[ro_dreaming]

The company I work for is splitting into two companies. We use O365 (as so many do). But, we have sites all over the US (and the world, really), which use either MPLS circuits or IPSEC VPN tunnels back to HQ or one of the data centers, then goes out the internet. Guest traffic at the remote sites usually goes straight out with a limited set of abilities (80/443 usually), after going through our cloud proxy service.

We pushed 93000 users from one org to another org over the weekend.

Our HQ/DC ISP pipes have been at 80% or more (98% was the highest sustained) since as people TRY to do normal work while also downloading 5+ Gb Outlook PST files.

Ugh.

/someone should have done a phased rollout - week 1 A-E, week 2 F-M, week 3 N-R, week 4 S-Z, something other than bull rush.

Desktop in the cloud would have been an even WORSE nightmare.

[StAnDeliver]

"Our HQ/DC ISP pipes have been at 80% or more (98% was the highest sustained) since as people TRY to do normal work while also downloading 5+ Gb Outlook PST files."

Why on earth is it necessary to physically exchange tomes when that is not only the raison d'etre of Microsoft Exchange but remarkably the sub rosa of the actual article up top.

You don't have to answer, of course, respect the security, but genuinely puzzled.

[usconservative]

If you're using O365 why are you backhauling all that traffic across your corporate network to the end user?

Split-tunneling is your friend with O365. Let that traffic go out their local internet connection and stop backhauling it across the corporate network.

That's what we do. Works great and your end users will thank you.