Selection of particular router

[virenderpalsingh]

I wanted to know how do you select router for a particular type of network like

a) I have worked on 1721 VPN router what could be its replaced

b) Is there any document how the router series goes like which is low series router & which is higher.

c) Any document on common router used in market these days

[jmia]

Go here:

http://www.cisco.com/en/US/products/hw/routers/index.html#products