 Network Connectivity Overview

Office 365 Network Connectivity Principles

Managing Office 365 endpoints

Office 365 URLs and IP address ranges

Office 365 IP Address and URL Web service

Office 365 network and performance tuning