
SBC 5100 Configuration Guide 4
© 2012 Sonus Inc. Confidential and Proprietary. All Rights Reserved. Do not distribute without permission.
1 Introduction
This document provides a configuration guide for Sonus SBC 5100 (Session Border
Controller) when connecting to AT&T IP Toll Free service using AVPN or MIS/PNT
transport.
The Sonus SBC 5100 is a Session Border Controller that connects disparate SIP trunks, SIP
PBXs, and communication applications within an enterprise. It can also be used as a SIP
routing and integration engine. The Sonus SBC is the point of connection between the MS
Lync and AT&T IP Toll Free service and is used not only to secure the SIP trunk, but also to
make adjustments to carrier and enterprise signaling for interoperability.
1.1 Special Notes
1.1.1 Mid-call Re-INVITEs
The Sonus SBC 5100 does not send out the shuffling Re-INVITES and Hold-Resume Re-
INVITES from the MS Lync to the Network unless there are changes in the media
information.
The Re-INVITES received from the MS Lync with changes only in the media source
information will not be relayed to the Network. However, changes in the media codecs, p-
time or media attributes will be relayed to the Network.
1.1.2 Emergency 911/E911 Services Limitations and Restrictions
AT&T provides 911/E911 calling capabilities but does not warrant that the equipment and
software (example, IP PBX) reviewed in the customer configuration guide will properly
operate with AT&T IP Toll Free to complete 911/E911 calls. Therefore, it is the Customer's
responsibility to ensure proper operation with its equipment/software vendor.
AT&T IP Toll Free services support E911/911 calling capabilities under certain Calling Plans.
But, there are circumstances when that E911/911 service may not be available, as stated in
the Service Guide for AT&T IP Toll Free found at http://new.serviceguide.att.com/. Such
circumstances include (but are not limited to):
Relocation of the end user's CPE
Use of a non-native or virtual telephone number
Failure in the broadband connection
Loss of electrical power