Answer:
All 360's, and original xbox's can go on xbox live
An Xbox 360 Arcade does possess the bare essentials needed to log onto Xbox Live and conduct online gaming. However, this may put a strain on the limited resources that come with an Arcade unit. Obtaining some other means of storage is recommended. Ordinarily, this would mean a Memory Unit or a Hard Drive Unit, but a recent software update also allows the use of USB Mass Storage devices (memory sticks, card readers, hard drives, etc.) to an extent.