[asterisk-users] Question about DSP in Digium card

[Steve Totaro]

A. Levy wrote:
> Hello.
> I have a TE405P Digium Card (4 E1's) with ISDN protocol and I need to 
> find out if there is any limitation about DSP capabilities, I mean, I 
> am not sure how many phone calls my Digium card supports, 
> simultaneously. The calling flow goes from IAX <-> ISDN.
> I am running this card into CPU like this:
> - Micro PIV 3.0
> - 1Gbyte Memory
> Thanks.
> Levy.-

120 simultaneous calls.  AFAIK the DSP functionality is mostly offloaded 
to the the server's CPU so the server is going to be your bottleneck, 
not the card.  Your system should be OK I think.  I ran 95 simultaneous 
call through HP DL320's with 3ghz P4 and a gig of RAM and straight 
ULAW.  Top showed 50%-60% utilization with all 95 channels in use.  
These boxes only served as gateways between TDM and SIP and passed the 
calls to another Asterisk server that handled all of the other 
functionality (queues, meetme, etc)

Just my personal experience, but I do not find IAX to be very reliable.  
Is there any particular reason you are not using SIP?

Thanks,
Steve Totaro
www.asteriskhelpdesk.com