News

Microsoft Releases Beta of Exchange Bandwidth Calculator

• By Kurt Mackie
• 02/13/2012

Microsoft last week issued a beta of a new Exchange Client Network Bandwidth Calculator.

The beta, which is designed to help those involved in the design phases of Exchange projects, can be downloaded here. Microsoft also provides a guide for using the calculator at this page.

The new tool has been under development at Microsoft for about a year, according to a Microsoft blog post. The company is seeking to improve it with more real-world data before moving off the beta, with a target date to do that by mid-2012. The calculator is designed to work with Exchange deployed on premises, as well with hosted Exchange offered through Microsoft's Office 365 services.

The calculator is based on the use of Microsoft's e-mail clients, such as Outlook 2010, Outlook 2007 and Outlook 2003. Microsoft's Web-based e-mail clients also are supported, including Outlook Web App 2007 and Outlook Web App 2010. It also derives estimates based on Windows Mobile and Windows Phone mobile device e-mail clients.

Currently, the calculator will not create an estimate from BlackBerry e-mail client use or from other non-Microsoft e-mail client use. Microsoft suggests getting the specific bandwidth-use information from those vendors. Also not supported is Outlook 2000 and older versions. Microsoft plans look into adding support for Outlook 2011 and Entourage (the Mac e-mail client) in a future release.

The calculator is an Excel worksheet-based tool that estimates how much bandwidth will be required to optimally support an organization's e-mail traffic, based on the data provided by the user. To use the tool, an IT worker needs to know how many e-mails are received or sent by each individual mailbox, plus the average message size.

Based on those numbers (and a few more), mailboxes will get classified as light, medium or heavy users, with sizes estimated in gigabytes. Microsoft's documentation for the calculator recommends using PowerShell to get the data from Exchange 2007 or Exchange 2010; otherwise, the user will need a reporting tool to get that information.

At the end of the input process, the calculator will arrive at an estimate of the total steady-state bandwidth that will be required for a mailbox migration. Microsoft's documentation recommends that users of the calculator leave some space for bandwidth headroom. For instance, it's a best practice to double the predicted steady state to allow for network usage spikes.

Calculator users can use a Microsoft white paper on Outlook Anywhere to help estimate bandwidth requirements. The white paper has tables on client network traffic that can be used as general guidelines for profiling light, medium and heavy e-mail users. However, Microsoft's blog says that the profiles embedded in the new calculator are more precise than those listed in the white paper.