NV6310/NV6355 - rx/tx gain on FXS ports for modem passthrough

[Anonymous]

For the few times that credit card/fax machines give trouble using these, what do you do if an outside loop in unavailable? I have read in the past with similar products that reducing the tx and rx gain could help. I just was not sure if this applied to these models with the later software. 

[Anonymous]

Anybody have an idea for this one? I would think the tx and rx gain would apply to the TA900 series as well.

[jayh]

This applies to the TA900 but I suspect the Netvanta units are similar.  Credit card machines rarely give trouble for us. Postage meters are our biggest headache.  Make sure you have modem passthrough enabled, call waiting disabled. 

Generally reducing TX and RX gain to -6 dB seems to help.  Trial-and-error impedance setting may also help, try both 600 real and 600 complex and possibly the 900 settings. 

[Anonymous]

Brentm,

Thanks for posting!   As Jayh mentioned, reducing gain and trying different impedance settings can often increase reliability.  You may want to see our guide on fax and modem calls, Configuring and Troubleshooting Fax and Modem Calls in AOS .  This guide goes over our general recommendations and offers some tips which may help you.  If you continue to experience issues, you may need to create a support ticket at Adtran by calling 888-423-8726.

Thanks!

David

[Anonymous]

Brentm,

I went ahead and flagged this post as "Assumed Answered".  If any of the responses on this thread assisted you, please mark them as Correct or Helpful as the case may be with the applicable buttons.  This will make them visible and help other members of the community find solutions more easily.  If you still need assistance, I would be more than happy to continue working with you on this - just let me know in a reply.

Thanks!

David