Telex IP-223 - Manual (Page 22)

Communications System Design
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NOTE: When using Cisco technology, IP PIM dense mode is generally recommended. Generally speaking, sparse-
dense-mode can also be implemented effectively. We recommend explicitly joining the multicast group with an
IP IGMP static-join X.X.X.X command. For more information on Cisco and IGMP, visit www.cisco.com
Internet Group Management Protocol (IGMP)
IGMP can be used to control where multicast is allowed to propagate. When a console on the subnet is expected to be
continually operational, multicast must be active for that subnet at all times.
Network Performance
Networks should perform well under any loading conditions. The default audio delay is 120ms, plus any delay added by the
network. While delay alone does not cause issues, variable delay (jitter) does. Jitter in a network cannot exceed the
maximum packet buffer of any individual product buffer. Refer to the individual product manuals for these specifications. For
example, the IP-223 can handle approximately 600ms of network jitter.
NOTE: Losing more than 5% of the total packets transmitted compromises audio quality and system performance.
Optimally, packet loss should be less than 1%.