Posted: Tue May 26, 2009 3:52 pm Post subject: [asterisk-users] Maximum cable length for analog phone from
Wilton Helm wrote:
Quote:
You are exactly right. Cat 5 had no advantage over cheaper wire for
voice, and the length limitations are meaningless. Consider that Cat 5
is typically use with signals that extent to 30 MHz or beyond. A voice
grade analog circuit must go to 4 KHz (1/10,000 as much). At 4 KHz,
the wire generally doesn’t even act like a controlled impedance.
I completely agree, but that said I still use cat5/e for everything
anyway, not worth having more than one kind of wire, and lets you change
your mind later on the usage. Once you are using outside plant
facilities though, you live with what you get, and don't expect much.
Quote:
Wilton
*From:* asterisk-users-bounces@lists.digium.com
[mailto:asterisk-users-bounces@lists.digium.com] *On Behalf Of *David
Gibbons
*Sent:* Tuesday, May 26, 2009 8:50 AM
*To:* Asterisk Users Mailing List - Non-Commercial Discussion
*Subject:* Re: [asterisk-users] Maximum cable length for analog phone
from FXS port
I could be wrong but I don’t think the cat5 limit of 100 meters
applies to any analog signaling over that copper. I believe it only
applies to Ethernet signaling.
Posted: Tue May 26, 2009 8:47 pm Post subject: [asterisk-users] Maximum cable length for analog phone from
If this is an emergency phone situation then I would question the wisdom
of even considering using Asterisk.
Conventional telephony solutions exist that will easily cover the loop
length and provide the reliability that should be required by risk
management in such a situation.
Appreciate all your input folks. Much of it very helpful in the greater
context of the initial question.
Thank you for the suggestion of using various wireless devices, but I'm
stuck with fixed wiring since this is a security/emergency phone(s)
installation underground in large tunnels.
Also, switching to VOIP is not really the answer here because then I'm
forced to solve a lot of power, repeaters/switches problems that arise. So
I'm actually worse of than using the analog connections I think.
I do have some control over the wiring/cable chosen for this project but
still forced to find a solution where I can feed the analog "phone line" the
total 3km line distance.
I would love to find a way to do this in the Asterisk context with some sort
of FXS feed, either from Digium (or compatible) hardware or any of the
available ATA boxes. The Sapura box suggestion may be something and I'll
look closer into that as well as continuing to look for other ways to do
this.
couple last words on this - if that is the application, then ringing the
remote terminal may not even be necessary, you really only care about
the hookswitch and audio which is a different thing entirely from ringing.
You may be able to boost the battery voltage with a simple dc adapter in
series to get the line build out capability you need. Just make sure its
floating with respect to ground and wire it in. Don't be afraid of
hurting the phone, you won't.
Check out dialplans for the ATA's for warmline and hotline for emergency
phones you will probably want this. This is one I use for example
warm dial - wait 3 sec and if not 3 digit number dial 100
( P3 <:100>|xxx )
ie: if they know who they want locally on the pbx they have 3 seconds to
dial it, otherwise the ata just dials extension 100 which is an
entrypoint to one of the IVR trees on my system.
Quote:
Appreciate all your input folks. Much of it very helpful in the greater
context of the initial question.
Thank you for the suggestion of using various wireless devices, but I'm
stuck with fixed wiring since this is a security/emergency phone(s)
installation underground in large tunnels.
Also, switching to VOIP is not really the answer here because then I'm
forced to solve a lot of power, repeaters/switches problems that arise. So
I'm actually worse of than using the analog connections I think.
I do have some control over the wiring/cable chosen for this project but
still forced to find a solution where I can feed the analog "phone line" the
total 3km line distance.
I would love to find a way to do this in the Asterisk context with some sort
of FXS feed, either from Digium (or compatible) hardware or any of the
available ATA boxes. The Sapura box suggestion may be something and I'll
look closer into that as well as continuing to look for other ways to do
this.
Posted: Tue May 26, 2009 9:06 pm Post subject: [asterisk-users] Maximum cable length for analog phone from
John Novack wrote:
Quote:
If this is an emergency phone situation then I would question the wisdom
of even considering using Asterisk.
