I'm looking to deploy an ASA-5510 as our internet firewall. We'll be using a DS3 coming into a Cisco 3845 router and we want to service 4 different, NATed networks. My question is, can the ASA-5510 with a Base license service the needs of all three networks, or do we need to upgrade and enable security contexts? If we don't need them, are there any advantages to having security contexts in this situation? Thanks.