User's Manual

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 H.323
IP 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
(see
Voice compression channels on page 38). 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.
• The assessment should leave you confident that the implemented network will have the
capacity for the foreseen data and voice traffic, and can support H.323, DHCP, TFTP and
jitter buffers in H.323 applications.
• An outline of the expected network assessment targets is:
Test Minimum Assessment Target
Latency Less than 150ms
Packet Loss Less than 3%
Duration Monitor statistics once every minute for a full
week
Planning
34 Implementing the Avaya B5800 Branch Gateway November 2011
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