[Asterisk-Users] DS3000P - 20 E1 capacity on single card

[Kevin P. Fleming]

Andrew Kohlsmith wrote:

> Yes, but then what are you doing with it?  You're shuttling the new data 
> to/from a network card in a lot of cases.  Combined with other traffic over 
> the PCI bus for normal system operation I could see you coming close to the 
> limitations of regular ole PCI.

Absolutely. The DS3000P will definitely support PCI-X, and probably bus 
speeds of 100MHz or higher, so at least if your system has that you will 
have plenty of bus capacity. Many servers nowadays actually have their 
NICs on a separate PCI bus as well, so the TDM and NIC cards won't be 
contending for the same resources.

> True enough, but you still need to marshall the data going between PCI busses 
> and to system memory.  Certainly not impossible problems to overcome but they 
> do add to the fun of getting a low latency VOIP system together.

Very true; realistically, modern PC hardware has more than enough 
bandwidth to do what is required. The real issue is timing, based on 
contention for resources, and how that impacts latency. The existing 
boxes out there (not PCs) that handle DS3 have far lower performance 
metrics than a 3GHz P4 or similar system :-)