User Manual

Chapter 13 ● Loopback testing backhaul links
162 Release 2.0, 910056 Rev01d
Looping back Ethernet backhaul links
This section explains how to install the physical loopbacks when Ethernet backhaul links are used. If the
Ethernet backhaul cable is connected to a patch panel (or another passive, pass-through device), you can
install the loopback at the far side of it and thereby include the patch panel in the test.
Because Airvana does not specify the Ethernet cable/connector types, the details of looping back the
Ethernet cables are site-dependent. Typically, Ethernet backhaul cables installed into the backhaul punch
block have an RJ-45 jack at the far-end. This section provides the pin-out for the RJ-45 jack.
1. If the Ethernet at the point of the loopback installation has an RJ-45 connector on the far end, build a
loopback jack using the pin-out in Table 23
.
2. If the Ethernet backhaul(s) have a different connector, build a loopback jack as appropriate.
3. Install the loopback connectors onto the far end of each Ethernet cable.
NOTE
You cannot loopback the Ethernet at the far side of most network
devices, including switches, routers, and FRADS.
NOTE
• Physical loopbacks are created by physically
connecting the positive transmit wire to the positive
receive wire and connecting the negative transmit
wire to the negative receive wire.
• Loopbacks must be installed on all Ethernet backhaul
cables. There is one Ethernet backhaul cable on
non-redundant systems; there are two on redundant
systems.
Table 23 RJ-45 Ethernet pin out for loopback
RJ-45 wire Description For loopback...
1 transmit, positive connect to wire 3
2 transmit, negative connect to wire 6
3 receive, positive connect to wire 1
4 unused
5 unused
6 receive, negative connect to wire 2
7 unused
8 unused