Our website currently restricts a cookie-based session to the IP address that was originally sent the Set-Cookie HTTP header. In the past a user's IP would rarely change, so this didn't present much inconvenience. However, some of our clients accessing via 3G devices are experiencing session failures due to this IP restriction.
I know little about the network infrastructure used for mobile networks. Do the majority of providers attempt to route connections to a common public IP in order to maintain compatibility with websites like ours, or should I consider restricting sessions to an IP range instead?