[Asterisk-Users] Pros and Cons of T1/E1 cards

[Kevin P. Fleming]

David Waugh wrote:

> This means for example that the card could be used for a conferencing application with 24 users with echo cancellation/ gain control being handled by the card - and not having to be processed by the central CPU.

That is correct, of course, but keep in mind that having enough CPU 
horsepower to do those functions on the host will cost less than $1000US 
more than a system that couldn't (and that's assuming your low end under 
$1000US box cannot do it... many of them can).

This is the reason why even Intel/Dialog has moved towards 'host media 
processing' instead of DSP-laden boards... the DSPs are just more 
expensive per unit than doing the same work on the host CPU. Dedicated 
ASICs (like echo cancellers and conferencing engines) appear to still 
have a market, but using general purpose DSPs for these functions is no 
longer cost-effective.