Microsoft ExpressRoute is not always the best and fastest route
Over the weekend Microsoft's Senior Program Manager -CXP, Paul Collinge, posted a great powerpoint presentation on "Overcoming Network Performance Blockers for Office 365 Deployments".
What was particularly interesting were some of his insights and comments regarding ExpressRoute via Internet Route to Microsoft's extensive worldwide cloud network.
"A good internet connection may give similar or better performance [than ExpressRoute]", Paul Collinge, Microsoft.
Microsoft has built an extensive, reliable and very fast global network which includes their cloud infrastructure as well as big private redundant leased lines between their data centres, Microsoft partners and peers to providers all around the world.
However, is Microsoft ExpressRoute the best option? In short, the answer is "sometimes". Sometimes ExpressRoute is the best option and other times it is not.
ExpressRoute often encourages a hub and spoke network model which may actually increase latency when compared to direct connection. Many people think of ExpressRoute as the best way to get to Microsoft cloud, however caution has to be taken with such a simplistic view.
This is one way to think about the connection into Microsoft's network.
This is yet another, and also correct, view of the same situation. Especially so for larger global network deployments.
If you think of latency as the length of each line (ExpressRoute and Internet Route), then you can see in diagram 2 that the latency is better (lower) via the 'Internet Route'.
For those of you who want to understand the importance of network performance to Office 365, we highly recommend reading Paul's presentation here.