5 replacing modules, 6 data transmission errors, 7 dial-up connection to standalone modem – CANOGA PERKINS 2361 T1 Modem User Manual

Page 54

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The EdgeAccess Universal Chassis System

2361 Modem Users Manual

6-4

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, and use as an external BERT. 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 Standalone Modem

The Dial-up connections pertain to standalone 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 2361 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. Confirm or verify that the speeds of the 2361 modem and the dialup modem are the same.

If not, correct them.

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