[Gllug] dual voip + landline phone for linux

[Andy Farnsworth]

Ben Fitzgerald wrote:

>On Sun, Oct 23, 2005 at 12:42:25PM +0100, Martin N Stevens wrote:
>  
>
>>>I don't want to go beyond £100 (I'm from oop north!).
>>>
>>>Dual function (analog and VOIP) appeals as I have broadband through BT
>>>and the fallback to analog appeals (my girlfriend will have my scalp if
>>>the phone is unreliable!!!). My connection is 512down 256up. I'm
>>>considering upgrading this as recently I've needed more bandwidth.
>>>
>>>Suggestions for cheap, non-lock in VOIP -> POTS providers would also be good.
>>>Pay as you go preferred.
>>>      
>>>
>>I would do this with something like asterisk at home, with a Grandstream
>>VOIP phone, and a POTS card.
>>    
>>
>
>Okay, I've done some reading and priced this. I now see my £100 estimate
>was, well, optimistic. I'm hoping some gllugers can bring the price down
>with advice, but if not, well, I'll have to pay up! :-X
>
>Here is what I'd like to use:
>
>               adsl
>                 |
>           router/firewall
>                 |
>                 |
>        /----------------\
>       |                  |
>     VOIP               POTS_____    PC
>     phone              card      asterisk
>
>For the VOIP phone the grandstream looks cheap + cheerful. Yes snom is
>nice but overkill for home use. I can get a budgetone 102 for £50 on
>ebay.
>
>For the POTS card digium seems the linux default. I was thinging TDM01B
>(1 FXO, 0 FXS) for £85.
>
>The rest (except for my time spent learning asterisk + configuring my
>firewall) is free.
>
>PC is running debian, PIII 700MHz, BTW.
>
>My understanding is:
>
>I plug the VOIP phone into the LAN. I configure it to use asterisk
>running on a PC on my LAN as it's pbx.
>
>Outgoing: Asterisk routes the call as appropriate (voipfone/voipcheap/etc).
>Incoming: Asterisk handles the call on FXO port, consults rules and routes
>to VOIP phone if appropriate.
>
>Questions I would like to check before I pay out:
>
>* is the above setup technically correct? If I have anything wrong I'd
>+really+ appreciate a heads-up.
>
>* are there any rebadged digium cards out there of similar quality for less?
>
>* Is this config the best to have (assuming I want my own pbx - yes,
>overkill, but I want to learn this).
>
>  
>
Ben,

Mainly correct, your  POTS card should be swapped with your PC-Asterisk 
to be correct as the network goes through the PC before getting to the 
pots card.
You can get a cheap pots card which is really a voice modem for about 
£15 however the quality of the voice across it is abysmal, fine for 
testing and developing, but you DON'T want to use it live.  Another 
option (more expensive) is to get the Digium card with 1FXO and 3 FXS 
ports giving you the ability to have 3 normal pots phones and one land 
line.  The digium cards have Excelent sound quality.  Then the other 
option is to use an ATA device (analog telephone adapter) such as the 
SPA-3000 which I have shown configured below.

               adsl
                 |
           router/firewall
                 |
                 |
          /---------------\
          |               |
      SPA-3000            PC
          |             asterisk
          |
    /--------------\   
    |              |
  FXO port       FXS Port
   PSTN Line       Normal POTS Phone


SPA-3000 costs £80 or less
normal POTS phone £5-10
Soft VOIP phone Free (see iaxphone or others)


Then add VOIP phones as you go along.

Andy Farnsworth

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