Hardware for 180 concurrent connections


I was hoping someone could help me with the spec of a asterisk server.

We are looking to put an asterisk server in to the call flow between a legacy PBX and the pstn network to enable us to do a db lookup each time a call is routed externally, using a fastagi script (which will sit on a separate server). The legacy PBX currently connects to PSTN via 6 PRI cards (180 channels) so from my understanding the asterisk platform to intercept the calls we will need 12 PRI connections.

My question is

What type of hardware spec would we need to accommodate 180 concurrent connections and is there a Pre built hardware option such as one of the digium products that we could look at?

Also is there a hardware option that allow the calls to be directly routed in the case of a hardware problem with the asterisk system.

It’s also worth noting that the legacy PBX doesn’t support SIP so that’s not really an options for connecting them up.