[Asterisk-Users] Port density: DS3 cards?

[William Waites]

On Thu, Dec 04, 2003 at 04:58:03PM -0600, Steven Critchfield wrote:
> > 
> > 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.

Oh, granted. I would only do this on a reasonably high end PC
with a good chipset.

> 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.  

I wouldn't suggest doing that! I would do something like:

                                  | cluster of asterisks
OC3/DS3 <---> * <---> TDMoE <---> | for recording, vm,
                                  | voip gateway, etc.

and keep the config on the DS3-TDMoE box as simple as
possible.

ideally the DS3 interface is plugged into a 64bit 66MHz bus as well.

btw, jason thorpe at nasa has benchmarked gige cards on netbsd/i386
doing well in excess of 500Mbps so it /is/ possible.

-w

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