UPDATE DEC-16: The language on the support page linked in this blog has been changed so it no longer appears that it is “not recommended” and more so that customers need to learn, understand and design suitable network scenarios (which is ideal anyway) with ExpressRoute.
Increasingly a number of customers I speak to tell me they are planning to put in ExpressRoute as part of their Office 365 project.
What I have seen change over the past year is the attitude of “tell me about ExpressRoute” to being “oh yes, we’re getting ExpressRoute”.
Well this change to the Microsoft guidance might put the brakes on a lot of those deployments. If you look at the Azure ExpressRoute for Office 365 support page, you’ll see this key line buried in the first paragraph: “Azure ExpressRoute is not required or recommended for Office 365 except where mandated to use direct networking for regulatory purposes or where a network assessment for Skype for Business connectivity requires it”.
Note the key words in there are “not required or recommended” unless it is mandated or Skype needs it for quality purposes.
This does beg the question: why would you use ExpressRoute for Office 365 outside of it being mandated or needed for Cloud PBX? With Azure this makes common sense as you want it to be a logical extension of your network so that applications and virtual machines can easily see each other, and all traffic is “off net” (ie. unmetered). However, with Office 365 the desire is to have users working from wherever they are and not necessarily tied to the corporate network in order to access their services. Certainly having the best of both worlds is optimal – if you’re on the corporate network all traffic is off net and ideally faster, and when outside of the corporate network users access the service via the Internet.
So this change to guidance is something important that organisations need to take heed of as it’s no longer assumed you can simply get an ExpressRoute service to Office 365 just because you want it – you need to have a very good reason that can’t be debated.