Transmitting Bert Data - Cisco 678 Installation And Operation Manual

BERT Testing (Cisco 675, Cisco 675e and Cisco 676 only)

Transmitting BERT Data

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Cisco 600 Series Installation and Operation Guide
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Cells are generated by the HP and terminated by the Cisco 675s in the downstream
direction, and vice versa for the upstream direction. The HP can only check BERT
data on one channel at a time. It is therefore necessary to manually walk through
every channel to verify data integrity. The BERT test can be performed without
the HP test set if the Cisco 6100 NIU is physically looped back at the OC3 port.
The following are the procedures for transmitting BERT data. Note that all
pertinent tests will be initiated from the Optical Line Interface Card, and not a
Cell Processor.
Configure the load generator (truck icon) to send S-PRBS9 data to each CPE on
VPI X / VCI X. Starting with channel 2 on the load generator, set up a connection
using VPI 1 / VCI 32. Continue with channel 3 as VPI 1 / VCI 33 and so on until
the number of channels that need to be tested are accounted for.
Set the contents of each cell to S-PRBS9 with AAL1 enabled. All channels can be
done at once by highlighting all of the channels and then setting the contents.
AAL1 provides sequence numbers to determine if cells are being dropped.
Set the bandwidth to the desired downstream rate. Again, all channels can be
highlighted and changed simultaneously. This rate should be slightly lower than
the trained rate (for example, 1.4M).
Configure the Cisco 6100 or Cisco 6260 to set up connections from the NIs OC3
to the CPEs. Use the same connection parameters (VPI/VCI) that were used to
configure the load generator.
Verify that no other cell generation sources are active on the HP and that the laser
is turned on.
Compile the load generator and data will start flowing to the NI, through the Cisco
6100 or Cisco 6260 and out to the CPEs. Every time a parameter is changed in the
load generator, it is necessary to compile for the change to take effect.
The CPE should now be receiving BERT data.
Chapter 6 Troubleshooting
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