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Transmission Quality Issues

Transmission Quality Issues

Transmission Quality Issues

Several months ago I installed a UCx 50 switch in a small business that has only four analog lines. The UCx they sent me did not have the onboard CO ports. Instead, they sent me a Grandstream modem, which plugs into the UCx 50. From day one I've had issues with the transmission quality. Specifically, any time someone inside the office is talking on one of the lines, they hear a constant hissing or feedback in the background, but only while they're actually speaking. As soon as they stop speaking, the hissing sound stops. Start speaking again, the hissing starts again. So far nobody has been able to help me, and my customer is close to packing up and returning the whole darn thing. Any suggestions? I'd really like to get this cleared up, because I really like the product, and would like to continue selling it. Thanks!

RE: Transmission Quality Issues

Hi dp1234
Did u do an impedance auto- detect test
on the Grandstream FXO gateway ?

Sideline Telephone Service Inc.
Canadian - Reseller

RE: Transmission Quality Issues

Not sure how this is done. I should also mention that the party on the other end of the line (outside of the office) does not hear any problem.

RE: Transmission Quality Issues

Hi dp1234
This is from the grandstream site :
The user can only test the parameters for only one of the PSTN lines at the
same time. In all cases please enter the telephone numbers as if the lines were to
dial each other locally.
For the AC Impedance Test we only need to select the line to be tested by clicking on
the AC impedance box corresponding to that line, telephone numbers are optional.
Remember that the AC impedance test is usually used to reduce the echo that might
be present in the line.
To perform the test, please select the line you want to test and the desired test to be
performed. Enter the information for this line as well as a second line if necessary.
Then click on the update button and then reboot. Log back in and now you should
see the information for the line selected as well as the check box already marked
already there. Go ahead and start the test now, please wait a few minutes until the
test is done.
It is not required to enter a telephone number when testing for impedance, as the
system does not place any actual calls for the test.
If you log into the Web Interface while the test is running will not interrupt the process.
This is under line analysis
Apply test results automatically - yes
Apply test results to all ports - yes

I hope this helps

Sideline Telephone Service Inc.
Canadian - Reseller

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