You have certain very important and specific personal responsibilities
under the University's Computer and
Acceptable Use Policy.
These include not obstructing others' use of the
network by consuming
excessive amounts of system resources, including
To maintain network performance Columbia University Information Technology
has implemented an automated network
bandwidth quota system, described below. Individual
computers may be limited in either the inbound or outbound
direction. Limits are imposed only on off-campus traffic to
or from the Internet. Traffic on the University's internal
network is not restricted in any way. Internet2 traffic is
also unrestricted. The quotas ensure that a very small minority of users cannot monopolize and degrade our network connection to the Internet.
The parameters of this system may be changed
without prior notice in order to ensure proper
functioning of the network for the greater
Each host computer on the Columbia network is
assigned two quotas. One quota affects outbound
usage, i.e., data sent to the Internet. The
second affects inbound usage, i.e., data
downloaded from the Internet. A host exceeding
either limit in a given hour will have its
bandwidth in that direction restricted to a lower
rate for the remainder of the hour and the hour
following if excessive bandwidth use continues.
The quotas change from time to time in order to
allow the highest traffic levels compatible with
the overall performance of the network.
You may check the current hourly quotas and
whether the computer you are currently using
has been limited at
Bandwidth Quota Check.
If you find that your host is often exceeding
either quota, it could be due to any of these reasons:
- Your host is running a p2p application such as
KaZaA set up for unlimited serving of your
- Your host has been compromised by a worm or virus.
- Your host is connected to Columbia's network via a wireless
router, and your neighbors connect to the router via wireless. In this
case, the combined traffic of your and your neighbors' hosts exceeded
If you run a server that has a legitimate academic or University
business need for greater Internet bandwidth, it will be
added to the list of exceptions. In consultation with University-wide
IT staff, most university, school and departmental servers
that need to have already been placed on the exceptions list.
If you are responsible for a web, streaming media, or other
file server that you would like added to this list, please
contact your local IT group, if you have one, or notify CUIT
by using the request form at Network
Quota Exception Request.