Hi all,
I have few APs which are connected to Central location, Central service. Now I have this setup, so I need to upgrade it. Can you recommend me what to do? Whato to add, how to connect, via switch or...?
Thx
Fewi, I forgot to say thank you... So, Thanks you!That's much better information. If you're good with buying and reading some books (which I'd recommend) I'd suggest "Top Down Network Design" from CiscoPress. Ignore the vendor specific information, the ideas in the book are excellent and apply to any network.
If you are looking to be scalable I would recommend the classic three tier access-distribution-core model. Each router that customers connect to directly is an access router. Multiple access routers connect redundantly to two each distribution routers. The distribution routers connect to your two core routers redundantly. Then introduce an ISP zone with routers connecting to the Internet, redundantly linking back to the core.
The most important idea for the core is that it is simple. It consists of high speed links and high speed routers that are designed to route packets as fast as possible. Any security to/from the Internet is handled on the SP (service provider) edge by that dedicated router. The core doesn't have to inspect packets, it just routes them. The core also doesn't have to secure customers, that security is run on the access routers (or, in the case of EoIP tunnels to a Hotspot, on the Hotspot router).
By now you're wondering how this scales better. You can run - for now - your services in the core. Your proxy server, web server, and RADIUS servers connect directly to the core routers as central services and be used more or less like they are now. If the load becomes too big you simply install one proxy server, web server, and RADIUS server per distribution pair of routers. Now every access router (and its customers behind it) use those services within their distribution block, and that traffic doesn't have to traverse the core at all. When you're bringing up more access routers you introduce new distribution blocks with two routers each that connect to the core, and replicate the services (proxy, Hotspot, RADIUS) - though you could argue that RADIUS is a network global service that doesn't take much traffic and should always be provided off of the core for truly central user administration; you can introduce proxy RADIUS servers per distribution block that talk back to a central database backend for users.
This model scales extremely well, and is very commonly used in large campus designs. It helps to think of this as a campus, in fact. Each distribution block is a house on a campus. The houses contain in their basement a couple of big redundant routers that route all traffic for the building to other buildings via the core. The houses also have smaller routers per floor that users connect to. The core connects the different buildings to one another, including one (or more) building(s) where the campus connects to the Internet. If you've got more wireless/wired users coming in and a distribution block and its services are getting overloaded it's equivalent to a building on the campus being full. The obvious solution is to build a new building (a new distribution block) and move users into the new building, which contained in itself can provide all the services they need.
Once you've got your network built this way bringing up new distribution blocks is fairly easy. Just make sure you get your IP addressing right - ideally you want to be able to summarize each distribution block in the core so that there's just a few, simple routes.
Again, the book I recommended goes into this design in great detail.