User manual

4300T User Manual Edgewater Networks, Inc.
Version 1.7 37
Traffic Management Configuration
Traffic management is required to ensure high quality voice calls when both voice
and data traffic share the same WAN link. Voice traffic must be prioritized for
transmission over data traffic to meet the stringent jitter, latency and packet loss
requirements for toll quality voice. The 4300T:
 Automatically prioritizes voice traffic over data traffic to ensure toll quality
voice calls.
 Maximizes WAN link utilization by allowing data traffic to burst up to full line
rate in the absence of voice calls.
 Controls the data transfer rate of far-end WAN TCP devices to limit WAN link
congestion.
 Supports network-based QoS applications by setting the TOS bits for all VoIP
packets sent to the WAN and the LAN. TOS bits are used so that VoIP packets
can be prioritized in the network by DiffServ enabled routers. The TOS bit
value used by the 4300T is to “minimize delay and maximize throughput”, or
0xb8 hexadecimal. This value is set for all VoIP packets processed by the
4300T and overwrites any specific TOS bit configuration set by VoIP
endpoints.
 Ensures that bandwidth allocated to new voice calls does not adversely affect
the quality of existing active calls (Call Admission Control or CAC).
The 4300T combines sophisticated traffic management mechanisms including
classification, prioritization, queuing, rate limiting and CAC to ensure toll quality
voice calls. Fortunately the system manages this complexity for you and configuring
traffic management is very straightforward:
1. Enable traffic shaping.
2. Specify the upstream and downstream bandwidth of your WAN link.
3. Enable CAC.
Please follow the steps below to configure and enable traffic management.