From time to time, the Computing Services Centre (CSC) reviews the size of the modem pool as well as the number of lines provided in each group based on the utilisation statistics collected and the budget available. To ensure effective use of the University resources, starting from Semester B 2003, the staff and the student modem pools have been merged together to form a single large modem pool. As the new modem pool can be accessed by using the same prime numbers previously adopted by the respective student and staff modem pool i.e. 24704400 and 24704402, thus there is no need to change the dial-up settings of the PCs of staff and students. Calls made to these prime numbers will be automatically transferred to the new modem pool.

In addition to the existing groups of 30-minute lines and of the 2-hour lines, a new group of 2-hour campus-only lines with prime number 31809700 has been implemented such that those dial-up users who have the genuine needs of accessing resources on University servers only will have a better chance to get connected. Computers dialing in through these campus-only lines can only access machines locally connected to the campus network (i.e., machines bearing CityU's IP addresses), and access to machines outside campus or on the Internet will be blocked.

CityU modem pools and corresponding dial-up numbers are listed in the following table:

Modem pool	Dial-up numbers
2-hour dial-up lines	24704400 or 24704402 (formally staff only number) 02:00 - 08:00 No time-out 08:00 - 02:00 (next day) 2-hour time-out
2-hour campus-only lines	31809700 02:00 - 08:00 No time-out 08:00 - 02:00 (next day) 2-hour time-out
30-minute lines	24704401 02:00 - 08:00 No time-out 08:00 - 18:00 2-hour time-out 18:00 - 02:00 (next day) 2-hour time-out