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Your Network is the Key to Office 365

Love or hate it, Office 365 is here to stay. For most companies that have not made the transition to the Office 365 yet, I say yet because it is a matter of time before the majority of business are running email in the cloud. When you are planning to move email to the cloud there are many considerations to make and one of them is your network.

Your network is key when you want to live in the cloud. One of the first things you should do after you’ve made decision to go to the cloud is review your network and estimate how much bandwidth you will use. Office 365 adds increased usage because of the synchronization outlook and downloading of templates. The amount of users connecting to the cloud and type of tasks they do will impact your bandwidth. Network performance is impacted by what the users are doing, for instance if everyone is streaming video or having multiple video conference calls on your network that will certainly cause high bandwidth which can impact your connectivity to cloud services.

Migrating to Office is not an overnight task as some may think. It can take week to months to be completely migrated to the cloud and a lot of this depends on your network. It is highly recommended to test and validate your internet bandwidth as this will impact your migration. Mailbox sizes will impact how fast or slow the migration to the cloud will be. Let’s say your organization has about 100TB emails in your on-premise environment and you want to migrate all that to the cloud. I will tell you it will not help happen in days it will be more like months. Keep in mind Microsoft does throttle how much date you pump into their network each night. Let’s just say you are using an internet connection of 100Mbit/s and you are at 100% speed you are looking at least 8-9 months but given that there is throttling involved and possibly other outside factors that would also effect the speed and bandwidth your real estimate would likely be closer to 10-12 months.

Slow internet means slow migration and possible failures along the way.  If your still have slow MPLS sites these are not ideal for Office 365, however Microsoft has partner with a select few providers to use the ExpressRoute. ExpressRoute is a private connectivity to Microsoft Office 365.  Microsoft has some tools that you can use to help estimate your network requirements. One of the important ones to look at is the Exchange Client Network Bandwidth Calculator which estimates the bandwidth required for Outlook, Outlook Web App, and mobile devices.

Once you have made it to the cloud it does not stop there. Ongoing performance tuning maybe needed to ensure that your users are happy and do not experience email “slowness”.  Given that Microsoft has published best practices articles on slow networks for Office 365 I am pretty sure your network guys will be called a lot to check network performance. They do give some recommendations such as:

  • Upgrade to Outlook 2013 SP1 or later for substantial performance improvements over previous versions.
  • Outlook Web App lets you create offline messages, contacts, and calendar events that are uploaded when OWA is next able to connect to Office 365.
  • Outlook also offers an offline mode. To use this, you must first set up cached mode so that information from your account is copied down to your computer. In offline mode, Outlook will try to connect using the send and receive settings, or when you manually set it to work online.
  • If you have a smart phone, you can use it to triage your email and calendar over your phone carrier's network. ( yes this as a real alternative…)

At the end of the day it comes to making sure your network is up to snuff when you are making your way to the cloud or you may have some headaches. Good Luck


Not everything MS does or offers is necessarily a great idea, even when other giants jump on that bandwagon.

Before joining that group of people, verify the cloud's security, and that it provides Six-9's availability / performance / accessibility, and get signed SLA's with the cloud providers--these SLA's must have some real teeth and significant performance/access/security/availability penalties.   Then get the Cloud provider to allow monitoring of cloud resources and security by your own company (or by trusted third parties), etc.

It would be foolish to assume others can provide the same security and access and response times that you can do internally if you have your own data center resources.

My company can save significant amounts of license fees by going to O365.  What will the cost be if O365 becomes unavailable or compromised?  The "saved dollars" figure is something nebulous for now, but it will become definable after an actual extended outage or security event.

If a Wiki-leaks event occurs and it affects your data, what will be the cost to you, your career, your company, and your customers?   Will it be less than the amount of license fees you're saving?

having been on office 365 for almost 3 years E1 level, I can say as a smaller IT shop its been wonderful.   I agree with rschroeder​, however it was the gamble we took as a company at a leadership level.  It'll cost more than my job.   Our parent company of nearly 40K employees also made the jump and it has worked out just as well for them.  

