Evaluation of Multiplexing and Buffer Policies Influence on VoIP Conversation Quality
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Transcript of Evaluation of Multiplexing and Buffer Policies Influence on VoIP Conversation Quality
Presentación
Jose Saldana
Jenifer Murillo
Julián Fernández Navajas
José Ruiz Mas
Eduardo Viruete Navarro
José I. Aznar
O M U N I C A C I O N E S
TRUPO DE
CECNOLOGÍAS
GDE LAS
CPS - University of Zaragoza, Spain
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
Index
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
Index
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
4
Introduction
The use of Internet for multimedia transmission is growing as bandwidth increases.
Services with hard real-time
requirements:
- VoIP: Voice over IP
- Videoconferencing
- Online Gaming
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Introduction
- The use of best-effort networks for these services is a problem for the experienced quality
- Used protocols:
- Signaling: SIP, H.323
- Media transport: RTP, simple UDP
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Introduction
Real-time requirements force us to divide the information into small pieces, and send it using a small time period, and small packets.
This implies an overhead, as every packet needs the IP, UDP and maybe RTP headers
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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RTP packet
RTP packets’ overhead
VoIP packet with 2 G.729a samples
Efficiency: 33% for IPv4
IP header UDP header RTP header Sample Sample
8 bytes20 bytes 12 bytes 10 bytes 10 bytes
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Scenarios where many multimedia flows share a path. Does it represent an advantage?
Office
Data centre
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Scenarios where many multimedia flows share a path. Does it represent an advantage?
Internet café
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Two possible improvements Improvement 1: RTP compression schemes:
- CRTP: RFC 2508, February 1999
- ECRTP: RFC 3545, July 2003: Enhanced CRTP for scenarios with packet loss, packet reordering and long delays.
- ROHCv2: RFC 5225, April 2008
They use the repeatability of IP/UDP/RTP headers to compress them.
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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RTP compression - The two extremes share a context.
- Every packet carries a CID
- Some fields are avoided, other are compressed (delta compression, etc.) or inferred from lower layers
Problems:
- Only hop-by-hop usage
- Synchronization of the context
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Increasing the number of samples
Improvement 2: More samples in a single packet. If they belong to the same flow:
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Increasing the number of samples
If different flows share the same path (voice trunking) the packet frequency can be the same. Added delays?
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Increasing the number of samples
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Increasing the number of samples
Maximum added delay: Packet period. Independent of the number of flows
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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IP header UDP header RTP header
IP header L2TP
Sample Sample IP header UDP header RTP header Sample Sample IP header UDP header RTP header Sample Sample
RH Sample Sample RH Sample Sample RH Sample Sample
PPP PPPMux PPPMux PPPMux
RTP multiplexing
Combines header compression and multiplexing a number of flows. Advantages:
- Reducing overhead, bandwidth saving
- Reducing packets per second
Real scale
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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RTP multiplexing
Disadvantages:
- New added delays
- Processing charge
Increasing packet size: Good or bad?
Real scale
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
IP header UDP header RTP header
IP header L2TP
Sample Sample IP header UDP header RTP header Sample Sample IP header UDP header RTP header Sample Sample
RH Sample Sample RH Sample Sample RH Sample Sample
PPP PPPMux PPPMux PPPMux
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Influence of the router
- The amount and size distribution of background traffic will affect the real-time traffic.
- Packet loss can be modified with the change of packet size, depending on the policy of the router’s buffer.
- Routers have a pps limitation.
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Motivation of this work
- Study the influence of buffer policies and multiplexing schemes on the perceived quality, for real-time services.
- Service used: VoIP. Representative.
- Real-time requirements
- Wide-deployed service
- Existence of scenarios where many flows share the same path
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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R-factor - Defined by ITU G.107 (E-Model)
- Ranges from 0 (bad quality) to 100 (good)
- Acceptable for R > 70
- Dependence on delay and packet loss
- Widely accepted quality estimator for VoIP services
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
INTRODUCTION RTP COMPRESSION RTP MULTIPLEXING ROUTER R-FACTOR
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
Index
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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RTP multiplexing proposals - Different proposals. We will consider:
- TCRTP (RFC 4170): Tunneling Multiplexed Compressed RTP.
