Could someone help clarify my understanding of VoIP using CISCO hardware?
From what I can tell:
ATA Connectors connect legacy hardware e.g. Fax Machines / Older telephones to the VoIP system
VoIP phones are used with VoIP (ATA connections for older phones)
VoIP compatible routers and switches carry the signal back to the IP-PBX server, which is a PC dedicated to being the VoIP exchange for a company
Data then travels to another VoIP compatible phone in the organization, or to a VoIP gateway if it requires a phone-call with the offline world
I'm looking into enterprise-size solutions, with approximately 1000 phones. I have heard that Asterisk is the open-source leader in software for VoIP servers, however I don't understand what software on a VoIP server does, and what hardware connects the VoIP server to the phone network. I've seen a lot of details of the likes of 8-Port FCX (iirc) PCI cards for VoIP servers, but I'm not sure what these do either.
I'm looking into CISCO because Asterisk isn't scalable; as in, it won't perform load balancing and targets a phone system of <2000 phones, if an organization was to grow to more than 2000 phones it would need to look into something like CISCO anyway.
Could someone write the steps it takes a call to go through the hardware from one VoIP phone to another?