There are many variables to consider when estimating network traffic. Some of these variables are:
? The Office 365 service offerings that your company has subscribed to.
? The number of client computers in use at one time.
? The type of task each client computer is performing.
? The performance of your Internet browser software.
? The capacity of the network connections and network segments associated with each client computer.
? Your company‘s network topology and the capacity of the various pieces of network hardware.
For helpful information to estimate the network bandwidth your organization will require when using Exchange Online and SharePoint Online, see the TechNet article Company Network Requirements. For information regarding bandwidth requirements for Lync Server 2010 conferencing, review the TechNet article Defining Your Requirements for Conferencing.
Look for BPOS Bandwidth Calculator