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Unable to dial on land line when Internet connectivity was down

Started by bheiser, January 04, 2012, 07:11:58 PM

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bheiser

Hi OBi users ...  I've been using my OBi 110 for a few weeks, and have been generally happy with it.  I have it connected to the Internet via my cable provider, and also have a landline connected to the line port.

Today I had a situation where I lost connectivity to the Internet due to a router/cablemodem issue.  During this outage, I was unable to dial out on the landline using **8nnnnnnn as I normally can.  Dialing **8 was very slow to break the dialtone, and the call never went through.

I guess I should have tested an inbound call, too, but didn't think of that at the time.

Is this a known issue, or is there a configuration option I can set to ensure I can always maintain landline voice connectivity regardless of the status of my Internet connection?  Sure, I can unplug the phone line from the OBi and connect directly to the telephone in these situations, but that doesn't seem like an optimal solution :).

Thanks!

RonR

I don't experience that here.  With the Ethernet cable unplugged and the power LED blinking to indicate a loss of Internet connectivity, I can still dial **8 + number with nothing abnormal noted and the call goes out to the PSTN line.

If you remove power from the OBi, the PHONE Port will be directly connected to the LINE Port without making any wiring changes.

Stewart

The OBi resets if it loses and regains its local network connection.  In your case, this could happen if your cable modem is also a router (and the OBi is directly connected to it), or if your router is somehow rebooting in response to lost Internet connectivity.  What make/model modem do you have?  Separate router, if any?

If you can't avoid the trouble, it may be easier to regain access to the phone line, by removing power to the OBi.  There is a relay that automatically connects the PHONE and LINE ports when power fails.

To simulate the problem for troubleshooting purposes, try disconnecting the coaxial cable from your modem.

bheiser

Thank you both for your quick responses.  I actually have the Obi device connected to a dumb switch, which then connects to an Asus RT-N16 (acting as a router) running Tomato firmware.  The RT-N16 connects to the cable modem.

BTW, as one quick test, I just did the following:

- dialed **8<cellphone-number>
- answered the cell phone and let it sit
- unplugged the power from the Obi
- the call dropped

Is there a configuration parameter that controls the relay to maintain the phone/line port connection when power fails?

I did a second test which proved more promising:
- dialed **8<cellphone-number>
- answered the cell phone & let it sit
- unplugged the network uplink from the router (thereby severing Internet connectivity)
- the voice call remained active
- reconnected the network cable, restoring normal connectivity (and the call stayed active).

and another test:
- unplugged network uplink from router
- dialed **8<cellphone-number>
- this call went thru just fine

The symptoms I encountered earlier may well have been a corner case because it turned out both the cable modem AND the router had to be rebooted to regain Internet connectivity, the first time I've hit that particular scenario in this configuration.

Thanks again!

RonR

Quote from: bheiser on January 04, 2012, 08:55:09 PM
BTW, as one quick test, I just did the following:

- dialed **8<cellphone-number>
- answered the cell phone and let it sit
- unplugged the power from the Obi
- the call dropped

Is there a configuration parameter that controls the relay to maintain the phone/line port connection when power fails?

It doesn't work that way.  The relay is normally engaged when the OBi is powered up, connecting the PHONE Port and LINE Port jacks to the appropriate interfaces in the OBi.  When the OBi loses power, the relay de-energizes, disconnecting the OBi and making a direct connection between the PHONE Port and the LINE Port jacks.  There's probably enough break time in the changeover that the CO sees a hangup.

bheiser

OK, I may have misinterpreted your original comment about the relay & the line port.  So the bottom line is if the OBi doesn't have power, I can't make a call - there's no dialtone from the Obi of course.  And if it loses power during a call, the call drops & I can't redial (again, no dialtone).  This all makes sense :).

What did you mean by your original comment though here?

> If you remove power from the OBi, the PHONE Port will be directly connected to the LINE Port without making any wiring changes.



RonR

The relay in the OBi is a failsafe.  If the OBi doesn't have power, the telephone connected to the PHONE Port jack is connected directely to the LINE Port jack which has your PSTN line plugged into it, allowing you to make outgoing calls using your PSTN provider as if the OBi never existed.

