Goodbye ACB, hello ISP!

Following a discussion at the Executive Board meeting on March 30, the Director General has endorsed a new approach to connecting to CERN from home. With access to the Internet universally available via Internet Service Providers (ISPs), the Automatic Call Back (ACB) service will be phased out by the end of 2004. Phase 1 will start on July 1, when the "call back" and the toll-free numbers will be stopped, and a temporary restricted dial-in service, available until the end of the year, will be introduced to leave users enough time to make the change. It should be noted, however, that the telephone costs will be at caller's expense starting in July. Therefore, ACB users are encouraged to switch as soon as possible to ISPs which provide equivalent or better service.

The ACB service is used for accessing CERN's network and the Internet via telephone lines from outside CERN. Technology has greatly evolved since ACB was introduced, and ISPs now provide equivalent modem or ISDN service at low cost, and can also enable users to connect to the Internet from other locations than home (hotels, conferences, wireless hotspots, etc.). Some ISPs even offer free services. In addition, the arrival of ADSL¹ gives the possibility of much higher speed connectivity from home. Over the last year, many ACB users have switched to ADSL due to its greater convenience.
The decision to phase out ACB is mainly prompted by security concerns. Direct connections to the CERN network from external computers which are not managed by CERN were traced as the source of several serious virus and worm attacks on the CERN network in the last year. Reducing the impact of this security hole is an increasingly urgent matter, as virus attacks continue to grow in sophistication and frequency. Connection through ISPs reduces the direct exposure of the CERN network to security risks. In addition, ADSL enables faster and more convenient security updates, thus improving security for the user as well as for the CERN network.
Another reason for phasing out ACB is its significant cost to CERN departments and visiting teams in terms of phone bills, and to IT to run the service. Where justified, CERN may reimburse part of the associated cost of using an ISP. For example, for people working from home on a piquet service, the general guideline for reimbursement is 50% of the monthly ADSL charge via a single annual claim.
In order to ensure a smooth transition, ACB will be switched to a restricted dial-in service on July 1 when the call back and toll-free numbers are phased out. The situation will be reviewed in October, with a view to closing the dial-in service at the latest by the end of the year (or earlier in case of security problems). All ACB users who have used the service in the last six months will be contacted by email, and provided with simple guidelines on how to make alternative arrangements, depending on their needs. These instructions will also be made available and regularly updated on the website: http://www.cern.ch/acb.


¹ ADSL (Asymmetric Digital Subscriber Line) requires a special modem, usually provided for free by the ISP, which works by splitting a telephone line signal into two, one for voice and the other for data. Users pay a fixed monthly charge for unlimited internet surfing, e-mail and chat etc. The user does not have to pay any metered telephone charges and can still make and receive telephone calls as usual. Most ISPs offer several data rates at different prices. Typical ADSL subscriptions start at about 15 euro/month.