This PowerPoint helps students to consider the concept of infinity.
AQM performance for VOIP
1. Performance Analysis of AQM
for VOIP Application
MakkawiAbdelsalmMohammed
Khair
Future university ,249915001523,
khairmakkawi@gmail.com
Dr. Mohammed Hussain
Supervisor
3. VOIP
•Voice Over Internet Protocol
•Is the technology that uses the Internet Protocol to
transmit voice conversation over a data network.
•The primary advantages of moving voice over a data
network are increased efficiency and decrease cost.
5. Enterprise: Private Branch Exchange (PBX)
7043
7040
7041
7042
External line
Telephone
switch
Private Branch
Exchange
212-8538080
Another
switch
Corporate/Campus
InternetCorporate/Campus LAN
Post-divestiture phenomenon...
6. Enterprise VoIP: Yesterday’s networks
Circuit Switched Networks (Voice)
Packet Switched Networks (IP)
PBX
PBX
CO
CO
CO
Router
Router
Router
Router
Router
Headquarters Branch Offices
7. Enterprise VoIP: Today’s networks
Toll by-pass
Circuit Switched Networks (Voice)
Packet Switched Networks (IP)
PBXPBX
CO
CO
CO
Router
Router
RouterRouter
Router
Headquarters Branch Offices
8. Enterprise VoIP: Tomorrow’s networks
Unified/Converged Networks
Unified Networks (Voice over IP)
Router
Router
Router
Router
Router
CO
CO
Legacy PSTN
Headquarters Branch Offices
9. Problems
The main problem of this work is that voice is highly sensitive for delay and packet
loss in network (Cisco Systems, 1992–2008).
It is crucial to have a proper QoS mechanism to guarantee minimum delay and
packet loss
Therefore, it is the purpose of this research to determine how does the AQM
mechanisms deal with the services such as VoIP. Furthermore, it will try to
investigate what are the most powerful mechanisms that can provide the best
results to meet the objective of the Quality of Services (QoS).
10. Objectives
It is the objective of this research to compare the performance of four mechanism of AQM in terms of packet
delay, packet loss, variation of delay and throughput.
Specifically it would like to achieve the following:
1. Determine the performance of RED (Random Early Detection) in terms of:
a) Packet delay
b) Packet loss
c) Variation of packet delay
d) Throughput
2. Determine the performance of ARED (Adaptive Random Early Detection) in terms of
a) Packet delay
b) Packet loss
c) Variation of packet delay
d) Throughput
11. Objectives
3. Determine the performance of GRED (Gentle Random Early Detection) in terms of
3. Packet delay
4. Packet loss
5. Variation of packet delay
6. Throughput
4. Determine the performance of WRED (Weighted Random Early Detection) in terms of
a)Packet delay
b)Packet loss
c)Variation of packet delay
d)Throughput
12. 12
Active Queue Management
Queue
Sink
Outbound LinkRouterInbound Link
Sink
ACK…
ACK…
Queue
Sink
Outbound LinkRouterInbound Link
Sink
ACK…
ACK…
Queue
Sink
Outbound LinkRouterInbound Link
Sink
ACK…
Drop!!!
Queue
Sink
Outbound LinkRouterInbound Link
Sink
Queue
Sink
Outbound LinkRouterInbound Link
Sink
AQM
Congestion
Congestion Notification…
ACK…
Queue
Sink
Outbound LinkRouterInbound Link
Sink
AQM
Advantages
• Reduce packet losses
(due to queue overflow)
• Reduce queuing delay
scr2
scr1
13. Let us See How This Mechanisms Works ….
RED (Random Early Detection)
31. First scenario parameters
• This scenario based on changing the number of users
while the other parameters remain constant
• The below table shows the simulation parameters that
used in this scenario
32. Simulation parameters
Number of User Variable from 5-300
Data forwarding rate (packets/second) 500000
Maximum queue size 100
Minimum threshold 10
Maximum threshold 20
Mark probability denominator 0.1
Simulation duration 1 hour
Encoder scheme G.711 (silence)
Voice frame per packet 5
40. Second scenario parameters
• This scenario based on changing the number of users
while the other parameters remain constant
• The below table shows the simulation parameters that used in this
scenario
41. Simulation parameters
Number of User 10 ,50,300
Data forwarding rate (packets/second) 500000
Maximum queue size Variable
200,300,500,1000
Minimum threshold 20
Maximum threshold 60
Mark probability denominator 0.1
Simulation duration 1 hour
Encoder scheme G.711 (silence)
Voice frame per packet 5
50. Conclusion
• This study evaluated the performance of VoIP over Ethernet WAN by applying AQM mechanism
using OPNET simulation tool.
• A comparison has been conducted between four of (AQM Active Queue Management) methods
RED, ARED, GRED and WRED This comparison aimed to identify which method offers more
satisfactory performance measures for application like VOIP.
• A decision which method offers more satisfactory performance measure results is only made
depending on varying the number of users and number of maximum queue size in the routers
• It has been found that the configuration of the RED algorithm and GRED is not axiomatic. They
must consider many situations such as network traffic, the traffic type, nature and duration of
possible bursts, delays in the network, etc.
• It has been seen that in general, the ARED and GRED algorithms performs better, achieving a
lower discard rate and lower overall delay. One problem that has been is the average queue size
parameter tends to oscillate, especially given configuration changes and wq the minimum
threshold, so care must be taken to configure.
51. Future work
• This study used the comparison according to one type of traffic, it recommend that to use some
other traffic such as Http or video to see how this mechanism will deal with the VoIP packets while
there is another types of packet.
• Other parameters could be considered such as different encoder scheme and number of voice
frame per packet.
