4200 User Manual Edgewater Networks, Inc.
Version 3.0 83
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 4200:
Automatically
prioritizes voice
traffic over data
traffic to ensure toll
quality voice calls.
Manages bandwidth
using different
upstream and
downstream link
speeds (e.g. ADSL).
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
upstream TCP
devices to limit WAN link congestion.
Optimizes throughput for low-bandwidth WAN links (eg. ADSL) by
automatically adjusting the Maximum Transmission Unit (MTU) and Maximum
Segment Size of IP datagrams during periods of WAN 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 4200 is to “minimize delay and maximize throughput” or 8p
hexadecimal. This value is set for all VoIP packets processed by the 4200 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 4200 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.
To Next Page
Loading...
