Testing Office 365 Connectivity

Recently had a customer with an issue with accessing Office 365\SharePoint site.  They were complaining that the performance was not great.  So I needed to see what issues they might be having with their network.  Results were really interesting, they were being routed (via ATT) from SJC to CHI to NYC to DUB then back to LAX and finally to the US West data center in SJC.  Woah…that’s definitely not good!

Decided to write down all the tools I use and the script commands I execute to test a sites connectivity to Office 365.

  1. Fiddler
    1. Open a site collection, sort the HTTP requests by latency\execution time
  2. MeasurementLab tools
  3. Ping – Network level
  4. Tracert – Transport level
  5. WireShark – For really tough, weird things that don’t show up in regular network tools (Session, Transport issuse)

Services to ping:

  • Exchange
    • ping outlook.office365.com
      • Ensure you are getting the closest data center:
        • outlook-namcentral3.office365.com –
        • outlook-namnorthwest.office365.com –
        • outlook-apacsouth.office365.com –
        • outlook-emeawest.office365.com –
        • etc…
    •  SharePoint
      • Resolve-DnsName tenant.sharepoint.com
        • Determine DNS servers serving your requests
      • ping tenant.sharepoint.com -t
      • ping (tenant.sharepoint.com)
        • Target latency = <100ms
      • ping (outlook.office365.com)
        • Target latency = <50ms
  •  Skype
    • ping global.tr.skype.com
    • ping -t
      • Target latency = <20ms
  • Azure
  • Other IPs

Services to tracert (use the db-ip.com service to find their locations):

  • tracert
  • tracert

Look up each ip along the way…to see if unnecessary routing is occurring.  If it is, then ISP needs to configure route to data center or customer needs to setup ExpressRoute.


Painful Example:

  • – local router (San Jose)
  • – Chicago (ATT)
  • – New York (ATT)
  • – New York (ATT)
  • – New York (ATT)
  • – Dublin (Microsoft)
  • – Los Angeles (Microsoft)
  • – Los Angeles (Microsoft)
  • – Los Angeles (Microsoft)
  • – San Jose (Microsoft)

Helpful references:

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