Conventional telephony solutions exist that will easily cover the loop
length and provide the reliability that should be required by risk
management in such a situation.
why are you going on the assumption asterisk is somehow inherently less
reliable than a "conventional" solution ?
I am not trying to start any sort of war here, but is that based on any
sort of facts ? hardware wise its basically all the same electronics
whether they were meant as a general purpose computer or a telephony
specific computer - they all fail eventually and the MTBF is usually
related to the relative price in the specific market. I have not really
had any software reliability problems in years of running asterisk
(although some do and I am sure there are firmware revs for pbx's that
have issues too)
so why make that general statement ?
as far as risk management - any one system can fail, end of story. Risk
management would entail a backup system if failure of the primary is not
acceptable. In a tunnel application physical damage to the wiring is
probably a lot more likely than a hardware failure, be it from accident,
fire, collapse etc., meaning when you need the phone most, it is least
likely to work. Those factors would affect any hardwired telephony
solution equally.
> Appreciate all your input folks. Much of it very helpful in the greater
> context of the initial question.
>
> Thank you for the suggestion of using various wireless devices, but I'm
> stuck with fixed wiring since this is a security/emergency phone(s)
> installation underground in large tunnels.
>
> Also, switching to VOIP is not really the answer here because then I'm
> forced to solve a lot of power, repeaters/switches problems that arise. So
> I'm actually worse of than using the analog connections I think.
>
> I do have some control over the wiring/cable chosen for this project but
> still forced to find a solution where I can feed the analog "phone line" the
> total 3km line distance.
>
> I would love to find a way to do this in the Asterisk context with some sort
> of FXS feed, either from Digium (or compatible) hardware or any of the
> available ATA boxes. The Sapura box suggestion may be something and I'll
> look closer into that as well as continuing to look for other ways to do
> this.
>
> tnx!
>
> Baldvin
>
>
>
>> -----Original Message-----
>> From: asterisk-users-bounces@lists.digium.com [mailto:asterisk-users-
>> bounces@lists.digium.com] On Behalf Of Hans Witvliet
>> Sent: 26. maí 2009 19:42
>> To: novackster@gmail.com; Asterisk Users Mailing List - Non-Commercial
>> Discussion
>> Subject: Re: [asterisk-users] Maximum cable length for analog phone
>> from FXS port
>>
>> I would suggest making a wifi connection with directional hi-gain
>> antenna's.
>> Ans a small box at the other end. Have a look at:
>> http://www.fit-pc.net/fitpc-2-p-2.html or http://www.fit-
>> pc.info/downloads/handleidingen/fit_pc_2_eng.pdf
>>
>> _______________________________________________
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>> asterisk-users mailing list
>> To UNSUBSCRIBE or update options visit:
>> http://lists.digium.com/mailman/listinfo/asterisk-users
>>
>>
>
>
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>
>
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Appreciate all your input folks. Much of it very helpful in the greater
context of the initial question.
Thank you for the suggestion of using various wireless devices, but I'm
stuck with fixed wiring since this is a security/emergency phone(s)
installation underground in large tunnels.
Also, switching to VOIP is not really the answer here because then I'm
forced to solve a lot of power, repeaters/switches problems that arise. So
I'm actually worse of than using the analog connections I think.
I do have some control over the wiring/cable chosen for this project but
still forced to find a solution where I can feed the analog "phone line" the
total 3km line distance.
I would love to find a way to do this in the Asterisk context with some sort
of FXS feed, either from Digium (or compatible) hardware or any of the
available ATA boxes. The Sapura box suggestion may be something and I'll
look closer into that as well as continuing to look for other ways to do
this.
Ah! that explains.
As ordinary ethernet and wifi are impossible, and lines are too long for
ordinary analoge phones, options are limited.
Another idea is to use baseband modems, just like the pair used by
telco's for DSL. You can bridge 5KM or more...
