All Ford Prefect needed to travel the universe was a towel, a resistance toward panicking and The Hitchhiker's Guide to the Galaxy. But here in the real world, you need much more to travel the globe while maintaining connectivity to the office, particularly if you're trying to access the Internet from places faraway from your desk. Or you can dial long distance, which, if you're traveling internationally, can clock phone charges that will make you the target of the expense account troll's undivided wrath. Or you hope business can wait until you get back home, and not dial in at all. The concept is similar to roaming when using your cell phone or your ATM card at other banks.
Internet roaming is intended to be seamless.
After the user is validated and authorized, logon is allowed. The settlement software tracks the relevant details of usage, including connection time, so the service deliverer can be paid for services rendered. Both offer ISPs the software that provides the user authentication, authorization, accounting and settlement functions required for roaming. GRIC, in November. Both have strong roots in Asia, where there's a highly regulated telecom and Internet market, but they are expanding with somewhat different business models and services.