MRV Communications EM316-2SFP - page 11

EM316-2SFP User Guide
P/N 1259003-001 Rev C3 2
2.1.2 Loopback
The EM316-2SFP module supports loopback either by DIP switch setting or controlled through
the CLI or SNMP software settings. For software control the Loopback DIP switch must be set
to OFF. It the Loopback switch is ON, it cannot be over-ridden by software.
Loopback is one way to assure that the fiber optical communication path is valid and error free.
Packets sent over a short-circuit link should be received by the sender without any modification
to the original data packet.