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Incoming calls on pots line port not ringing through to the phone.

Started by gary-gary, August 03, 2013, 08:06:20 AM

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ianobi

I'm surprised that the OBi does not detect ringing at the low setting that you tried. I wonder if the OBi is detecting each burst of ringing, but for some reason thinks the PSTN call is disconnecting after that burst, then sees another burst of ringing followed by disconnection etc.

Keep the ring detect settings etc low and change this:

Physical Interfaces > LINE Port > RingDelay: from 4000 to 0

If the above theory is true, that might get some sort of ringing through to the phone.

With RingDelay at "0", next try to disable every possible method of "PSTN Disconnect Detection". If any of this works we can add some back in later.

As the OBi works at your home, I can only think that there is something very weird about the PBX.

Shale

Quote from: gary-gary on August 29, 2013, 05:19:37 AM
Do we need to give up on this and get 2-line phones, one line for the OBi and one line for the PBX?

Presuming that you cannot get changes made to the PBX, pretty much Maybe. Yet what confidence do you have that the 2-line phone will recognize the ring? However your parents may be as well off just using a separate phone for the PBX line to provides the ringing sound.  The PBX line could also be connected to the OBi. What calls come in on the PBX line anyway-- just the neighbors and the doorbell?

Recapping, the main symptom is that incoming calls on the PBX are not recognized by the OBi110. Remind me. Do outgoing calls work if you  dial **8 and wait for the PBX dialtone  before proceeding? Can you dial **8 to pick up an incoming call from the line if you somehow knew that the call was coming in?

Taking a multimeter to your parents place could identify what is up, but it is moot if you cannot do anything about it. It could tell you why the OBI and answer machine don't work well if you are curious.

gary-gary

Quote from: Shale
What calls come in on the PBX line anyway-- just the neighbors and the doorbell?

The PBX line IS their new main phone line.  They notified friends, family, banks, etc of this new number when they moved to the retirement home.  We decided to port their old number to GV, for several reasons... they had had the number for 40-years, and the new number is subject to regional tolls, etc.

The PBX line is also tied into wall mounted units in each room for emergency access and even one unit which notes if there is any activity in the apartment.

Quote
Recapping, the main symptom is that incoming calls on the PBX are not recognized by the OBi110. Remind me. Do outgoing calls work if you  dial **8 and wait for the PBX dialtone  before proceeding? Can you dial **8 to pick up an incoming call from the line if you somehow knew that the call was coming in?

When dialing out through the OBi110, # will select the analog (PBX) phone line and outgoing calls can be placed.  GV works fine for both incoming & outgoing calls.  The problem has been that incoming calls on the analog (PBX) phone line are not passing through the OBi110 to the attached phone.

We tried a **8 during an incoming call with no success. :-(

The current workaround has been all the phones but one are connected to the PBX line, and one phone is on the OBi.

-gary

gary-gary

Quote from: ianobi
I'm surprised that the OBi does not detect ringing at the low setting that you tried. I wonder if the OBi is detecting each burst of ringing, but for some reason thinks the PSTN call is disconnecting after that burst, then sees another burst of ringing followed by disconnection etc.

Keep the ring detect settings etc low and change this:

Physical Interfaces > LINE Port > RingDelay: from 4000 to 0

If the above theory is true, that might get some sort of ringing through to the phone.

With RingDelay at "0", next try to disable every possible method of "PSTN Disconnect Detection". If any of this works we can add some back in later.

As the OBi works at your home, I can only think that there is something very weird about the PBX.



There is something indeed very wierd about the PBX!

OK, my parents & I have spent a lot of time fiddling with settings... and we've had some success!!  :-))))

Give me a bit of time to review my notes and try to summarize things... it appears that 5-parameters may be involved.

-gary

gary-gary

OK... here is the rough sequence of events... I'm leaving lots out, only because of the many many setting we were playing with.

All of the following parameters (except 1) are on the Physical Interfaces > Line Port page.

RingDelay: 4000  -->  0
RingThreshold: 40-49  -->  19-23

The phone rang!!!  When picking up the phone, one hears a dial tone, and then the phone starts to ring again when hung up!

