I'm currently planning a network and need to know the best hardware solution for a firewall/router. The only hardware I'm familar with are el cheapo routers you buy at Staples. I will need something more robust that will handle traffic for upwards of 20 servers, 60-80 clients with one or two T1 data connections. I'm unsure of the amout of bandwidth we'll be using but it would be good to err on the high side. Would be running an Exchange server, possibly web server.
Things we need it to do:
SIP protocol support. Will be passing VOIP traffic through this.
Want something that will work well in the future.
Would one box do all of this or would you need 2? Nat + Router? I'm unsure.
Please advise a networking newbie.