Answer: There are several possible causes for slow downloads but the most probable is somewhere between your local computer and the computer you're connecting to there is a bottleneck of a lot of network traffic and that slows the speed of the internet to a crawl.

The internet experiences rush hour just as our highways do. The internet has a finite capacity and if a lot of people are trying to move data around at the same time, everything slows down. Typically, rush hour occurs Monday to Friday in the afternoon to early evening. Sometimes the internet comes to a standstill and you will be unable to even make a connection to a web site. It's frustrating. One reason the internet becomes crowded is the billions of emails that are sent every day. And 80% of those emails are spam.

If you need to download files try to anticipate your needs and download late at night or early in the morning.

Other reasons for slow downloads or problems connecting with a web site:

1. Web sites that offer file downloads can become overwhelmed with download requests. These servers have a maximum number of connections that are allowed at the same time. Once that number is exceeded connections are not allowed and users get a time out error message. If the file server is at its connection limit, sometimes you can keep clicking on the download link and eventually you'll make a connection. Sometimes. Murphy's Law of file downloading says the more important the file and the closer you are to a deadline, the greater the chance you will not make the connection.
2. When you make a connection with a remote computer to download a file, you don't make a direct connection with that computer but rather you make a series of connections with intermediate computers between your origin and your destination. We call these hops. There may be 10-15 hops between you and your destination. The overall speed of the internet connection between the origin and destination will only be as fast as the slowest hop. The slowest hop could be on the Geography department network, on the College network, on the CUNY network or anywhere else between you and your destination.
   • There are tools a systems administrator (and you) can use to test the speed of all the hops but sometimes these tools won't work on computers on the internet because the local systems administrators turn off this troubleshooting feature. They do this because denial of service attacks can target this feature.
   • Here's an example of a Unix command called traceroute that is tracing the number of hops between our file server everest and www.sun.com:

     traceroute www.sun.com
     traceroute to www.sun.com (209.249.116.195), 30 hops max, 40 byte packets
     1 cumulus.geo.hunter.cuny.edu (146.95.2.250) 0.738 ms 0.511 ms 0.493 ms
     2 geocisco.geo.hunter.cuny.edu (146.95.47.18) 1.075 ms 0.962 ms 0.945 ms
     3 10.95.0.49 (10.95.0.49) 0.922 ms 0.863 ms 0.790 ms
     4 128.228.93.170 (128.228.93.170) 2.262 ms 2.759 ms 3.249 ms
     5 172.30.12.1 (172.30.12.1) 2.424 ms 21.442 ms 2.668 ms
     6 172.30.17.7 (172.30.17.7) 1.831 ms 1.872 ms 2.148 ms
     7 128.228.95.34 (128.228.95.34) 49.349 ms 6.478 ms 3.373 ms
     8 128.228.95.3 (128.228.95.3) 6.152 ms 4.721 ms 3.523 ms
     9 * 128.228.96.1 (128.228.96.1) 2.497 ms 1.922 ms
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