I simply replace my rr modem with this one and power it up . the speed be cripple and when I try to bring up a web page , I be present with a message `` you MAC address be unknown , please call twc\/roadrunner and give the Agent the new MAC address '' . I call the number give and after 10 minute get ahold of a technician who take the new MAC address and assign it to my account . within a few moment the modem disconnect . I unplug it and plug it back in , and when it come up , I be at full speed again . my d\/l speed go from 8mb to 11mb and my ping drop from 39m to 21 ms.