An article at VoIP Weblog suggest that the old telcos may have actually been blocking access to 911 for some VoIP operators. Smithonvoip is similarly aghast that 911 services which exist to provide access to emergency services could have been blocked.

When the child was in medical distress, it’s mother called 911 on a VoIP telephone from the family home but an ambulance took 30 minutes to arrive after being sent to the family’s previous address. The reason for this was that the emergency center looked up the number and used the address on file. This address, however, had not been updated after the family moved.

Unlike traditional POTS landlines which give emergency call-centers instantaneous location information based on the physical telephone line in use, VoIP telephones route their calls via the internet and can only provide location information given in a separate record.

At the moment, in many cases, it is necessary for the VoIP user to update their location information with their provider.