Office 365 and VPN
One of the main advantages of using Office 365 lies in the possibility to access to the Office applications, (Outlook, OneDrive, Skype for Business and SharePoint) regardless of whether we are directly connected to our corporate network or not.
Office 365 in fact, is a SaaS software’s (Software as a service) which means that the service is centrally hosted on the cloud (by Microsoft in this case) therefore any organization wont need to keep any server running Exchange/Office365 locally within its on-premises infrastructure.
In other terms, anyone accessing to Office365 will actually be accessing to an environment that is centrally hosted remotely, on a Microsoft server on the cloud.
However in many cases users working from remote sites (located across the network organizational boundaries) might need to use O365 applications while their computers are connected to the net via a VPN software.
Office 365 behaviour will not change simply because a VPN Software is used, but the network traffic will be forwarded to the VPN adapter, so Office 365 might show degradation connectivity problems or connectivity loss, just to mention a few.
What does VPN do?
VPN stands for “Virtual Private Network”.
It can be thought of as a safe tunnel (The connection is encrypted), between your computer and the outside world (The internet, or a remote service you need to connect to)
VPN is often used when the employee is working from a remote location (as before said located across the network organizational boundaries) and needs to reach different organizational resources located instead on-premises ( locally hosted by the Company and requiring a ciphered, secure connection) such as Network Drives, Customer Database Management software, other locally hosted resources.
In this context, its easily understandable why VPN software’s are often used by so-called “External Users” (External consultants from a stakeholder company) working on O365 applications configured with more than one company profile.
For instance, I might be working for Company N1, but I would be cooperating also with a stakeholder Company N2.
In this scenario, I would use two mailboxes configured on my Outlook 2013:
The Mailbox using the email address for the organization I currently work for, (Marco.email@example.com) and the Mailbox using my stakeholder’s company email address (Marco.firstname.lastname@example.org)
As external consultant, I would very likely work on VPN in order access to different companies’ on-premises resources.
For all the above reasons, the standard set up today’s organizations relay on, would include the usage of a Software’s capable of providing and handling VPN connectivity, like Cisco AnyConnect Secure Mobility Client.