[asterisk-users] Asterisk "Clusters"

[Mitch Thompson]

Hello, All.

I've been lurking on this list for some time, trying to drink from the 
fire hose. Now, I have a few questions. First, though, here is the 
background:

I work for a testing facility where we test telephony products. We have 
been using Asterisk for about 4 months now as a test bed for various 
things. Now, our test engineers want to ramp things up a bit.

Essentially, the system under test has the capability of using up to 8 
T-1 ISDN/PRI lines. The engineers want to build two Asterisk "clusters", 
each with 20 ISDN/PRIs. Of these, 12 would be "Inbound" PRIs, and the 
other 8 would be "Outbound". The system under test would be connected to 
8 of the Inbound lines, and a Call generator, such as an Ameritec 
Crescendo, would be connected to the other 4 Inbounds. These twelve 
lines would dial through the Asterisk, through the 8 Outbound lines to 
the other Asterisk, which would terminate the 8 PRIs into 12 PRIs worth 
of Crescendo or Fortissimo.

The whole purpose of this mess is to determine how the system under test 
responds to network congestion, since it is competing with the Crescendo 
for the 8 Outbound PRIs.

So, I guess my questions are:

1) Is Asterisk's congestion capabilities robust enough to do what we want?
2) I have the resources to build this cluster one of two ways:
a) I have 4 Dell PowerEdge SC1600's, with 3.0 GHz Dual Xeons (looks like 
4 processors to the system), 2 GB of RAM, and 6 slots (2xPCI, 2X PCI-X, 
2X PCI-Express). I would use these and put 5 Digium cards in each for 
the two Asterisk clusters.
b) I also have 12 1U rackmounts, 866 MHz, 1 GB RAM each. If I used 
these, I would put 1 Digium card in each and organize them into two 
groups of 5 Asterisk servers.

For #2, which would be better/easier, a or b?

I would appreciate any insights anyone may be able to provide.

Mitch Thompson

-- 
"Nothing is more destructive of respect for the government
and the law of the land than passing laws which cannot be 
enforced." —Albert Einstein