Unfortunately, any call that's going through the OBi's electronics will probably be lost when the OBi loses power and the relay changes over to the direct connection, due to the time it takes the relay to mechanically change positions.

Stewart

If the OBi has no power, the relay is de-energized and should connect the PHONE and LINE ports together, so you can get dial tone from the CO and make or receive calls.

However, at the time that OBi loses power, there is probably about 200 milliseconds during which neither the electronic nor the relay path are active, so a call in progress will be dropped.

Edit: RonR beat me to it.

bheiser

OK - I did understand you correctly then :) but my OBi isn't behaving the way you described.

If I remove power from the OBi, the Phone gets no dialtone, so I'm unable to place or receive calls... so it doesn't appear the relay is working as you described.

Hmmm ...

RonR

Quote from: bheiser on January 05, 2012, 05:21:12 PM
If I remove power from the OBi, the Phone gets no dialtone, so I'm unable to place or receive calls... so it doesn't appear the relay is working as you described.

That's definitely the way the relay is designed and supposed to work.

Are you sure you can place calls through the LINE Port successfully by dialing **8 + number (with the OBi powered up, obviously).

bheiser

Yes - definitely - I've been making calls all day by dialing **8 + number.  It's been working great.

Just now I tested the relay functionality again just to be sure what I'm telling you is accurate.  So I did this:

- with everything normal I unplugged the power from the OBi
- checked for dialtone on the phone - there was none
- plugged in power to the OBi and waited for it to boot up
- checked dialtone - dialtone was present

Maybe I should log a ticket with OBiHai, eh?

RonR

The dialtone you hear when the OBi is powered up comes from the OBi itself, not the PSTN Line.

It sure sounds like your failsafe relay is not functioning properly.

bheiser

Quote from: RonR on January 05, 2012, 05:42:50 PM
The dialtone you hear when the OBi is powered up comes from the OBi itself, not the PSTN Line.

Yup, this is what I thought.

Thanks for the heads-up on the relay issue ... I will contact OBiHai to see what they think.

poulsone

My new OBi110 does not have a (functioning) relay.  I hear no sound on power-up/down, and the LINE and PHONE are not connected together when powered off.

The official reply from support@obihai.com:
"The hardware relay is no longer in the OBi110 device functionality"

Does anyone now if this change is simply not soldering the relay in (so I can add it myself), or has the circuit board been revised to omit the relay circuitry?

Eric

RonR

Quote from: poulsone on January 24, 2012, 12:18:54 PM
Does anyone now if this change is simply not soldering the relay in (so I can add it myself), or has the circuit board been revised to omit the relay circuitry?

It's still listed as a feature in the OBi110 Data Sheet:

Logical FXS to FXO Relay          For Service Continuity in Case of VoIP Service Failure

infin8loop

Quote from: RonR on January 24, 2012, 12:30:21 PM
Quote from: poulsone on January 24, 2012, 12:18:54 PM
Does anyone now if this change is simply not soldering the relay in (so I can add it myself), or has the circuit board been revised to omit the relay circuitry?

It's still listed as a feature in the OBi110 Data Sheet:

Logical FXS to FXO Relay          For Service Continuity in Case of VoIP Service Failure


When asked for an official comment, the Forum Moderator had this to say ....

http://www.youtube.com/watch?v=CQFEY9RIRJA

or

ChaChing! ... We're making another 10 cents per unit by not including a relay.
"This has not only been fun, it's been a major expense." - Gallagher

RonR

Quote from: infin8loop on January 24, 2012, 04:19:05 PM
ChaChing! ... We're making another 10 cents per unit by not including a relay.

I hope that's not the case.  The fail-safe relay is an important feature to those of us who rely on the PSTN line for our 911 service.  I hope it was just a miscommunication of some sort.  I guess we'll know if anyone else turns up with a recent OBi110 purchase who can't access the LINE Port without power.

jalapeno19104

I just received an Obi110 device today from Amazon that does not appear to have the relay installed. I have an email in to support asking about it. Hardware version is reported as 3.4.