Low cost 8 port BRI interfaces


#1

Hi, I am planning a pbx with a possibly unusual set-up these days. There’ll be at least 4 BRI lines in T mode (outgoing to the PSTN in point-to-point mode (Anlagenanschluß for Germans)), 12 BRI lines in NT mode (connected to phones in point-to-multypoint setup (Mehrgeräteanschluß for Germans)), three FXS ports to connect analogue phones and last but not least a VOIP connection for occasional use.
Sicne the number of PCI slots are limeted in a PC I’ll need two 8-port BRI cards and a FXS adapter supporting at least 3 lines.

I can find numerous low cost single S0 (BRI) adaptors with the HFC chipset that can run in NT mode. They cost about 24 EUROs. However so far I have only seen 8-port cards in the 700 EURO plus range.

I noted that these modules often contain echo cancelation hardware - is this really needed for the above setup?
I will use a modern PC i.e. 1024 MB RAM and an Athlon 3000 CPU.

Thanks for any help and hints
Roland


#2

Hi

Do you mean port or channel? as if you are meaning port ie 16 channel then you should be looking at PRI, Rule of thumb is 8 channels and above it is far more cost effective to use PRI as a cards are far cheaper channel for channel

Ian


#3

[quote=“ianplain”]Hi

Do you mean port or channel? as if you are meaning port ie 16 channel then you should be looking at PRI, Rule of thumb is 8 channels and above it is far more cost effective to use PRI as a cards are far cheaper channel for channel

Ian[/quote]

Well, currently we’ve subscribed to 4 external s0 lines giving us 8 B-channels.
Internally ther’s those 12 S0-Buses with two channels each, i.e. 24 B-Channels total.
Each of these 12 buses is wired to a different room location.
/Ro


#4

Hi

Ok , Im sorry to say but for what you are trying to do you would be far better of using a ISDN switch. You are trying to do tdm switching and with this number you will need to use cards with an mvip bus or the like. and 700 euros for an 8 port(16 channel) card is cheap, and I doubt it would be compatible with Asterisk. Have a look at beronet or AVM for compatible cards. It may be worth bouncing your idea of the guys at beronet to see what they think.
You could also look at vegastreams isdn to sip gateways.

Ian