Understanding the SBA and the ASM

Does not apply to SBC SWe Lite.

A Survivable Branch Appliance (SBA) is a device that increases the resiliency of branch office communications during network failures because it is able to switch Lync VoIP calls from the network over to the PSTN. Sonus offers this functionality for Lync and Skype for Business within the SBC Edge using an Application Solution Module (ASM) that hosts the Microsoft SBA component.


Microsoft proscribed the functionality and security model for the SBA. Sonus is responsible for the method used to reach the Microsoft recommendation.


The Sonus ASM operates in either of two modes:

  • In Appliance mode, the SBA utilizes Sonus' solution to guarantee security and reliability. Sonus fully support the ASM (Hardware and Software)
  • In Server mode, the SBA is customized by the customer with a solution not tested or approved by Sonus. Customization can be for functionality or security purposes. Sonus doesn’t know the impact of this customization, therefore can only support the Hardware components.

By default, all ASMs are shipped in Appliance mode. Any customization you undertake will turn the ASM into Server mode. The only way to return to Appliance mode is to re-initialize the ASM using the on-board capability via the WebUI.

Managing the ASM
Managing the Skype Lync SBA
Managing the CCE