Basic User: Web Browsing, Email, File Downloading, Instant Messaging
These activities are pretty much the simplest thing that someone can do on the Internet. Since all these activities require that the user initiate a request to a server on the Internet to load a web page, check email, etc., the router's firewall will not cause problems. Assuming you can get the router connected successfully, you probably won't encounter problems with it thereafter.
Recommendation: Most any router will work. Make your decision on price, warranty, and quality of the manufacturer's support.
Remote office worker / Telecommuter (VPN User)
These users will usually need to have a secure Virtual Private Network (VPN) connection back to their company network. Most routers support some sort of VPN client pass-through connection, but that may not be enough, depending on the needs of the VPN server that you're trying to connect to and the VPN client
If you fall into this category, you'll probably also use some sort of Internet conferencing (WebEx, GoToMeeting, etc.) and/or telephony (Skype, Gizmo, Vonage, etc.) application. Fortunately, these applications have become a lot smarter about working around NAT firewalls and you generally shouldn't have problems using them.
If you are self-employed or work for a smaller company, you'll probably be on your own to figure out a VPN solution. Fortunately, there are a number of products available with VPN endpoints built-in that can take some of the pain out of making a secure remote connection. Use the VPN filter checkbox on the Router Charts to narrow the list.
One recent development that takes a huge amount of hassle out of setting up secure remote access is the appearance of products with SSL-based VPNs. Instead of hassling with installing and configuring IPsec or PPTP clients, all you do is launch a web browser and log into the router. The browser downloads a Java or ActiveX-based client that then automatically sets up a secure SSL connection. The Linksys RVL200 [reviewed] is a good example of this new class of SSL VPN router (Figure 2).
Figure 2: Linksys RVL200
If you run a VPN client on your computer or notebook, your router must support VPN pass-through for the VPN protocol that you are using. The three common VPN flavors are PPTP, IPsec and L2TP. Most current-generation routers support VPN pass-through for these protocols. But if in doubt, check the "Supported Protocols" section of the specs of the products that you're considering.
If you're trying to set up your own VPN solution to securely access your home LAN when you're away, you'll need a router with a VPN endpoint built in. Most of these routers are IPsec-based and will require an IPsec client. So check to see if the router includes the license(s) you need. Otherwise, you'll need to buy one for each computer that needs secure remote access. A few VPN routers also have PPTP servers built in, which can use the PPTP client built into all versions of Windows.
Finally, if you're trying to set up a secure site-to-site (or LAN-to-LAN) link, you'll need two VPN endpoint routers, one for each LAN. You'll have the fewest hassles if you use the same router on both ends of the connection. This means you'll have only one VPN configuration method to learn and give you the best chance of success, should you need to call the router manufacturer's tech support.