+ 0 Votes E1 or T1 robert.sebastian 6 years ago Pending your throughput requirements you should size the circuit accordingly. Would also recommend staying with the same provider/carrier for all locations. As long as data stays on the same provider/carrier's backbone VPN's over the internet are fairly stable and secure. My experience with DSL has not been good due to Quality of Service issues and mean-time-to-repair. In the states T1's to the internet are fairly cheap and stable. We use Cisco 2800 series routers tunneling all traffic back to a central point.Applied liberal use of ACL's to control and dispose of unwanted traffic, maintain QoS and set encryption.