RuggedCom RS1600 ユーザーズマニュアル

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Chapter 7 – Configuring Multicast Filtering 
Troubleshooting 
Problem One 
•  When I start a multicast traffic feed it is always distributed to all 
members of the VLAN. 
Is IGMP enabled for the VLAN?  Multicasts will be distributed to all members of 
the VLAN unless IGMP is enabled. 
Problem Two 
•  Computers on my switch receive the multicast traffic just fine, but 
I can’t get the stream through a connected router. 
Is the port used to connect the router included in the Router Ports parameter of 
the VLANs menu?   
To determine whether the multicast stream is being delivered to the router, run the 
Ethernet Statistics menu View Ethernet Statistics command.  Verify that the 
traffic count transmitted to the router is same as the traffic count received from 
the multicasting source. 
Problem Three 
•  The video stream at one of my end stations is of pretty poor 
quality. 
Video serving is a resource-intensive application.  Because it uses isochronous 
workload, data must be fed at a prescribed rate or end users will see glitches in the 
video.  Networks that carry data from the server to the client must be engineered 
to handle this heavy, isochronous workload.  
Video streams can consume large amounts of bandwidth.  Features and capacity of 
both server and network (including routers, bridges, switches, and interfaces) 
impact the streams.  
You should not exceed 60% of the maximum interface bandwidth.  For example, if 
using a 10 Mbps Ethernet, you should run a single multicasting source at no more 
than 6 Mbps, or two sources at 3 Mbps.  
Router ports will carry the traffic of all multicast groups, so it is especially 
important to consider these ports in your design 
Note that multicasting will definitely introduce latency in all traffic on the 
network.  Plan your network carefully in order to account for capacity and latency 
concerns.
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