Commissioning
62/90
7.8
Auto-crossover and port-switching
In a system with for example one netANALYZER device and two RTE
devices, the assignment of port 0 and port 1 or port 2 and port 3 can
change between different test runs. This is due to the auto-crossover
feature of most RTE systems. For auto-crossover the cable assignment by
the devices is given randomly. The assignment of the lines as a
"transmission line" or "receiving line" is random.
Example
Figure 17: Example - Auto-Crossover and Port-Switching
For the 2nd measurement in this example the reception of the Ethernet
frames is wrong. The port numbers in the frames were exchanged.
If both devices use auto-crossover, there is the possibility that port 0 and
port 1 will be exchanged for subsequent measurements. This is also true
for port 2 and port 3.
Schematic Design of a
Figure 18: Design of a TAP, at the right Side Ports of Device 1 and Device 2 exchanged
The schematic design of a TAP makes evident which effects an
interchange of the lines of the two devices has.
Workaround
A workaround is possible, by drawing conclusions from the records of two
consecutive test runs. In the records for the second test run compared with
the first test run, modified port numbers can be found.
netANALYZER device NANL-B500G-RE | Installation, operation and hardware description
DOC091110UM26EN | Revision 26 | English | 2019-07 | Released | Public
© Hilscher 2007-2019
