If we've stepped through all the network level checks and all looks good from that perspective, then we need to move up the stack to the application itself and see if something above the network is causing performance issues. This can prove tricky...

One of the main things we need to get right to ensure the most efficient and speedy connectivity to O365 is where in the world your DNS call is being completed. You'd think this wouldn't matter, you do a DNS lookup for your O365 tenant, get the...

This is a quick one to check to ensure your TCP packets are able to contain the maximum amount of data possible, low values in this area will severely affect network performance. Maximum Segment size or MSS is a TCP level value which is the largest...

Fw In my previous blog post , I discussed checking the MSS to ensure full sized packets are used. Well, whilst you're digging around in the TCP Options of the SYN-SYN/ACK packets, it's worth checking another option SACK or Selective Acknowledgement...

Proxy servers are often in place at customer sites, happily ticking away handling Internet traffic for years before Office 365 came along. As Office 365 generally travels over port 443 (for Outlook and SharePoint at least) then what's to think about...