Branch-site resiliency features in Lync Server 2013


Topic Last Modified: 2014-02-10

If you provide branch-site resiliency, if a branch site’s WAN connection to a central site fails or if the central site is unreachable, the following voice features should continue to be available:

  • Inbound and outbound public switched telephone network (PSTN) calls

  • Enterprise calls between users at both the same site and between two different sites

  • Basic call handling, including call hold, retrieval, and transfer

  • Two-party instant messaging

  • Call forwarding, simultaneous ringing of endpoints, call delegation, and team call services, but only if the delegator and delegate (for example, a manager and the manager’s administrator), or all team members, are configured at the same site

  • Call detail records (CDRs)

  • PSTN dial-in conferencing with Conferencing Auto-Attendant

  • Voice mail capabilities, if you configure voice mail rerouting settings. (For details, see Branch-site resiliency requirements for Lync Server 2013.)

  • User authentication and authorization

The following features will be available only if your resiliency solution is a full-scale Lync Server deployment at the branch site:

  • IM, web, and A/V conferencing

  • Presence and Do Not Disturb (DND)-based routing (where calls are prevented from ringing on extensions that have DND activated)

  • Updating call forwarding settings

  • Response Group application and Call Park application

  • Provisioning new phones and clients, but only if Active Directory Domain Services is present at the branch site.

  • Enhanced 9-1-1 (E9-1-1)

    If E9-1-1 is deployed, and the SIP trunk at the central site is not available because the WAN link is down, then the Survivable Branch Appliance will route E9-1-1 calls to the local branch gateway. To enable this feature, the branch-site users’ voice policies should route calls to the local gateway in the event of WAN failure.


SBA (survivable branch office) is not supported for XMPP. Users homed in a SBA configurations will not be able to send IMs or see Presence with XMPP contacts.