How reliable is the 911 service on VOIP phones?

[JodyGelb]

I have recently got rid of my Embarq phone service at home and have switched to ITP VOIP which is cheaper and better. However, I have read a lot about how 911 service doesn't always work well with VOIP. Can anybody with a VOIP phone service who has attempted to call 911 on it before tell me if it actually worked or not?

[Albert]

All Internet Phone services providers are supposed to be setup so that they support 911 (or E-911) services in case of emergency. Normally you see, with a traditional phone line, if you call 911, they can tell where you are calling from. But this same ability does not exist with a VOIP phone, so you need to register your VOIP phone with the service so that if you call 911 from your VOIP phone, the emergency responders will know where to go.

[Alex]