• 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.)

• 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.

Note:
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.