This article originally appeared in the April 2012 issue of INTERNET TELEPHONY magazine.

Cloud services can streamline installation and reduce operational costs for enterprise telephony services. They can also increase efficiencies with network consolidation, simplifying IT administration. Microsoft (News - Alert) Office 365, the hosted platform for the Microsoft Office suite of applications, is being widely adopted by the industry for just these reasons. 

In many cases Office 365 is being used with an IP PBX (News - Alert) that is located on the customer premises. An enterprise session border controller plays a critical role in these deployments. By solving network address translation traversal, an E-SBC makes it possible for IP PBXs to connect successfully with Exchange Online UM from behind the enterprise firewall, enabling the use of the Microsoft Office suite of applications hosted on Microsoft Office 365.  

Microsoft Office 365 has specific connection requirements that can be easily addressed by an E-SBC. For instance, Office 365 requires support for secure real-time transfer protocol and transport layer security. SRTP provides one of the most secure environments for VoIP applications available with advanced encryption, confidentiality, message authentication and replay protection. TLS authenticates voice traffic as well encrypting the signaling. Together, this powerful SRTP-TLS combination effectively stops eavesdroppers, hackers and spoofers. 

The E-SBC also provides critical TCP/IP-to-UDP (News - Alert) conversion. Microsoft Office 365 connects using TCP/IP while most IP PBXs support only UDP connections. The E-SBC makes this conversion enabling Office 365 to be used with any IP PBX that is installed at the customer site.

E-SBCs play an important role in enabling the use of Microsoft Office 365.