[Asterisk-Users] Port density: DS3 cards?

[Steven Critchfield]

On Thu, 2003-12-04 at 16:52, William Waites wrote:
> On Thu, Dec 04, 2003 at 10:34:02PM -0000, Linus Surguy wrote:
> > I don't want to criticize your idea, but you do have to consider certain
> > points. Starting from (as has already been mentioned) the bandwidth of DS3
> > is far too much to reasonably shove down the PCI bus without data loss /
> > excessive overheads.
> 
> ??? 
> 
> a standard 32 bit 33MHz PCI bus has a maximum bandwidth of
> 133MBps == 1Gbps. a DS3 is 45Mbps. even if you pass the data
> over the bus 10 times, you're still only using up half the
> peak bandwidth.

Thats only if you could get full theoretical speeds. I have friends who
work on ranked supercomputers that will tell you how far short most
chipsets fall of the theoretical. Also remember the DS3 speed you
mention is a one way speed. Voice being bidirectional means that it
would pass the PCI bus in and some going out. Then if you plan on doing
any recording, there will be another crossing of the PCI bus to either
go out the ethernet cable to a drive subsystem that could handle the
speed, or to a decent SCSI system locally.  
-- 
Steven Critchfield  <critch at basesys.com>