If it's for a small number of phones, T1/E1 modems might be
impractible/expensive. And i presume you don't have a DSLAM lying around
there ;-)
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Posted: Tue May 26, 2009 11:20 pm Post subject: [asterisk-users] Maximum cable length for analog phone from
Even with 'conventional' PBXs, there is such a thing as power fail devices where the extension is cut to a telco pots line for dial tone if the PBX goes down.
Jon Pounder wrote:
Quote:
Quote:
John Novack wrote:
Quote:
If this is an emergency phone situation then I would question the wisdom
of even considering using Asterisk.
Conventional telephony solutions exist that will easily cover the loop
length and provide the reliability that should be required by risk
management in such a situation.
why are you going on the assumption asterisk is somehow inherently less
reliable than a "conventional" solution ?
I am not trying to start any sort of war here, but is that based on any
sort of facts ? hardware wise its basically all the same electronics
whether they were meant as a general purpose computer or a telephony
specific computer - they all fail eventually and the MTBF is usually
related to the relative price in the specific market. I have not really
had any software reliability problems in years of running asterisk
(although some do and I am sure there are firmware revs for pbx's that
have issues too)
so why make that general statement ?
as far as risk management - any one system can fail, end of story. Risk
management would entail a backup system if failure of the primary is not
acceptable. In a tunnel application physical damage to the wiring is
probably a lot more likely than a hardware failure, be it from accident,
fire, collapse etc., meaning when you need the phone most, it is least
likely to work. Those factors would affect any hardwired telephony
solution equally.
Appreciate all your input folks. Much of it very helpful in the greater
context of the initial question.
Thank you for the suggestion of using various wireless devices, but I'm
stuck with fixed wiring since this is a security/emergency phone(s)
installation underground in large tunnels.
Also, switching to VOIP is not really the answer here because then I'm
forced to solve a lot of power, repeaters/switches problems that arise. So
I'm actually worse of than using the analog connections I think.
I do have some control over the wiring/cable chosen for this project but
still forced to find a solution where I can feed the analog "phone line" the
total 3km line distance.
I would love to find a way to do this in the Asterisk context with some sort
of FXS feed, either from Digium (or compatible) hardware or any of the
available ATA boxes. The Sapura box suggestion may be something and I'll
look closer into that as well as continuing to look for other ways to do
this.
I would suggest making a wifi connection with directional hi-gain
antenna's.
Ans a small box at the other end. Have a look at:
http://www.fit-pc.net/fitpc-2-p-2.html or http://www.fit-
pc.info/downloads/handleidingen/fit_pc_2_eng.pdf
_______________________________________________
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Posted: Tue May 26, 2009 11:56 pm Post subject: [asterisk-users] Maximum cable length for analog phone from
Jon Pounder wrote:
Quote:
John Novack wrote:
> If this is an emergency phone situation then I would question the
> wisdom of even considering using Asterisk.
> Conventional telephony solutions exist that will easily cover the
> loop length and provide the reliability that should be required by
> risk management in such a situation.
>
why are you going on the assumption asterisk is somehow inherently
less reliable than a "conventional" solution ?
Because it is.
A simple solution is best.
fewer items to fail.
The OP has given no reason to develop a complex solution for what is
presented as a fairly simple problem to provide communications in an
emergency situation over a short loop in conventional telephony
3Km isn't a long loop in the telephone world, though some postings would
incorrectly say otherwise.
Quote:
I am not trying to start any sort of war here, but is that based on
any sort of facts ? hardware wise its basically all the same
electronics whether they were meant as a general purpose computer or a
telephony specific computer - they all fail eventually and the MTBF is
usually related to the relative price in the specific market.
Why do you assume a "telephony specific computer" is even needed?
KISS!
John Novack
--
Dog is my co-pilot
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Posted: Wed May 27, 2009 2:28 am Post subject: [asterisk-users] Maximum cable length for analog phone from
[snip]
Quote:
You may be able to boost the battery voltage with a simple dc adapter in
series to get the line build out capability you need. Just make sure its
floating with respect to ground and wire it in. Don't be afraid of
hurting the phone, you won't.
But it is possible to hurt the ATA if it causes more current than expected
to flow. It is even possible to force reverse voltage into the ATA that
way. A line fault would make it even more likely.
Wilton
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