Link Loss Carry Forward (LLCF)
The Radiance SONET single interface line card incorporates LLCF for trouble- shooting a remote connection. With LLCF, the ports do not transmit a signal until they receive a signal from the opposite port. For example, if a line card loses link on Port 2, the card will not transmit link pulses out of Port 1.
The diagram below shows a typical network configuration with good link status using SONET line cards for remote connectivity.
Management Switch/Hub | SONET | SONET | Switch/Hub Management | ||
Station | w/SNMP | Line Card | Line Card | w/SNMP | Station |
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| Remote |
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| Cable |
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LED lit = established link | LED unlit = no link |
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If a connection breaks, the line cards carriy that link loss forward to the switch/ hub which generates a trap to the management station. The network administra- tor can then determine the source of the problem.
Management Switch/Hub | SONET | SONET | Switch/Hub Management | ||
Station | w/SNMP | Line Card | Line Card | w/SNMP | Station |
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| Broken |
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| |
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| Remote |
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| |
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| Cable |
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| |
| Link Loss Carried Forward | Link Loss Carried Forward |
| ||
LED lit = established link | LED unlit = no link |
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| ||
Management Switch/Hub |
| SONET | SONET | Switch/Hub Management | ||
Station | w/SNMP | Line Card | Line Card | w/SNMP | Station | |
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|
| Remote | Broken |
| |
|
|
| Cable |
| Cable |
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|
| Link Loss Carried Forward |
|
| ||
LED lit = established link | LED unlit = no link |
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| |||
Radiance SONET Single Interface Line Cards 11
