As voice over internet companies go out of business the FCC decided there should be some warning for customers, unlike the surprise received by Sunrocket customers.

The FCC approved a rule yesterday that mandates that struggling VoIP companies must give customers and regulatory bodies “reasonable notice” before they shut down. The rule is meant to avoid a repeat of the sudden SunRocket shutdown in July 2007 that left thousands of customers without any phone service, including access to 911 and other emergency numbers.

But the FCC did not specify the amount of time a VoIP provider has to provide its warning, so for now the vague “reasonable notice” timeframe is up for interpretation.