Troubleshooting
N4321D Manual
54
Appendix B: Minimum Network Requirements
The following list specifies the minimum network requirements that must be considered when deploying
your N-Series equipment. These requirements cover the necessary protocols and features needed to
drive N-Series streams.
NOTE:
Specific configuration recommendations are based off the Cisco Catalyst series, however this may vary.
1.
Managed Network Switch
2.
Gigabit Ethernet
3.
Internet Group Management Protocol (IGMP) Version 2
IGMP Snooping
IGMP Snooping Querying
Network must include at least one IGMP Querier to maintain stream connections. It is
recommended to have all capable switches with the querier enabled and allow IGMP
auto-elect to determine the Designated Querier (DQ).
Query Interval – 30 seconds. This is the interval between sending IGMP general queries.
Query Response Interval – 10 seconds. This is the maximum time the system waits for a response
to general queries.
Last Member Query Interval – 100 milliseconds. This is the interval to wait for a response
to a group specific or group- and-source-specific query message.
Immediate Leave (also known as Fast Leave, etc. depending on switch manufacturer).
-
Immediate Leave breaks any daisy chaining of multiple units together with a single home
run, therefore you will not be able to have both Immediate Leave units and daisy
chaining on the same VLAN.
NOTE:
If Immediate Leave is disabled, set IGMP Robustness to Default 2. Robustness can be
adjusted generally from 2-10. The higher the value, the more leave latency is added.
Warnings/Notices
There is a known behavior within IGMP that Encoder streams, whether requested
across an uplink or not, will be requested by the DQ and will be present on all
uplinks between the stream source switch and the DQ.
-
This means that even though you may not be routing a stream to another switch,
the DQ’s request still puts the stream on the uplink. Therefore, it is important to
account for all streams forwarding to the DQ.
-
The presence of a multicast router with PIM-Sparse configured to handle the multicast
traffic may eliminate or limit this behavior.
-
N-Series Encoders also support separate VLAN tagging of audio and video streams to
allow only certain audio and video streams through an uplink in order to eliminate or
limit this behavior.
4.
Jumbo Frames Enabled
The N2600 Series Encoders/Decoders produce a frame payload larger than 1500 bytes which requires
the switch to have the capacity of handling Jumbo Frames enabled.
5.
TCN Flood Off
TCN flood protocol will cause unnecessary backplane and bandwidth usage when adding or
removing a device on the network. This can cause stream interruptions as the flooding sweeps
through the network.
