CANOGA PERKINS N525 Ethernet Termination Service Unit - Manual (Page 85)

N525 Ethernet Termination Service Unit 4-9
Figure 23 - Local-Remote Loopback Mode
• Remote-Local Mode
Remote-Local Mode loops data received on the User Port Rx through the FPGA to the
User Port Tx. Data is not sent out the remote Extension Port Tx and incoming data on
the remote Extension Port Rx is ignored. See Figure 24. To set this mode, set the
Loopback State for the Remote module to Local.
Figure 24 - Remote-Local Loopback Mode
• Remote-Remote Mode
Remote-Remote Mode loops data received on the Extension Port Rx through the Local
User PHY to the Extension Port Tx. Data is not sent out the local User Port Tx and
incoming data on the local User Port Rx is ignored. See Figure 25. To set this mode,
set the Loopback State for the Remote module to Remote.
Figure 25 - Remote-Remote Loopback Mode
For loopbacks, the N525 uses a unique MAC address, the Loop Test MAC Address, which
is displayed on the Loopback Setup Screen. For details about using the software and
accessing the Loopback Setup Screen, see Chapter 4. When in loopback mode, the N525
filters the incoming packets to identify test packets identified by the MAC address.
The N525 is configurable to swap the origination and destination MAC Addresses and to
Recalculate the looped frame’s CRC. Test packets are returned to the source according to
the selected options.