Re: Comcast Telephone Service!!! The saga continues!!

["ABLE_1" <royboynospam@xxxxxxxxxxxxx>]

Re: Comcast Telephone Service!!!  The saga continues!!

Well I now have some more info to throw into the mix on this Digital Phone
issue with Comcast that I will share.  My hope is that it will help others
as well.

It has been about 2 weeks since my last post on this subject.  Since that
time the customer has had continued daily problems with his phones as well
as his high speed internet connection.  He was ready to pull the plug on
Comcast when they determined that there was a problem with an 'amplifier' in
his area as well as a 'bad cable' underground and some connectors that was
affecting some three other customers in his area.

Three days ago the equipment was changed and the cable replaced and all has
been well since.  Today I performed another test of the system to Central
Station and OK.  Did a DL and all OK.

The customer made the comment that most people at Comcast seem incompetent
except for one the has made the above repairs and suggested that I call him
since I did have some more questions.

I contacted the tech and he explained as above what he knew about the
issues.  I asked if he could tell me what the line voltages were so that I
may re-activate the line monitor so as to be a little more comfortable with
this Digital Voice technology.  He indicated that he was not sure what the
voltages were but would get one of his tech's on the line.

The tech said that (reading from the book) the following were the voltages.

    ON Hook Voltage     24 - 48vdc
    OFF Hook Voltage      6 - 12vdc
    Ring Voltage               60 - 90vac

I explained about a concern with the ON Hook voltage potentially be as Low
as 24vdc since the line monitor may see that as a problem on the line.  He
asked if I can adjust the threshold of the line monitor and I explained not
any more possible than him boosting the output voltage of the modem.

I then asked if they had wired the panel properly for line seizure thru the
RJ31X and he said that he did not know exactly.  I put enough doubt in his
head that he wanted me to talk to the 'Comcast Tech Trainer' that would know
more about the details of what I was asking.

I had to explain that I will discuss with their Trainer but did not want to
get into a long consultation in teaching Comcast how to connect an alarm
panel for line seizure.
He indicated that they have been installing this equipment from Philadelphia
to Harrisburg for quite some time and didn't seem to have any problems with
other alarms.  I explained that maybe "others" were not looking as hard.

I am presently waiting for a phone call from the Trainer and will post the
results of that conversation.  Maybe Monday till I get a call back.

I already have an appointment next week to visit the site for a small
upgrade and at that time will look at how they have put this together.

More to follow, and maybe pictures.

Les





> Ok, more info.  At some point last night after the successful test the
> customer no long had phone service.  Can you say crashed???
>
> Today Comcast came out and determined that the modem (Motorola) was
> defective and they replaced it with a Arris Model# TM402P\110.  And the
> phone is working again.  Sent signals to Central Station and all OK.
> Tried to Download to my office PC and again all OK.
>
> I Googled the model number and the .pdf spec sheet indicated that it uses
> Codec G.711.  So based on the info below this is good.
>
> I asked my customer to do some regular test for the next few weeks.
>
> He agreed.  More info later.
>
> Later,
>
> Les
>
>
>
>> It seems that transmitting touch-tones is a known problem with some VOIP
>> systems, and it has to do with the "codec" being used.  The codec is the
>> equipment or program that converts digital data into voice, and vice
>> versa.
>> Codecs based on the G.711 standard transmit touch-tones seamlessly, but
>> they generate a 64kbps output.  Other codecs, such as the G.729, compress
>> things down to an 8kbps data stream, which apparently raises hell with
>> touch-tones.  Even when using a "full rate" codec such as the G.711, it
>> helps if "echo cancellation" and "silence suppression" are turned off,
>> but
>> I have no idea who does that, or how.  The 8kbps codecs presumably cost
>> less and allow more calls to fit within the same bandwidth.
>>
>> So, the key to determining whether an alarm system will work on a VOIP
>> system may be to determine the type of codec that is used by the VOIP
>> interface.  Assuming the cable companies won't tell or don't know,
>> googling
>> the part number might produce some useful information.
>>
>> - badenov
>>
>
>