Limiting Performance Evaluation of Client/Server Local Area Networks, Based on Transfer Time under Traffic Congestion

1
Title
Limiting Performance Evaluation of Client/Server
Local Area Networks, Based on Transfer Time under
Traffic Congestion
Satoru Fujimoto, Kazue Tsujimura, Satoshi
Hayashi, Jian Wang, and Yutaka Katsuyama
Graduate School of Engineering, Osaka Prefecture
University
2
Background
- The internet traffic increases rapidly year by
year. - The network should be replaced with
faster products. - What is the performance?
Clients
Congestion? Replacing 10 with 100 Base?
Intranet System
Server
Hub
We want to estimate the performance simply.
How can we obtain better performance by the
replacement?
3
Objectives
Many kinds of analysis have been reported to
estimate LAN performance.
However, ...
Many of them contain probability of communication
occurrence of the clients Poisson processes
As a result, ...
Analyzed results are complicated and parameter
values should be input to obtain the
performance. We need simpler formulae in a
limiting conditions easy to estimate for
non-professional users.
4
Whats presented?
We present
(1). Limiting Performance of a LAN
-Transfer Time Analysis under a Simultaneous
Transfer Model Formulae to Give the Limiting
Performance -Measured Calculated
Results (2). Performance Improvement
Evaluation When replacing 10Base with 100Base
Products -Measured Calculated Results
5
LAN Configuration to be Evaluated
CSMA/CD LAN
CL1
CL2
Hub
Server
CLn
Congestion
10Base-T 100Base-T
6
Packet Transfer Model for the Evaluation
7
Packet Flow to Server
1
x
x
x
x
x
x
x
2
x
x
x
x
x
x
x
n
x
x
x
x
x
x
x
Time
one packet transfer time
processing time between packets
8
Formulae
Formulae
LAN
10Base
100Base
1
n
8
?
?
10/100Base
9
n
?
one packet transfer time
processing time between packets
9
Transfer Time Measurement Tool
CL1
Controller
FTP Server
CLn
10
Transfer Time Measurement by the Tool
Measurement Program
Controller



?Start
?Start


?Search



Search Button
?Detect


?Client Ready
?Measurement Starts
?Condition Input

11
Measurement Result Display
12
Measured and Calculated Transfer Time -1
10 Base LAN
200
Measured
Calculated
Client Number
150
1
2
3
4
Transfer Time (s)
100
5
6
7
8
50
0
0
5
10
15
20
File Size F (MB)
13
Measured and Calculated Transfer Time -2
100Base LAN
16
Measured
Calculated
Client Number
12
1
2
3
4
Transfer Time (s)
5
6
8
7
4
0
0
5
10
15
20
File Size F (MB)
14
Obtained Parameter Values
LAN
t
(msec)
x
(msec)
u
10Base
1.207
-
0.575
-
100Base
-
0.134
-
0.028
1
n
8
1.240
-
-
0.023
?
?
10/100Base
9
n
-
0.134
-
0.028
?
14608bits/10Mbps1.2 ms (10Base) 0.12 ms
(100Base)
15
Throughput Improvement with Replacement
CL1
10Base Hub
CL2
Hub
Server
CLn
10/100Base Hub
Replace this with
or
100Base Hub
16
Throughput Improvement
10/100 Base Hub
10
8
Improvement
Measured
6
Calculated
Throughput (Mbps)
10Base
4
10/100Base
2
0
0
2
4
6
8
10
Client Number n
17
Throughput Improvement
100 Base Hub
100
100Base
Measured
80
10Base
60
Throughput(Mbps)
Improve- ment
40
Calculated
20
0
0
2
4
6
8
Client Number n
18
Conclusion
(1). Limiting performance of CSMA/CD LAN has
been evaluated theoretically and
experimentally. - Simultaneous Transfer Model -
Simple Useful Formulae - Good Agreement with
Measured Values (2). Performance improvement by
replacements has been evaluated quantitatively,
based on the limiting performance approach.
19
Obtained and Expected Parameter Values