[asterisk-users] GSM SIM Cards and Digium, or GSM SIM Adaptor

[Tzafrir Cohen]

On Mon, Jan 14, 2008 at 01:25:13PM -0000, Chris Bagnall wrote:
> > Or I have to use an FXS to SIM adaptor? If yes, then
> > anyone advise a models and prices?
> 
> I'll leave others to suggest models and prices, but in my experience, 
> you're better with a SIP->GSM gateway and cutting out the analogue 
> loop altogether. They're a bit more expensive, but it'll save you 
> many hours playing with echo cancellation and gain settings on the 
> FXS module.

You don't have to have analogue loop. There are a number of GSM PCI
adapters, and all of them seem to have a separate signalling channel
between the GSM device and Asterisk.

For instance, the GSM support included in bristuff (used for the
Junghanns GSM adapter) sets each GSM port as an ISDN-like device with 
just one B channel but still with one D channel.

AFAIK, both the Bero.net and the VoiSmart GSM devices are likewise
digital.

-- 
               Tzafrir Cohen
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