[Asterisk-Users] Channel bank replacement

[Peter Hoppe]

Thank you so much for your answers already, I really appreciate it!

I have looked into using an Adtran Total Access 750 platform instead, 
but got away from that idea after I saw the totally confusing amount of 
options of different modules I can buy. The Adit 600 seemed so much 
simpler to put together. Also, the Adit 600 had such an excellent 
appraisal in the asterisk voip-info - see

http://www.voip-info.org/tiki-index.php?page=Asterisk%20Channel%20Bank

But maybe I need to come back to the Adtran TA750. Unfortunately that 
platform seems to only offer 24 fxs ports per unit and I need to buy an 
expensive T1 card. I would buy the Digium T1 card - it seems that it is 
by far the least expensive card, but $500 is still something. That's why 
I toyed with the Adit 600 plus cmg card - all I need is a standard 
network card on the Asterisk machine.

We have sorely abandoned the idea of using an extensive amount of voip 
phones on the property, as we are not a homogenous office setup (ppl 
also live on the property).
This solution would mean
* putting in an entire new cat5 network. I would be the person who would 
have to put it all in place - When would I be finished? In 2 years? 4 
years? 10 years?
* lots of admin hassle to enable all the phones / add new phones / 
remove phones
* users can't easily extend stations at end points. With two wire phone 
they simply switch one parallel to the existing one - no admin hassle / 
extra hubs etc.
* two wire technology enables us to buy almost any phone available.
* security concerns with the SIP protocol. See 
http://secunia.com/advisories/8169/ as an example
* users potentially plugging their laptops into the voip sockets and 
browsing/downloading away => lots of setup/admin hassle with the 
firewall (how do you block Kazaa?)
* Phones potentially breaking when users unplug power during firmware 
download. For example, this is an issue with the Grandstream phone.

The only alternative that seems feasible at the moment would be

* a different channel bank than the adit 600 or

* a voip gateway that multiplexes many fxs ports into one ethernet 
connection. But before I would go down that route I would have to be 
absolutely sure that the SIP conforms to the standard, the upgrades are 
free and the fxs ports are compatible with uk standard two wire phones. 
I found that some two wire phones actually use 4 wires - confusing

* a bank of ATAs (handytone 286 or similar). I *really* don't like that 
solution, as it is a bad botch job and throws lots of issues like which 
REN they have, many power supplies (or one big one). I really ought to 
be red in the face for even mentioning that solution. But if nothing 
else is available, I would probably have to buy them in bulk, take the 
boards out and mount them in a 19'' box together with a hub so I build 
my own voip gateway :) maybe it's not so botch after all :) )


For connection to the PSTN: We have three BT lines, and again, we would 
not like to move over to a different technology like ISDN. The lines 
work for us, and 'if it ain't broke, don't fix it'. We would use three 
Sipura SPA-3000 interfaces to connect them to the internal network. The 
SPA-3000 is sold in the UK and has the CE approval, so it should legally 
be ok. I am experimenting with one unit at the moment, and am smacked by 
the literally hundreds of options it has. But I heard good reports about 
that one, so I expect it to work well in our setting.


> Hi Peter, I'm not sure how you are getting PSTN lines into your * box, but if 
> it's not ISDN30, you might want to consider some of the cheap IAX phones on 
> the market now rather than trying to soldier on with old analogue kit?
> 
> e.g. http://www.iaxtalk.com/product_info.php?cPath=1&products_id=29
> 
> Shipping for 30 units and UK power supplies was $340, and with the weak dollar 
> right now, that works out at just over 40 quid per phone - I'm sure there's 
> movement on the unit price when buying in bulk...
> 
> Now remove the need for an Asterisk Quad-E1 / T1 interface card and you've 
> dropped the cost by nearly a grand.... food for thought :)
> 
> They also sell a single-ethernet-port version of the phone for $10 less if you 
> have enough ethernet sockets.
> 
> Cheers,
> Gavin.




> I got an Adtran 600 with 12 X FXO and 12 X FXS cards for $495 from Penny
> Doyen [pdoyen at mnitx.com]. With the strength of the pound, that would
> practically be free to you!
> 
>  
> 
> Chris Mason




> Date: Fri,  8 Apr 2005 17:42:56 +0200
 >
> Maybe following options:
> 
> 1-) Get another channel bank from ebay at low cost. Which will also need another
> T1 card;
> 
> 2-) Use 40 voip phones at 50 USD each and you no longer need the card neither
> the channel bank. But a reliable local network ;


>> Hello,
>> 
>> I am working for a charity in the UK and I am projecting a new phone system.
>> 
>> We would like to connect our two-wire telephones (40 or so) to an ADIT 600 channel bank, and connect that into an Asterisk box via the CMG card or T1 card.
>> 
>> I have been in talks with Carrier Access about the purchase of a new channel bank and we tried to get a minor version of it first for testing with the intention of upgrading to the full product if we are happy with it.
>> 
>> Unfortunately since a few months I cannot get any further with CAC, as they keep not coming back to us on how we proceed. I feel that the channel bank would be the best solution, but it seems that we are just to small fish to fry for them.
>> 
>> So - would there be any other way to connect 40+ telephones (two wire) into an asterisk box? Are there any voip gateways that actually conform to SIP standard (unlike what I heard from the Mediatrix voip gateways 1124 and 1204 which seem to use non standard SIP and have pay-as-you-upgrade)?
>> 
>> Thank you very much for your consideration!
>> 
>> Peter Hoppe
>