These web services are useful for mathematics, but are blocked on some campuses because of high traffic or perceptions that they are not useful for education.

Youtube.com
Youtube is host to many academic and training videos, as well as funny videos of people falling down. This service may be blocked because the network does not have enough capacity for multimedia traffic.

Skype.com
An Internet video call is an effective way for two or more people at distant locations to have a discussion. Mathematicians and teachers, like everyone else, need to collaborate to advance their craft. This service may be blocked because the network does not have enough capacity for multimedia traffic.

Elluminate
Sas.Elluminate.com is an online conferencing service. An online conference is an effective way for a group of people at distant locations to have a meeting. Mathematicians and teachers, like everyone else, need to collaborate to advance their craft. Elluminate needs Internet ports that may be blocked by a campus firewall or Internet proxy. The service is used to host online academic conferences, e.g. a weekly conference about mathematics on the web.

ftp and sftp Protocols
ftp is a traditional method of transferring or sharing files. sftp is the secure version of the protocol. Both are commonly blocked. Many file hosting sites offer http and https as alternative protocols for download files.

Wireless Access from Linux Laptop PCs
Some campuses require installation of a Windows DLL in order to make a wireless Internet connection. This policy blocks Internet and LAN access for all laptop computers, net books and other mobile devices, that have non-Microsoft operating systems, including Linux, Unix, Macintosh OS/X and Chrome. Many mathematicians, scientists and programmers prefer Unix and Linux operating systems, because of the application programs, publishing software and other tools that are available.

P2P Networks
Some campuses block every Peer-to-Peer Network that is know to them. P2P protocols are an efficient method of distributing large files, and have great potential for legitimate academic use.

File Sharing Hosts
Some campuses block host-based file sharing services. These services are a popular method of distributing files, and have great potential for legitimate academic use.