Configuration manual

cases where a specific number should still be routed via the branches own PSTN
trunks.
• PSTN trunk fallback on page 296 — The B5800 Branch Gateway can be configured to
allow some calls that would normally use the Avaya Aura
®
Session Manager line to be
routed via the PSTN when the Avaya Aura
®
Session Manager line is not available.
The various methods used in the these examples can be combined to match the customer's
needs. However the main aim should be as follows:
• To keep the branch configuration as generic as possible, i.e. to use the same PSTN call
control in all branch configurations. This simplifies maintenance of multiple branches.
• To centralize as much of the PSTN call control in the Avaya Aura
®
Session Manager as
possible. Again this simplifies maintenance and control.
Network assessment for VoIP requirements
B5800 Branch Gateway is a converged telephony system, that is, it combines aspects of
traditional PABX telephone systems and IP data and telephony systems. This works at various
levels.
• Individual phone users can control the operation of their phone through applications
running on their PC.
• Data traffic can be routed from the LAN interface to a telephony trunk interface, for
example a dial-up ISP connection.
• Voice traffic can be routed across internal and external data links. This option is referred
to as voice over IP (VoIP).
The VoIP mode of operation can include IP trunks between customer systems and/or SIP
telephones for users. In either case the following factors must be considered:
• The B5800 Branch Gateway control unit must be fitted with voice compression channels.
These channels are used whenever an IP device (trunk or extension) needs to
communicate with a non-IP device (trunk or extension) or a device that uses a different
codec.
• A network assessment is a mandatory requirement for all systems using VoIP. For support
issues with VoIP, Avaya may request access to the network assessment results and may
refuse support if those are not available or satisfactory.
A network assessment includes a determination of the following:
• A network audit to review existing equipment and evaluate its capabilities, including its
ability to meet both current and planned voice and data needs.
• A determination of network objectives, including the dominant traffic type, choice of
technologies, and setting voice quality objectives.
Network assessment for VoIP requirements
Implementing B5800 Branch Gateway for a CS 1000 Configuration October 2012 41