Japan is one of the most sophisticated optical broadband country, but unfortunately, the optics cannot be used in case of power outages. So the fixed line are affected by blackout pretty seriously. Source: WirelessWire News, 3/14

Services expected to be unavailable in case of blackout

KDDI

(For consumers)

Telephone: au Hikari, telephone, KDDI-IP Telephone/050 service, Cable Plus Telephone, Metal Plus Telephone (if a user use his/her own power), ADSL one Telephone Service (if a user use his/her own power), MyLine, MyLine Plus (if a user use his/her own power)

ISP: au Hikari Net Service, ADSL one, Metal Plus Telephone, Dial Up, au one net
Other: au Hikari TV servic

(Enterprise)

Telephone: KDDI Hikari Direct, HDDI Hikari Direct over Powered Ethernet, KDDI Metal Plus (wholesale), KDDI-IP Phone
ISP: KDDI Internet Gateway, Ether Share etc.
Intra Net Service: KDDI Wide Area Virtual Switch, KDDI Powered Ethernet, KDDI Ether-VPN etc.

NTT East (local service)

Telephone: Hikari Telephone, ISDN, analog telephone (if a user use his/her own power)
ISP: Flet's Hikari, Flet's ADSL, Flet's ISDN
Business Service: Business Ether, Flet's VPN, PBX, Key-Telephone

NTT Communications (long distance)

Telephone: OCN Dot Phone, Hikari Line (Arcstar Direct etc.)
ISP: OCS
Enterprise data service: IP-VPN, e-VLAN, dedicated line etc.

Michi