Rx CRC Error Correlation
Rx CRC CRC Error Erro r Corr elati elation on Transmit problems on one or more remotes may cause CRC errors on the hub line card that is receiving the upstream carrier. CRC errors could be caused by any of a number of problems: a remote transmitting above the saturation point, a bad cable, interference, etc. If the upstream carrier is being received by an iNFINITI line card, you can use the iDirect Rx CRC Correlation feature to identify which remote or remotes are causing the receive packet errors (Rx CRC errors) on the card. This FAQ provides instructions for correlating Rx CRC errors with remote modems in an iDirect Network. It contains the following sections: • • • •
“Determining the Inroute IDs for Your Network” Network” “Enabling Rx CRC Correlation for Your Inroutes” Inroutes” “Connecting to the Protocol Processor Blade” Blade” “Running the CRC Correlation Report” Report”
Note: CRC CRC error checking is a processor -intensive operation. To avoid avoid o verloading t he processes of you r li ne cards, iDirect recommends th at you delete the custom keys t hat enable enable Rx CRC CRC Correlation when you are finished.
Determini Determini ng the Inrou te IDs IDs for Your Netwo Network rk Follow these steps to determine the Inroute IDs for each Inroute being received by a line card with CRC errors: 1. In iBuilde iBuilder, r, righ right-cl t-click ick on the the Networ Network k and sele select ct Compare Configurations from Configurations from the menu.
2. In the Config Configura uration tion Compa Compariso rison n dialog dialog box, box, clear clear the Show Differences Only check Only check box.
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Enabling Rx CRC Correlation for Your Inroutes 3.
Examine the Latest pane to determine the Inroute IDs for the Inroutes in your Network. Inroute IDs are displayed in the format INROUTE_#, where # represents the ID of the Inroute. Note the ID of each Inroute.
Enabling Rx CRC Correlation for Your Inroutes Once you have determined the Inroute IDs, follow these steps to enable Rx CRC correlation for the Inroutes: 1.
In iBuilder, right-click on the Network in the iBuilder tree and select Modify->Item from the menu.
2. Click the Custom tab.
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Enabling Rx CRC Correlation for Your Inroutes 3.
Enter a network-level custom key in the following format:
[ I NROUTE_ #] di sabl e_l ock = 0 where # is the Inroute ID determined in the previous step. If you have multiple Inroutes in the Network, you need to create a custom key for each. For example:
[ I NROUTE_1] di sabl e_l ock = 0 [ I NROUTE_2] di sabl e_l ock = 0 etc.
4.
Click OK to save your changes.
5.
Right-click the Network in the iBuilder tree and select Ap pl y Co nf ig ur ati on ->Netw or k from the menu.
Repeat this process for any other Networks you want to check.
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Connecting to the Protocol Processor Blade
Connecting to the Protocol Processor Blade Once you have configured the custom keys, follow these steps to connect to your protocol processor blades to determine which remotes are causing the errors. Follow these steps to connect to a blade: 1.
Using a terminal emulator (such as PuTTY), log on to your NMS server using SSH.
2.
From the command line of the NMS server, enter the following command to log onto a blade: telnet 13255 where IP_Address is the address of the protocol processor blade.
3.
Log on to the blade with Username: admin.
Running the CRC Corr elation Report Once you have logged on to a protocol processor blade, follow these steps to view the Rx CRC errors for the Networks configured to use the blade. 1.
From the command line, enter the command sarmt to access the sarmt functions on the blade: > sarmt;
2.
Enter the net list command to determine t he networks available on this blade. You will see a list of valid networks, as in the following example: > net list
Val i d Net works are: 1 4 6 3.
Enter the net command to select the Network you want to examine. For example, > net 1
NETWORK 1 4.
Enter the crc report command to see the number of CRC errors generated by each remote over time. The crc report command has several forms shown in the syntax below: > crc report
Usage: crc r epor t {dat a| acq| al l } [ r eset ] 5.
Enter the following command to see a count of data CRC errors per remote: > crc report all
3100. 3235 3100. 3502 3100. 4382 3100. 4463 3100. 4656 3100. 7249 3100. 8963 3100. 9162
: : : : : : : :
DATA DATA DATA DATA DATA DATA DATA DATA
CRC CRC CRC CRC CRC CRC CRC CRC
[ 1] [ 5818] [ 20] [ 3] [ 11] [ 1369] [ 1] [ 1]
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Running the CRC Correlation Report You can clear the counts by entering: > crc report all reset 6.
Repeat steps 3 through 5 for each Network on current blade, or enter the following command to see all CRC errors for all Networks on the blade: > net * crc report all
If you have more protocol processor blades to check, execute this procedure again, beginning with the instructions in the section “Connecting to the Protocol Processor Blade” on page 4. When you have finished, iDirect recommends that you delete the custom keys you configured for your Network(s) and reapply the changes.
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