BPOS or Office 365 Bandwidth needs determination: A Refresher

Woody Walton 2010

Woody Walton

Hello and Happy New Year!  You may have seen my post last month on Moving your customers to BPOS or Office 365? Check their BANDWIDTH! The SpeedTest tool is a great start, but you may require some guidance on what is needed from a bandwidth perspective from a normal or heavy user of the Exchange Online component.  Better yet, if your customer’s user base is diverse from a light/heavy Outlook use standpoint, or they OWA extensively, how do you plan?  What about SharePoint, LiveMeeting, Directory Synchronization or Mailbox migration??

We have actually had some great guidance for quite some time.  I actually did a post on this on our retired blog well over a year ago.  As that post is now “gone” I thought would comment on where to look and what to consider.

The Best Point of reference at present to my knowledge is the Online Services Help and How-to article: Company Network Requirements

You can find a wealth of information in various articles on this site.  Click the image below to search the various articles:


Now, back to the Company Network Requirements Article.

The Article is broken down into three main sections, Network Configuration, Bandwidth Considerations, and Migration and Directory Synchronization Tools.

Network Configuration:

This is a small section that relates only the ports needed by Microsoft Online Services.  VERY straight forward.  I have pasted the table below.


Bandwidth Scenarios:

This is the meat and potatoes of the the article.  It is broken down into subsections around each service in the suite.

Exchange Online

SharePoint Online

Office LiveMeeting

These sections provide explicit guidance on what is needed to have a good experience with each of these services and provides example scenarios to illustrate how to do the math.

The values were based on the following assumptions, so you may want ot modify the estimates based on your customer’s type or extent of use:

  • The average message size is 50 kilobytes (KB).
  • Every message delivered is read.
  • Half of all incoming mail is deleted.
  • OWA clients log on and log off two times per day.

Exchange Online

I have pasted the two tables of note that share the archetypical bandwidth consumed by various types of Exchange Online use.  Note the stark difference between Outlook 2007/2010 use versus OWA only!  500% increase in bandwidth consumption in most cases.


I have pasted one example provided below.  Please refer to the article for others.

The example assumes that the users are in the same time zone and that they perform most of their work during the same eight hours of the day.

Example: If your company has 100 heavy Office Outlook 2007 users, here’s how to calculate the average network traffic, measured in bytes per second.
Network bytes/sec = (100 heavy users × (5,200 KB/user ÷ day)) ÷ (8 hr/day × 3600 sec/hr) = 18.5 KB/sec
Assuming a daily peak of twice the average usage, your network connection would need to support approximately 37 KB/sec.


SharePoint Online

I do not want to reproduce the entire contents of the article, but the assumptions for SharePoint online are as follows:


  • An average interaction (page load) transfers approximately 100 KB.
  • A typical user generates about 36 interactions (page loads) per hour.
  • About 10 percent of a company’s users will be active at the same time.

Examples are included that leverage these assumptions to provide some general guidance.

Office LiveMeeting

Requirements for Data transfer, Voice, Video, and Round Table (now the  Polycom CX5000) are all included.  Keep in mind these requirements are cumulative for LiveMeeting.  Data+Voice+Video, etc.

Migration and Directory Synchronization Tools

Some great information on Migration and synchronization is included as well.  You will find summary information on how to best migrate mailboxes (pointers to more detailed info) and synchronization time estimates for initial sync and subsequent syncing for AD.   Below is a screen shot of the sync time table for mail enabled objects, YMMV:


I will leave you to take to a look.   Partners that I speak to are always use this information when sizing bandwidth for BPOS deployments.  There are also some other resources you might want to consider such as:

White Paper- Outlook Anywhere Scalability with Outlook 2007, Outlook 2003, and Exchange 2007

Plan for bandwidth requirements

Microsoft Office Live Meeting (2007 version) system requirements

About E-Mail Migration

About Directory Synchronization





Comments (2)
  1. SD says:

    How do you reach out with the calculation of  1300KB/User/Day & 6190KB/User/day ?

  2. shiva prasad says:

    Need help in calculating the same for 100 users connecting to office 365 as they reach office and all mails starts downloading at a time at morning 9 when office starts mat be each user might have some 10 MB mails to download.

Comments are closed.

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