Network Performance - Impact On Networked Educational Software

Objectives

What we have found

NSFNET backbone dataset

• Traffic favouritism high -> geologically uneven distribution of network traffic
• Link delays increase subtantially
• Migration of FTP and other services to WWW
• Traffic volume increases quadratically

Fig 1.1 Extrapolated total traffic in byte count
Source : ftp://ftp.nic.merit.edu/nsfnet/statistics, Graph by : James Pitkow, GVU Centre

(a) ANSNET T3 Delay Matrix Report for January 1993
Filtered Median Delay Times (ms)

	128	129	130	131	132	133	134	135	136	137	138	139	140	141	142	143	144	145	146
128
129
130
131									14,1							33,1
132
133																43,1
134										5,1	16,1
135				33,1		43,1					30,1
136				14,1										26,1					2,1
137							5,1
138
139						28,1
140																			24,1
141																		26,1
142					21,1
143				33,1		43,1
144
145				14,1											30,1
146

(b) ANSNET T3 Delay Matrix Report for April 1994
Filtered Median Delay Times (ms)

	128	129	130	131	132	133	134	135	136	137	138	139	140	141	142	143	144	145	146
128		32,7												37,7
129	32,7													18,7	22,7	24,7	32,7
130														19,7	23,7
131														25,7	29,7
132														24,7	28,7
133														33,7	37,7
134														31,7	35,7
135
136														46,7	50,7	49,3
137														29,7	34,7
138														38,7	42,7	44,7
139														25,7	29,7	31,7
140														23,7	27,7	29,7	37,7
141																		46,7	45,7
142																		50,7	50,7
143																			48,3
144
145														46,7	50,7
146														45,7	50,7	48,3

Table 1.1a & b ANSNET T3 Delay Matrix Report
Data source : ftp://ftp.nic.merit.edu/nsfnet/statistics

Note : Results are one-way delays in milliseconds using 100 byte packets. For each cell, first number shows median, second number shows changes in median from previous reporting period (Dec 1992 and March 1994 for (a) and (b) respectively). Results are shown for changes > 1 ms.
Note : The numbers at the top row and first column represent the following nodes :

128 Palo Alto	129 Urbana-Champaign	130 Chicago	131 Ann Arbor	132 Pittsburgh
133 Ithaca	134 Boston	135 San Diego	136 College Park	137 Princeton
138 Georgia Tech	139 Houston	140 Lincoln	141 Boulder	142 Salt Lake City
143 Seatle	144 FIX-West NASA Ames	145 FIX-East College Park		145 DARPA

GVU's Center Third WWW User Survey data

• A snap shot of the Web population
• People spend a lot of time on the Web
  • 41% spend 6 - 10 hours/week
  • 72% use their browser at least once a day
• Most regular activities :
  • Replace FTP, Gopher, etc
  • Finding reference information
  • Reading news
  • Reading product information
• Most like pages with graphics (46.06%)

• Most servers connections upgraded from 1 Mb/s or below to 10 Mb/s
• Most users connections are 14.4 Kb/s

Project statistics

• Multimedia download time and realtime interactivities are still within acceptable range for local and international users
• No user support at the user end for problems with helper applications

What we are going to do next

• Control network traffic : network design, content design, etc
• Increase bandwidth