Specifications

Appendix A
47
DD
Digital Diagnostics is an extended function of SFP modules that is specified in MSA (Multi-Source Agreements).
Standard information that can be read from SFP includes the manufacture's name, model and serial number of the
SFP. DD includes real time values for transmit and receive power and temperature within the SFP.
Examples of SFP without and with DD function.
Port Active
Use this pull-down to select whether to enable or disable the state of the media converter. When disabled, all
LEDs on the unit and in the Web GUI will be extinguished. This function is not allowed when managing the remote
converter and will be 'grayed out'. To disable a link, the local or 'in-chassis' converter must have its port disabled.
Operation Mode
This pull-down chooses between switch mode and converter mode. When the media converter works in
'switch mode' mode, it does not begin to forward a packet to a destination port until after the entire packet is
received. The latency therefore depends on the packet length. The maximum packet length supported is up to
2046 bytes in this mode. Different from a normal switch chip, the media converter's chip supports forwarding
IEEE802.3x pause frames. In 'switch mode' the MC operates with a 'store & forward' method that supports a 1K
MAC address table. The UTP side may be 10 or 100 speed and in full or half duplex, while the fiber side runs in
100Base, full duplex.
In 'converter mode', the MC operates with low latency. The transmission does not wait until the entire frame is
received, but instead it forwards the received data immediately. Both transceivers (UTP and Fiber) in the MC are
interconnected via the OAM (Operation, Administration and Maintenance) engine while the internal switch engine
and data buffer are not used. The MC filters OAM frames and supports 9KB jumbo packet in this mode. Again, the
switch engine is disabled in this mode and the UTP must be 100Base, Full Duplex to match the fiber's 100Base-
Full. The default setting is switch mode for this media converter.
Link Fault Pass Through
This pull-down chooses between enabling and disabling the LFP function. The LFP function is explained in
A.1.2. The default is disabled.
Auto Laser Shutdown
This pull-down chooses between enabling and disabling the ALS function. The default is disabled.
Loopback Test
Use this pull-down to activate the non-intrusive OAM loopback test function. Remember to turn it off when
finished testing.
In Band Management
This pull-down is used to enable or disable the OAM (In Band Management) function. Once disabled the OAM
maintenance frames will no longer be transmitted, while received frames will be ignored. Monitoring and managing
of the remote converter will be disabled. The default setting for this function is enabled.