Echo with OBI202 using pstn USB dongle

[Gavo]

Hello,

Unfortunately my OBI110 came off worse in a fight with a lightning strike so I set-up a spare 202 with the pstn dongle.
It works fine apart from an annoying echo on incoming calls. I'm presuming there are optimum tx/rx gain settings to stop this issue ?
(impedance is matched to my BT pstn line so I don't believe impedance mismatch to be the problem)

Cheers

Gavin

[ProfTech]

Ouch. This is specifically why I junked a Linksys and bought the 110. The linksys had a horrible echo and the firmware for it was obsolete and no longer supported by Cisco. I never really had any echo to speak of with my 110. It pretty much "just worked" out of the box. I've always wondered about the 200/202 and the USB adapter. About the only thing I can think of that might affect the echo might be the level at which the Obi feeds the phone line. I'm not sure what setting it would be in the 202. Maybe you are hitting the phone line a little too hard. I think the impedance setting is pretty obvious. I think it is either right or wrong. Anyway, good luck. Maybe I should order a spare 110 while they are still available. Problem is, I've been considering the 200 because it has more ITSP slots. I could use one more. 

[Mango]

Looking at Amazon reviews, it seems that two of the six reviewers also report echo.  Though one of the remaining isn't using the device with a POTS line, and at least one seems to suggest he's not using it with an OBi.  So those Amazon reviewers who have echo is more like two in four.

Please keep us updated if you're able to solve this.  Have you raised this issue with Obihai support?  I would be very surprised if they released an inherently defective product.

[drgeoff]

It works fine apart from an annoying echo on incoming calls.

Do you really mean that calls you dial don't have the echo?

[willmw]

I have the same issue.  I contacted support and they recommended I adjust the tx and rx gain settings which I did.  It helps some, but I still have a considerable echo.  For the record, the echo is on any pstn call...incoming or outgoing.

[AndyJ]

Just to add to this... I recently purchased an OBiLINE for use with an OBi200, and hear significant echo. I've been through every ACImpedance setting, and tried adjusting the ChannelTXGain and ChannelRXGain, but cannot get rid of it. Phones plugged into the same jack used by the OBiLINE have absolutely no echo. I can hear the echo even if I connect the OBiLINE to an OBi110's phone port (where there should be an exact 600 ohm impedance match), which completely eliminates the PSTN as a factor.

I've opened a support ticket, so I'm hoping there is some solution.

(I also get very frequent DTMF talk-off with the OBiLINE, but that's another issue...)

[Sophia]

Very sorry to say that it seems a consistent problem with that model After several tickets and VERY HELPFUL but sadly useless Obihai staff support, we decided to go back to our trusted 110 and never looked back. No traces of echos on that one!

[HDFLucky]

Very sorry to say that it seems a consistent problem with that model

Correction. It may be your experience that there is consistent echo, but it is not an intrinsic problem with the device. I have three of these set up in three different locations and never had a bit of echo, even when the gains were set too hot.

[agarciat]

I have the same problem .   I Changed the impedance and it reduce but didn't stop. Have you had any luck with support?

[ProfTech]

Correction. It may be your experience that there is consistent echo, but it is not an intrinsic problem with the device. I have three of these set up in three different locations and never had a bit of echo, even when the gains were set too hot.

Which gain(s) did you turn down and what settings did you end up at? These aren't the first reports of echo I've seen... Just got an Obi 200 and would like to know.

[HDFLucky]

Which gain(s) did you turn down and what settings did you end up at?
... Just got an Obi 200 and would like to know.

Assuming the menu settings are the same in the OBi200 (this thread is about OBi202), see my previous post in this other thread: http://www.obitalk.com/forum/index.php?topic=8402.0

Note that the numbers are logarithmic, not linear; if -3 isn't enough, try -6. Also, make sure you are not testing with a phone in the same room.

[ProfTech]

The other post(s) you reference do not mention use with a PSTN dongle at all. The echo situations I've read about [and experienced with Linksys] specifically relate to PSTN usage. I run a Obi 110 and as Sophia and others indicated the 110 does not experience it. Haven't seen even one post from an Obi 200 or 202 [they run the same firmware] user using the dongle. I don't really want to spend $35 to test it. 

[HDFLucky]

Dongle or not, there are only a limited number of causes for echo:
1. Infrastructure problem - Infrastructure problems include things like wiring defective echo cancelers on the public network, and excessive network latency. There's not much you can do about any of these unless it's a local-loop wiring problem or latency introduced locally.
2. Tx and/or Rx gain set too hot - The solution to gain issues is obvious.
3. Shared IRQ - Not applicable in situations that don't involve the signal path traversing a computer link.

I suppose it's possible that the adapter has an inherent design flaw that introduces echo, but I find that hard to believe. That said, perhaps this posting on Amazon will be helpful: http://www.amazon.com/review/R2Z07KJVGJVAXE/ref=cm_cr_pr_viewpnt#R2Z07KJVGJVAXE

[agarciat]

Impedances should help according to other post i have read. For that, the best it to take it from the following website as it dependnd on the country where the obi is located . http://www.3amsystems.com/World_Tone_Database/Compliance_data
At the moment i have reduce the gain but still with a bit of echo with a ChannelTxGain" -4 ChannelRxGain"-3 (from -2 and -1 factory settings)

[mrjoe]

I experienced echo issues as well as the Disconnect tone not being sent through to the PSTN line.

I'm now back with my trusty OBi110 that has absolutely no echo and also has the relay switch.

[w00dy]

Ive just logged a support ticket for this. For now I've given up on the OBI202 and USB dongle, the echo renders it unusable.

Ive reverted to using the VOIP/FXS/FXO functionality on my Draytek 2830Vn and it works perfectly, using EXACTLY the same connections/configuration that I had with the OBI202. Ive literally just moved the 2x phone connectors and 1x line connector from the OBI to the Draytek. I can also report that it works perfectly using an SPA3102.

So that eliminates phone or PSTN issues as far as Im concerned, leaving only gain or impedance settings as the possible cause. But I have tried pretty much every conceivable permutation.

I would take some persuading there is a not a fundamental issue with the USB dongle.

[Mango]

Please let us know how the support ticket goes.

[BigSkies]

I have the exact same problem in the UK and very interested in a solution.

[eskdale]

Can I add another to this problem in the UK- Have now spent several hours trying different options.

I have two lines one has a Spa3102 on it and that works acceptably well - most of the time there is no echo at all just the odd bit when something changes suddenly on the line.  But the Obi202 with USB PSTN dongle can't get rid of the very annoying echo - tried different impedance settings different cables and even plugged it into the other line that is normally using the 3102 - all to no avail.

Willing to try suggestions - But it does seem a problem - is it a UK only problem or perhaps a batch of PSTN USB dongles

Jon

[mingobi]

Hi Jon and everyone,

When you have echo, is it that you hear yourself? Or is the guy on the other end of the line hearing him/herself?

Bill

Can I add another to this problem in the UK- Have now spent several hours trying different options.

I have two lines one has a Spa3102 on it and that works acceptably well - most of the time there is no echo at all just the odd bit when something changes suddenly on the line.  But the Obi202 with USB PSTN dongle can't get rid of the very annoying echo - tried different impedance settings different cables and even plugged it into the other line that is normally using the 3102 - all to no avail.

Willing to try suggestions - But it does seem a problem - is it a UK only problem or perhaps a batch of PSTN USB dongles

Jon