A key for us was to ensure we had AD integration.  We do not have a exchange server in house we are totally cloud.  Utilizing the Synchronization service manager that is free you get all then benefits of SSO with none of the headache.   We have adopted OKTA to assist with other SSO activity, but really the Office 365 migration was a great decision.   We of course got our parent companies buying power so we got a ridiculous discount but still with out it, we would have migrated, but i would have pushed E3 for the office install.  Currently we have to purchase volume licensing for office and in combination it might have been better to go E3 for the user base vs our adoption methods.

For small and medium business I try to push it to my peers, selling the OpEx over CapEx model of business.  Be sure to get the legal hold feature so you have searchable archival for all email.

Level 14

Talk about timing... This thread came along as I am struggling with O365 decision.

I am doing the analysis of O365 right now. I need to replace my mail system (non-exchange)... Security is of prime importance. jeremymayfield​ thank you for your insights, particularly the comments on OPEx and CapEx models... (I am at that point now... and I am using that to make my decision.)

It is risky.... as I said in another post "not all clouds are puffy and white.  "  Film at 11.

I'm impressed!

We moved from a Non-exchange hosted email, which was terrible, to O365.  Support is really good, I usually have a phone call in a matter of an hour or two and might i add from Microsoft its a FREE tech support call.  I have not had a email outage in 3 years (knocking wood) aside from our local internet fiber cut (company self inflicted).

Now there is always that point where you say a cloud solution costs you more at X point in time that a hosted solution, comparing licensing and hardware one time purchases.  However, support, admin requirements, and other savings really keep the costs well below any capital investment.   Also you are always on the latest supported versions, no patching requirements no server reboots, endless groups just like a local exchange server.  With our E1 we also have SharePoint in the cloud, and so many other apps.  Some apps are useful, some not.  Not a big fan of sway, but just because i don't have an immediate need doesn't mean others will not.   It all depends on your industry. 

Having managed Exchange in 3 different companies, over the course of the last 20 years, this O365 email, is the best system i have used.  The admin time saved alone made it worth it for us.

Thanks, my writing is no where as clean as yours but I hope I get my points across.

Level 14

jeremymayfield​ thanks for the info.... Basically same situation here..... Free support is huge...

Support and upgrades are key in my analysis.... I am in the process of evaluation other "important business functions" for potential outsourcing or non-hosted solutions.

btw... hate those self inflicted wounds.... no amount of adult beverages ever take the sting away with those.

Microsoft might be on to something here--free technical support for a new environment they're offering may make a world of difference towards getting that new environment adopted quickly across a wide range of customers.

Level 13

The cloud is going to cause rain and storm clouds.....  Ugg....

Level 20

I've always tried to stay away from email as part of my job... now because of the type of work I do I don't have any choice.  We have to run everything in our environment.  Backups is another area I always tried to stay away from... and once again been dragged into.  It is fun to learn about all the different technologies... some definitely more interesting than others.

I recently ran into a surprise where a VIP declared corporate access to e-mail is not mission critical, while Guest Wireless Internet access IS.

Level 14

Once again, not something the DoD will ever put on a classified network.

Level 13

it's funny - there's always pros and cons to everything and every decision in life, but now, when you talk about IT items its boiled down to Security and Privacy...

Level 14

Oh really now?  (Said in my granddaughter's voice)

Level 10

let me guess, VIP personal ipad not connecting to guest wireless and they can't sync there corporate email account ? at lest they can foward there work emails to there gmail account!!


I assume you can access everything the same way while out on the long as you have internet connectability ?

If so, hopefully it is all via https so it is fairly secure.

Level 21

We are a Microsoft Partner to resell 0365 and we have helped clients make the migration and I would completely agree with everything pointed out here.  If you are considering making the move it's definitely worth your time and money to partner with somebody that has experience and can help you through the process.  We have worked with several companies that have attempted this on their own only to realize they were quickly in over their head.