Relevant Applications

App	Type of Data Being Sent	Streaming/Non-Streaming Data?	Average/Max Bit Rate (in Kbps)*
Audio	.mp3 .rm .wav	Audio files can be streamed or downloaded asynchronously. Users are probably slightly more likely to stream than to download since audio files are often embedded in web sites and users often like to try out their sound files before saving them to the hard disk.	mp3: 56K/256Kbps wav: 56K/256Kbps rm: 56K/256Kbps
Video	.avi .mpeg .mov .ram files	Same as above	400K/1.5Mbps
Email	Usually .eml files; however html files with embedded pictures are becoming more common. File attachments are also frequently used.	Minimal.	0/400Kbps (almost all of the time, e-mail usage is someone typing an e-mail or reading an e-mail. The bit rate is always at its maximum for downloading an e-mail or sending an e-mail)
Web	Mostly .html files	More and more streaming is needed due to the rise of websites with Flash, Shockwave, and Java components that contain actual code and procedures for the endpoint to run.	56K/1.2Mbps (note that most of the time, people are reading web pages. Surfing between pages only happens for a small fraction of the time.)
Office Apps/System Administration/Database Work	Surfwatch entries, Access files, etc.	Not usually	160K/800Kbps

* In order to estimate the average Kbps required for multimedia files, we divided the physical size of various files by their length in seconds. Of course, depending on the amount of compression, bit rate varies greatly even within the same file format, although some formats tend to be more densely packed than others. In addition, since sound and video files are usually for entertainment purposes and therefore of relatively low priority and since many media players allow the user to allocate a large buffer on the hard drive, we inferred that it wasn’t absolutely necessary for the streaming to be totally "smooth" all the time. Thus, we moved our average slightly below the average multimedia file’s required Kbps. With other types of applications, we drew upon our vast experience in web surfing and file downloading to help us determine what bit rates are "comfortable" for the average web site.

To obtain the maximum bit rate, we simply envisioned the largest realistic bandwidth demand that could exist for each of the applications.

User Types

User Type	Apps Used Most Often	Frequency of Network Use	Average/Peak Bandwidth
Student	Audio, Video, Web, and Email	Students can conceivably be logged on at any time. However, from 3-8am, almost all students are asleep. From 8am until 3pm on weekdays, there is moderate network use due to classes. From 3pm until midnight, use steadily increases, with sharp peaks before and after dinner and from 9pm until 12. From 12am until 3am, network use slowly winds down. During the weekend, students’ network use is probably fairly light during mild weather but may become moderately heavy during cold or inclement weather. Since many students use the network primarily for recreation, usage should decline during midterms and finals.	Students probably require the most bandwidth since they use the most demanding applications and multitask network applications quite often. 10 Kbps/1 Mbps for every student logged on at a given time (note that the average usage takes into account the fact that every student is idle most of the time. The maximum usage is an absolute maximum, not necessarily the maximum that a student could get at any point in time.)
Faculty	Web, Email, and Office/ Database/ Admin	Most faculty are only in their offices for maybe four or five hours a day at the most on weekdays only. Actual network use varies greatly from member to member, but an average of about an hour a day seems reasonable since all must at least check their email periodically. Since they frequently don’t even have offices, the demands of part-time faculty are nearly negligible.	Most faculty network use is not recreational and relatively light. 10 Kbps/800 Kbps per faculty member
Administration	Web, Email, and Office/ Database	Administrators are in their offices from about 8am until 5pm every weekday, with an hour lunch break in between. We can assume that they are using the network for perhaps 20% of that time, or about 1.5 hours a day.	10 Kbps/ 1 Mbps
Staff	Web, Email, and Office/ Database	Depending upon their department, some staff members may not use the network at all. Clerical staff members are probably similar to administrators in their demands.	10Kbps/1Mbps

External Users (includes visitors to gcc.edu site and dial-up connections)

Office/ Database, Web, Email, Audio, Video

The Grove City College external site probably gets several hundred hits a day, especially during the months of October through December, when high school students are preparing their college applications. Every commuter and professor has a dial-up connection. Traffic on the dial-up is practically nonexistent during the weekday since everyone’s on campus, but resembles a scaled-back version of the student model on nights and weekends.

28.8Kbps/56Kbps (most outside visitors still connect via modem)