Further reductions in RingThreshold and returning it to the default does not change this behavior.

RingDelay: 0
DetectCPC: no
DetectPolarityReversal: no
DetectFarEndLongSilence: no
DetectDisconnectTone: no

Still as before... the phone rings, hear dial tone, rings again upon hang up.

Settings as above, but changed,
TipRingVoltageAdjust: 3.5V  -->  3.2V

Still as before... the phone rings, hear dial tone, rings again upon hang up.

Settings as above, but tried several additional settings for,
RingDelay: 0  -->  1000  -->  500

NO RING!!

Settings as above, but changed
RingDelay: back to 0
RingValidationTime: 256  -->  100

This one was odd, and non-repeatable.  I called, the phone rang, was answered, I heard "hello" then the phone was physically dropped and hung up.  We could not repeat this apparent success.

Added an additional change into the above mix,
RingIndicationDelayTime: 512  -->  256

Still as before... the phone rings, hear dial tone, rings again upon hang up.

Hunting for additional parameters to change, I found another CPC setting on the Physical Parameters > Phone Port > Calling Features section.

GenerateCPCSignal: "For inbound and outbound calls"    -->   "For outbound calls only"

Success!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
The phone rang, was answered, and we could talk!

OK, now I need to reset some of the parameters that I've been playing with back to their defaults....

I reset 3 of the 4 PSTN Disconnect detection parameters as follows,
DetectCPC: no
DetectPolarityReversal: yes
DetectFarEndLongSilence: yes
DetectDisconnectTone: yes

This broke things, and we were back to ringing followed by a dial tone again.

So I disabled the DetectPolarityReversal again as follows,
DetectCPC: no
DetectPolarityReversal: no
DetectFarEndLongSilence: yes
DetectDisconnectTone: yes

Successfully received a phone call again!

I reset the following 2 parameters to their defaults,
RingValidationTime: 256
RingIndicationDelayTime: 512

This again broke things, and we were back to ringing followed by a dial tone.

RingValidationTime: 100

no change, ring followed by dial tone

RingValidationTime: 256 (default)
RingIndicationDelayTime: 512  -->  256

Success again!!

Ran out of time to try resetting more parameters.  So at the moment, we have the following 5 settings altered on the OBi110:


                                         Default    -->     Now

Interfaces > Line

    Line Port
        Ring Delay:                      4000   -->     0

    PTSN Disconnect Detection
        DetectCPC:                      yes   -->     no
        DetectPolarityReversal:       yes   -->     no

    Ring Detection
        RingIndicationDelayTime:     512   -->     256


Interfaces > Phone

    GenerateCPCSignal:          IN & Out  -->  outbound calls only


-gary


Shale

Nice investigation and writeup. I looked up CPC, and found http://www.sandman.com/cpcbull.html to give a good description.

gary-gary

Quote from: Shale
Nice investigation and writeup. I looked up CPC, and found http://www.sandman.com/cpcbull.html to give a good description.

Yep, I found the same reference.  The interesting thing is that this article states:

"Battery Reversal hasn't been used in this country since they took out the last Step-by-Step CO switch."

Yet I found that if I did not disable 'DetectPolarityReversal', things would not work.  So I'm guessing that the PBX implements polarity reversal!

I had previously tried just disabling this setting by itself, with no success.

-gary

ianobi

Gary,

Congrats on your detailed investigation and just reward!


QuoteGenerateCPCSignal: "For inbound and outbound calls"    -->   "For outbound calls only"

I don't think I would ever have thought of that. I don't remember it being an issue ever before in any country.

Normally setting RingDelay to 0 means the OBi loses the ability to detect CallerID on incoming calls as this comes in after that first ring in North America. However, this PBX is so weird that maybe it sends it before the first ring - standard in UK and some other countries. This will be obvious by looking at Call History.

If the OBi110 works reliably and your parents choose to keep it, then you might want to consider better digitmaps etc for them. It should be possible to prepend "9 pause" to outgoing calls and allow for internal number ranges.

