This is using PIX firewall 525 with v6.3, and a Cisco router 3700. I'm thinking of work with my contractor for the implementation of Voip. I know nuts about Voip. But, according to my contractor, this voip is using sip. I also heard that 2 vlans - one for data, one for voice are needed.
I'm more concern about what had need to be done on the firewall? router? switches?
Anyone can guide me what to be done on the above equipments, possibly with other requirements, such as, public IPs?