NCDesk
Technical Notes - Proposed Network Requirements
In testing mode, NCDesk requires the presence of a stable connection with the Internet to function properly. This means that each client must have TCP/IP networking capability. Each client must be properly configured such that it may reach sites on the Internet. This requirement assumes the presence of a properly configured gateway, access to DNS servers, etc. Either DHCP obtained or statically set IP numbers may be used, however clients should maintain their DHCP leases for the duration of the test session.
NCDesk is a real-time secure testing environment, therefore no attempt to cache its content should be used. Firewalls, proxy servers, etc. should be configured to pass traffic on remote TCP ports 80 and 443 for data.ncsu.edu, the test server. Traffic may not appear to be web based (http and https) to some packet inspecting appliances and software.
Network requirements for the test depend almost exclusively on two variables, the number of students to test, and the bandwidth of the network . Having more students concurrently taking the test than the local network can sustain will lead to slow responses during the test and produce a negative experience with the test. More information on this topic may be found under Bandwidth and Network Usage.
Wired vs. Wireless
There are no restrictions on the types of wired networks
supported. However, wireless networks should have WEP (wired equivalent privacy)
enabled on all wireless network devices in schools using wireless to access
NCDPI online testing materials. 64-bit encryption should be used versus the
lower security of 40-bit. WEP is included in all major wireless network devices
of any recent manufacture, and is extremely easy to deploy. This level of
security takes place in the two lowest levels of the "OSI model" which
modern networking is based on, and therefore does not offer end-to-end security.
The WEP protocol algorithm has also been broken, making WEP vulnerable to exploitation.
However, the effort needed to exploit this weakness is extremely high, and
using WEP provides a large "first
wall" of defense for a wireless network, combined with the characteristic
of being nearly universally available and easy to deploy.
To provide true end-to-end security and encryption, and also to provide a second level of defense towards data privacy, SSL (secure socket layer) encryption is deployed on the servers delivering the tests themselves. This encryption operates directly between the servers and the individual applications that students and administrators use to access online tests and test materials. Thus, even if a school network were to be compromised, high level encryption (128-bit) is still present on all data end-to-end, protecting it even if the network itself were to be "hacked". Other security methodology can be used for even greater protection at the school-level, such as the use of VPNs (virtual private networks). However, this is beyond the scope and need of NCDPI test delivery policy, and should be considered by schools on a case-by-case basis depending on their security needs. NCDPI does not require such additional security measures to access test materials.
This file was modified on Wednesday, August 29, 2007; at 1:36:41 PM