asterisk users - Nov 2004 - [Fwd: Re: Adit 600 channel bank in UK setting]

Peter
- 40 phones and only 3 PSTN trunks?.  I would recommend at least 2 BRIs
for this.  If you have ISDN you can also get DDI to the extensions.I
would strongly recommend abandoning the analogue PSTN lines and using
ISDN.  The setup pain you will go through will be significantly less,
combined with better audio, more features (like DDI numbers!) and much
more robust connections.

You should look at an HFC based ISDN BRI card which you can get for
around ?11 if you shop around here in the UK. I have 3 of these cards
running in an Athlon 400, one of which is connected to a standard BT
ISDN line.  The rental for an ISDN line here in the UK is a shade more
than for 2 business analogue lines.  If you add in the cost of caller
id, etc. it actually works out cheaper.

You will need the 'bristuffed' version of Asterisk which you download
from www.junghanns.net/asterisk/downloads

You could use a channel bank for the analogue POTS interfaces, but watch
for the gotchas

- line impedance is diffrent to the US (lots of sidetone and echo on UK
phones)
- caller display may not work unless the channel bank supports the BT or
UK cable/ETSI caller id specs.
- EMC/electrical safety - specs you state do not appear to be EU accepted.
- you will pay import duty and VAT and customs clearance if you bring it
into the EU
- no spares here.
- You will still need a Digium E1 or T1 card for $500 plus taxes as above.

Channel banks are a peculiar US thing. Be careful!  You will almost
certainly be better off using voip handsets (SNOMs are cool, avoid
Grandstream for anything other than domestic environment) and a few
Sipura-type ATA's for the analogue fax machines etc. or some Digium
analogue cards.

A more detailed use case would be helpful if you want more advice on
your specific project.  Email me off line if you want details of my config.

Do the maths first!  Hope this helps.

Best regards
Tim Robinson
Basingstoke, UK


Peter Hoppe wrote:
> Hello!
> 
> I am projecting a replacement telephone system for a small organization 
> in the UK. Our old pbx is showing signs of age and will probably soon go 
> into pension.
> 
> 
> 
> At present the plans are:
> 
> * The IP phones are connected to a switch and the switch is connected to 
> the asterisk box via a network card. The asterisk box would be a 
> standard PC with Asterisk running on SuSE Linux 9.0.
> 
> * The 2wire phones are connected to a channel bank and the channel bank 
> has got a T1 port which is connected to the asterisk box via a T1 card.
> 
> My question concerns the channel bank. We would like to use a Carrier 
> Access ADIT 600 with
> 
> * 1 dual T1 controller card
> * 1 230 VAC/-48 VDC Power supply/charger card
> * 5 fxs 8 channel voice service cards (which allows us to connect up to 
> 40 telephones)
> * 1 fxo/dpt 8-channel voice service card (to connect the three BT lines; 
> a bit of a waste, but I couldn't find an fxo card with less fxo ports).
> 
> 
> To connect the channel bank to the asterisk box we would equip that box 
> with a Digium Wildcard T100P card and use a cable terminated with RJ48 
> plugs on both ends.
> 
> My questions are:
> 
> * Is it legal in the UK to connect an Adit 600 channel bank (with the 
> fxo card) to a BT line (PSTN)? In the technical specification sheet that 
> I downloaded from the carrier access website there is mention of 
> different regulatory approvals:
> 
> - FCC Part 68, CS-03 (not registered for connection to the PSTN)
> - FCC Part 15, ICES-003 Class A
> - NRTL safety listed: UL 1950, CSA C22.2 No. 950
> - NEBS Level-3 certified as type 2 and 4 equipment (Intrabuilding)
> - TelcordiaTM GR-63-CORE, GR-1089-CORE
> 
> If not, does anyone know of another legal way to bring three BT lines to 
> an asterisk box?
> 
> 
> * Has anyone noticed problems connecting UK PSTN lines to the channel 
> bank with the aforementioned fxo card?  Would dialling work 
> satisfactorily? What about ringing when outside calls come in? What 
> about the audio quality? Would prolonged conversations be sustainable?
> 
> 
> * Has anyone noticed problems connecting standard 2wire phones to the 
> channel bank with the aforementioned fxs cards? With standard 2wire 
> phones I mean phones that one can buy in any shop. We had some question 
> marks over this issue because of the problems with the handytone adaptor 
> - but my personal opinion is that there is a world of difference between 
> the channel bank and the ht adaptor; however, we need to be sure of that.
> 
> 
> * Is it conform to the UK standard to use a T1 connection between 
> asterisk and the adit 600, or should we rather use an E1 connection? We 
> want to avoid locking ourself into having to buy spare parts from the US 
> in case the T1 connection breaks down. Can we get T1 cards in the UK or 
> would people rather recommend E1? The Adit 600 can also be equipped with 
> a controller that has 2 E1 ports.
> 
> 
> Thank you very much for your considerations!
> 
> 
>

On Thursday 18 November 2004 22:16, Tim Robinson wrote:
>
> Channel banks are a peculiar US thing. Be careful!  You will almost
> certainly be better off using voip handsets (SNOMs are cool, avoid
> Grandstream for anything other than domestic environment) and a few
> Sipura-type ATA's for the analogue fax machines etc. or some Digium
> analogue cards.
So what would you advise using in the UK to interface with standard 2 wire 
phones - I'm trying to avoid having to use ata type adapters.

Jon