ProfTech

As noted by both QBZappy and the portal, Build 2824 has finally been released. Whatever bugs existed in 2774 and 2776 may have been corrected in the 2781M that you said yours contained, but you may want to consider loading 2824 anyway. I wonder if the M might have denoted some sort of beta bug fixed version, anyway.

gary-gary

Quote from: ProfTech
As noted by both QBZappy and the portal, Build 2824 has finally been released. Whatever bugs existed in 2774 and 2776 may have been corrected in the 2781M that you said yours contained, but you may want to consider loading 2824 anyway. I wonder if the M might have denoted some sort of beta bug fixed version, anyway.


Thanks for the tip... I've now updated both my and my parents OBi110 to the 2824 firmware.  I don't know what might have changed, but can't say that we've noticed any differences.

-gary

gary-gary

Quote from: ianobi

Congrats on your detailed investigation and just reward!

Well it appears that congratulations may be a bit premature... it works sometimes and sometimes it doesn't.  When it doesn't, it is back to the ring/dial-tone/ring again operation.  :-(

Quote
QuoteGenerateCPCSignal: "For inbound and outbound calls"    -->   "For outbound calls only"

I don't think I would ever have thought of that. I don't remember it being an issue ever before in any country.

It seems that this change has had an unexpected side effect.  One can no longer dial '#' to get to the pots line.  Instead the OBi gives a message to the effect that this service had not been configured.  :-(

Quote
Normally setting RingDelay to 0 means the OBi loses the ability to detect CallerID on incoming calls as this comes in after that first ring in North America. However, this PBX is so weird that maybe it sends it before the first ring - standard in UK and some other countries. This will be obvious by looking at Call History.


That was my understanding of RingDelay as well, but setting it to anything other than '0' results in no ring.


Yesterday my parents had a visit by a tech from the outside firm which manages the PBX (a Mitel 3300).  I was on the phone with him and viewing/changing OBi settings remotely as we tried to debug this.

He was not able to answer my questions regarding the PBX's implementation of CPC or polarity reversal, but said he'd look into them.

One item he noted was that when I called the pots line, the phone attached to the OBi did a strange ring.  Remember I'm calling from outside the PBX, so it generates a double-ring... but what he heard from the OBi's phone was more like a short ring and a half.  Shouldn't this be RingProfile A, DefaultRing 1 as configured under the Line Port settings?

So this brings up another question... must the incoming ring pattern match one of these listed in the associated ring profile (A in this case)... for the phone to ring?  And has setting ringdelay to '0' effectively disabled this?  Is the OBi somehow interpreting the incoming call as ring-hangup-ring-hangup?

I've been trying to locate some audio samples of Bellcore-dr1 etc for comparison, but have been unsuccessful so far.

-gary

ianobi

QuoteSo this brings up another question... must the incoming ring pattern match one of these listed in the associated ring profile (A in this case)... for the phone to ring?  And has setting ringdelay to '0' effectively disabled this?  Is the OBi somehow interpreting the incoming call as ring-hangup-ring-hangup?

There's quite a lot to unpick here. The incoming ring pattern has no connection with the Ring Profile. The OBi just needs to detect some sort of ringing. The RingDelay setting has no effect on detecting the incoming ring.

I think that you are correct that that the OBI is seeing ring-hangup-ring-hangup. The odd ring at the phone is probably due to the OBi hanging up before the phone has completed ringing. I think the "double ring" from the Mitel is this pattern:

(.4+.2,.4+2) - ring for .4s, silence for .2s. ring for .4s, silence for 2s.

The standard North American ringing (Mitel internal extensions?) is

(2+4) - ring for 2s, silence for 4s.

I'm not sure what any of that proves, except that I believe that the problem is still a question of ring detection. A ring is being detected but the following silence is being detected as a hangup. It may be worth trying to increase RingTimeout, which should make the OBi think that the ringing is lasting longer. Also, at least for now, disable all PSTN Disconnect Detection "Detect" settings.


QuoteOne can no longer dial '#' to get to the pots line.

This is very odd. Does the Phone Port OutboundCallRoute still have the following rule:

{(<#:>|911):li}


It would be helpful to have the actual spec for the Mitel 3300 analogue interface. I think we have a Mitel engineer somewhere on this forum. I will ask around.