Planet Technology SVC2540 - Manual (Page 25)

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When multiple CoS schemes are enabled, the data packet is treated as the high priority as long as any one of three
CoS schemes is mapped to “high”.
Take the following example for detail explanation.
If a port is set as a low priority port, when it receives a packet, which embeds with high priority VLAN tag, this packet
will be forwarded as a high priority packet. In the other words, the priority of a packet would be set to high if any of
two CoS schemes is interpreted as the high priority.
Figure 4-10 Class of Services Configuration screen
LLR Mode - Link Loss Return (LLR)
The fiber ports of the Web Smart Media Converter have been designed with an LLR function for troubleshooting a remote
connection. LLR works in conjunction with LLCF.
When LLR is enabled*, the port’s transmitter shuts down when its receiver fails to detect a valid receive link. LLR should
only be enabled on one end of the link and is typically enabled on either the unmanaged or remote device.
The diagram below shows a typical network configuration with a good link status using Smart Media Converter for remote
connectivity. Note that LLR is enabled as indicated in the diagram.
Management Switch/Hub Media Media Switch/Hub Management
Station w/SNMP Converter Converter w/SNMP Station
● LED lit = established link ○ LED unlit = no link
If one of the optical conductors is bad(as shown in the diagram box below), the converter with LLR enabled will return a
no-link condition to its link partner. With LLCF default, the no-link condition is carried forward to the switch/hub where a
trap is generated to the management station, and the administrator can then determine the source of the loss.
LLCF is
default LLCF is
default
Fiber
Cable