CANOGA PERKINS 2461 E1 Modem - Manual (Page 56)

EdgeAccess Universal Chassis System
6.5 Replacing Modules
When you have replaced a Line Interface Module or an entire modem, possible configuration
errors may surface, turning the CFG indicator red. This condition may most likely be the result of
software version incompatibility. You can verify this by going to the System Alarms screen where
the Configuration Error line will show "OS". In order to correct this, proceed to Chapter 8 of this
manual, Upgrading the Modem Software and update the modems with the same software
versions. In a redundant system, all four modems must have the same software versions. This can
be accomplished with the Copy Source Modem to Destination modem command on the Software
Upgrade Screen.
6.6 Data Transmission Errors
Before trying to troubleshoot data transmission errors, verify that this is not a fiber cable problem.
Perform step 6.2 above. Next verify that the Link Self Test does not show any errors. This can be
verified by checking the TST LED on the front panel. If it is OFF, proceed by verifying the Link
Self Test status on the System Alarms screen.
Loopback tests are the best place to start troubleshooting transmission data errors. Proceed to the
Diagnostic screen to perform loopback tests. Do a remote BERT loopback (requiring a remote
modem for activation), or use an external BERT if a test set is available.
If the results are inconclusive, replace the composite link with a single Rx to Tx cable connection
that is known to be good. If the results are still inconclusive, create a physical loopback with real
hardware, setting each modem loopback mode to "OFF."
6.7 Dial-Up Connection To A Stand Alone Modem
The Dial-up connections pertain to stand alone modems only.
1. Confirm or verify that the MDM/TRM switch (on the modem front panel) is set to the
MDM position. If not, correct it.
2. Confirm or verify that the cable between the 2461 modem and the dial-up modem is a
straight-through cable and not a crossover cable.
3. The initialization string must include hardware flow control and data compression
enabled.
4. Verify that the speeds of the 2461 modem and the dialup modem are the same. If not,
correct them.
2461 Modem User Manual 6-4