[Asterisk-Users] Quad T1 Card

[Kevin P. Fleming]

----- Michael Collins <mcollins at fcnetwork.com> wrote:

> Kudos to Digium on this one!  Keep us posted on the progress - I
> think
> this will be a quantum leap forward for the open-source telephony
> community.

I think you are overstating the idea here. While the echo canceller is technically a 'DSP', it is not a _programmable_ DSP like you find on the $10K boards. These parts will never be able to do speech detection, call progress analysis, codec transcoding, etc., and they are not intended to. Using the term 'DSP' for these parts seems a bit disingenuous to me, since it implies in the reader's mind a great deal more capability than they actually have.

The whole concept of 'put the complex burden on the host CPU' is still valid here; the reason that the echo cancellation is being moved to the cards is one of quality (host CPU-based cancelers are not yet as good as the available hardware choices) and 'closeness' to the TDM interface (which also can impact quality). The other functions that can be done by the DSPs on boards like the Aculab Prosody X don't actually benefit from being 'on the card'; they can be done equivalently on the host CPU (except for capacity differences, of course). It's up to the customer to decide which way they want to spend their money.

-- 
Kevin P. Fleming
Senior Software Engineer
Digium, Inc.