Difference between revisions of "PRI"

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#Always be sure to check that the settings for the card match what the provider wants. (Switch type is a big one).
 
#Always be sure to check that the settings for the card match what the provider wants. (Switch type is a big one).
 
#If you see HDLC Abort of Primary D-Chan, you most likely have a timing slip on the PRI.  Replacing the cat-5 the provider usually uses with T1 individually shielded pair wiring often times helps with this, as well as potential echo on the lines.
 
#If you see HDLC Abort of Primary D-Chan, you most likely have a timing slip on the PRI.  Replacing the cat-5 the provider usually uses with T1 individually shielded pair wiring often times helps with this, as well as potential echo on the lines.
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===Echo===
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If you are experiencing echo on your PRI lines, here are a few things you can try modifying:
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*LBO - By default LBO is set to 0.  We have found its a good idea to try -7.5.  If this does not work, contact the provider and see if they can tell you how far the dmark is and what to set the LBO to.  If none of the settings work, set it back to 0.
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*Cabling - Most of the time the provider will install the PRI with cat5 cabling.  While this can work, we have found that installing T-1 Cabling (individually shielded pairs) has in the past alleviated echo issues.  The reason why is that cat-5 is not really rated to push the voltage needed for a PRI, and without the pairs being shielded themselves, bleed over is possible.
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 +
*Echo Cancel Algorithm - Changing this from MG2 to OSLEC has helped eliminate echo in certain installs.
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*Echo Training - Increasing this from the default 800 to 1200 has eliminated echo on installs in the past.

Revision as of 20:44, 30 August 2013

Troubleshooting a PRI

  1. Always be sure to check that the settings for the card match what the provider wants. (Switch type is a big one).
  2. If you see HDLC Abort of Primary D-Chan, you most likely have a timing slip on the PRI. Replacing the cat-5 the provider usually uses with T1 individually shielded pair wiring often times helps with this, as well as potential echo on the lines.

Echo

If you are experiencing echo on your PRI lines, here are a few things you can try modifying:

  • LBO - By default LBO is set to 0. We have found its a good idea to try -7.5. If this does not work, contact the provider and see if they can tell you how far the dmark is and what to set the LBO to. If none of the settings work, set it back to 0.
  • Cabling - Most of the time the provider will install the PRI with cat5 cabling. While this can work, we have found that installing T-1 Cabling (individually shielded pairs) has in the past alleviated echo issues. The reason why is that cat-5 is not really rated to push the voltage needed for a PRI, and without the pairs being shielded themselves, bleed over is possible.
  • Echo Cancel Algorithm - Changing this from MG2 to OSLEC has helped eliminate echo in certain installs.
  • Echo Training - Increasing this from the default 800 to 1200 has eliminated echo on installs in the past.