[asterisk-users] FAX Issues

[Steve Totaro]

On Tue, Aug 9, 2011 at 8:13 PM, Steve Totaro
<stotaro at asteriskhelpdesk.com> wrote:
> On Tue, Aug 9, 2011 at 6:15 PM, Ryan McGuire <rdmcguire01 at gmail.com> wrote:
>> Unless your network is under load and you are seeing dropped packets
>> and high jitter, I would absolutely not do T.38. The cheapest and
>> easiest approach that I have found is to buy yourself an FXS gateway
>> and just make sure you are using ulaw.
>
> SLIN and Alaw work just fine.  Again, where are we referring to, the
> SIP provider or the LAN, something you can control or not?
>
> If faxing is not important then any solution is fine.
>
>>
>> Is this for personal use, or for business use? One feature that you
>> may want to utilize is fax tone detection if you only have a single
>> incoming line. If you use fax tone detection you can send the call
>> directly to your FXS gateway.
>
> Asterisk has this built in.
>
>>
>> I've successfully faxed through my SIP provider as well as through an
>> FXO gateway going to a DOCSIS modem (consumer grade "digital voice").
>
> Do you mean a cable modem?  They love to use "Digital Voice" when it
> is just VoIP.
>
>> TDM and POTS are really synonymous by the way, TDM is just a more
>> specific acronym (time-division multiplexing).
>
> POTS is not use TDM.
>
> A T1 would use TDM to MUX 23(4) calls onto a two pair.  POTS is a
> single pair and comes off some sort of TDM mux device somewhere.
>

That came out wrong, POTS and TDM are not synonymous.  TDM allows
multiple simultaneious calls over the same copper.  You can get call
waiting on POTS but that is about it.