DOCOMO Reports on Effects of and Response to sp-mode Service Malfunction


TOKYO, JAPAN, December 27, 2011 --- NTT DOCOMO, INC. once again extends its deepest apologies for inconveniencing customers as a result of its sp-mode service malfunction on Tuesday, December 20, 2011, causing the email address of some customers using the service to be temporarily replaced with a different email address and related errors.

This situation was resolved by around 18:00 JST on December 20*. The resetting of packet switching equipment, performed as a precaution, was fully completed by around 01:00 JST on December 22.

All sp-mode services that had been temporarily suspended as a result of the malfunction were restarted by around 14:00 JST on December 22, with the exception of the phonebook backup service, which was restarted at around 12:00 JST on December 26.

DOCOMO has completed its analysis of the effect of the malfunction on customers, as explained below, and is now addressing inquiries from individual customers. Considering this incident to be very serious, DOCOMO is taking all necessary countermeasures to ensure the malfunction does not occur again.

*There is a possibility of a replaced email address remaining in the “My Address” category in the sp-mode application after 18:00 JST on December 20, but emails can be sent or received normally because the information on the network has been corrected. Addresses displayed in the “My Address” category can be corrected by refreshing the “My Address” information.

  • 1) Reason for Problem
    Mismatches between phone numbers and IP addresses on the sp-mode server occurred as a result of congestion on the server on December 20.
  • 2) Details
    The malfunction caused the email address of certain sp-mode service subscribers to be temporarily replaced with a different email address.
  • 3) Customers Affected by the Malfunction (see Attachment)
    Customers whose email addresses were changed are as follows:
    1. Customers (A) whose email address was changed to another email address: 6,878 persons
      Note: Of these, customers who did not send and/or receive an email, and were only inconvenienced by the changed address: 4,097 persons.
    2. Customers (B) who received an email from Customers (A) in which the sender’s address was that of another email address: 2,909 persons.
    3. Customers (C) whose email address was replaced with the address of someone in the Customers (A) group: 6,894 persons.
      Note: Of these, customers who did not send and/or receive an email, and who were only inconvenienced by the changed email address: 4,110 persons.
    4. Customers (D) whose email addressed to Customers (C) was received by someone in the Customers (A) group, when the devices of Customers (C) was turned off or had no reception: 2,017 persons.
  • 4) Response to Customers
    • DOCOMO will publish an apology in newspapers and send direct mail to individual customers determined to have been affected.
    • DOCOMO will set up a designated call center to respond to inquiries about the matter.
    • Customers may contact the Designated Call Center as follows:
      Dial 0120-152-770, including from mobile phones and PHS devices.
      Open from 09:00 to 20:00 JST daily, including Saturdays, Sundays, holidays and the yearend/New Year period between December 27, 2011 and January 31, 2012.
  • 5) Refunds Due to Temporary Suspension of sp-mode Service
    • DOCOMO will issue refunds by subtracting the daily rates for the number of days on which services were suspended from the monthly fee. The applicable services are docomo Drive Net™ and imadoco search™.

Note: DOCOMO will issue an announcement regarding specific refund dates and methods as soon as these are determined.

(Reference) Temporarily Suspended sp-mode Services

(Attachment) Malfunction of sp-mode on December 20, 2011

NTT DOCOMO is a world-leading mobile operator that is in transition into an Integrated Service Company placing mobility at the core. The company serves over 59 million customers in Japan via advanced wireless networks, including a nationwide 3G network and one of the world’s first commercial LTE networks. Leveraging its unique capabilities as a mobile operator, DOCOMO is a leading developer of cutting-edge technologies for NFC mobile payments, mobile GPS, mobile TV, intuitive mobile assistance, environmental monitoring, smart grids and much more. Overseas, the company provides technical and operational expertise to eight mobile operators and other partner companies. NTT DOCOMO is listed on the Tokyo (9437), London (NDCM) and New York (DCM) stock exchanges. Please visit for more information.

sp-mode is a trademark or registered trademark of NTT DOCMO, INC. in Japan.
sp-mode is only available to subscribers in Japan.

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