If your company uses Microsoft's Office 365 productivity suite and the service is running at a glacial pace, chances are something has gone wrong. But how do you diagnose the problem and how do you fix it? Microsoft has provided some pointers on how to troubleshoot this issue.
Office 365 sluggishness is often associated with high latency between the client company and the destination of the traffic. This is not problem specific to the productivity suite. Basically any traffic that is encrypted using SSL could experience high latency. This is caused by proxy servers or intermediary devices running SSL inspections and decryption and re-encryption before handing the packets in a flow of traffic to their destinations.
Here's what Microsoft premier field engineer, Lakshman Hariharan, recommends if you want to find out what is causing the Office 365 slowness in your organisation:
"A good way to measure latency to an endpoint from a client is to capture a network trace while accessing the endpoint from an application that uses TCP. If we capture a network trace during the three way handshake, the time delta between the Syn and Syn-Ack packets of the handshake gives you the round trip time."
If the traffic is routed through proxy servers, it will either go straight through and the packets aren't modified at all or it will terminate and recreate all the TCP connections that are being proxied. The latter may be the reason why your Office 365 service is so slow.
Hariharan goes through several common scenarios on his TechNet blog post but overall, he advises:
"In summary, this is in essence how we can establish - via client side-only network traces - whether the traffic you are sending via SSL to a destination is being inspected by an intermediary device.
If you are seeing sluggish performance to SSL sites and/or Office 365 and are seeing similar symptoms on a client side trace, work with your network team to further investigate and hopefully, resolve the issue."
[Via Microsoft TechNet Blogs]