- Sze: «A Multiplexing Scheme for H.323 VoIP Applications», IEEE J. Selected Areas Comm., Sep 2002.
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
MULTIPLEXING PROPOSALS MULTIPLEXING USES BUFFER POLICIES
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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TCRTP - It does not define a new protocol.
Combines some of them.
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
PPP
PPP Mux
ECRTP
samples
IP
UDP
RTP...
ECRTP
samples
L2TP
IP
MULTIPLEXING PROPOSALS MULTIPLEXING USES BUFFER POLICIES
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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- Different Reduced Header sizes (ECRTP)
- The use of the L2TP tunnel makes it possible to use ECRTP end-to-end
Example: 3 RTP packets with 2 samples per packet:
IP header L2TP RH Sample Sample RH Sample Sample RH Sample Sample
PPP PPPMux PPPMux PPPMux
TCRTP
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
MULTIPLEXING PROPOSALS MULTIPLEXING USES BUFFER POLICIES
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Sze - Includes many RTP packets into a UDP one
- Different Reduced Header sizes
- Need of some tables at the origin and destination. Non standard
Exampe: 3 RTP packets with 2 samples per packet:
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
MULTIPLEXING PROPOSALS MULTIPLEXING USES BUFFER POLICIES
IP header UDP headerR
HSample Sample
R
HSample Sample RH Sample Sample
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Packet size comparative 3 multiplexed packets
5 multiplexed packets
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
MULTIPLEXING PROPOSALS MULTIPLEXING USES BUFFER POLICIES
Real scale
RTP
TCRTP
Sze
IP header UDP header RTP header
IP header L2TP
IP header UDP header
Sample Sample IP header UDP header RTP header Sample Sample IP header UDP header RTP header Sample Sample
RH Sample Sample RH Sample Sample RH Sample Sample
R
HSample Sample
R
HSample Sample RH Sample Sample
PPP PPPMux PPPMux PPPMux
IP header UDP header RTP header
IP header L2TP
IP header UDP header
Sample Sample IP header UDP header RTP header Sample Sample IP header UDP header RTP header Sample Sample IP header UDP header RTP header Sample Sample IP header UDP header RTP header Sample Sample
RH Sample Sample RH Sample Sample RH Sample Sample RH Sample Sample RH Sample Sample
R
HSample Sample
R
HSample Sample
R
HSample Sample
R
HSample Sample RH Sample Sample
PPP PPPMux PPPMux PPPMux PPPMuxPPPMux
RTP
TCRTP
Sze
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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RTP multiplexing uses - Bandwidth relationship
- Packets per second: reduced by k
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
MULTIPLEXING PROPOSALS MULTIPLEXING USES BUFFER POLICIES
0,3
0,4
0,5
0,6
0,7
0,8
0,9
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
X
k
Bandwidth Saving X for p = 0.95 S=10 bytes
Xrh S=10
S=20 bytes
Xrh=20
S=30 bytes
Xrh S=30
BW compressed/BW native
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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RTP multiplexing uses - Packet size increase
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
MULTIPLEXING PROPOSALS MULTIPLEXING USES BUFFER POLICIES
0
100
200
300
400
500
600
700
800
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
byte
s
k
Packet sizeRTP S=10 bytes
RTP S=20 bytes
RTP S=30 bytes
TCRTP S=10 bytes
TCRTP S=20 bytes
TCRTP S=30bytes
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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- «Rule of the thumb»: Bandwidth-delay product.
- «Stanford model»: Division by sqrt(N) (N:number of TCP flows).
- Other proposal: time-limited buffer. Interesting for this work. Limits OWD. But penalizes big packets
Buffer size and buffer policies
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
MULTIPLEXING PROPOSALS MULTIPLEXING USES BUFFER POLICIES
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Buffer size and buffer policies - Multiplexing tradeoffs
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
MULTIPLEXING PROPOSALS MULTIPLEXING USES BUFFER POLICIES
Bandwidth saving
Multiplexing
Bigger packet size
Packet loss increase
Packet loss reduction
Buffer policy
Added delays R-factor
R-factor
R-factor
Background traffic
Reduced pps Packet loss reduction
R-factor
Router limitation
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Buffer size and buffer policies - We will compare
- Dedicated buffer: Only VoIP
- High-capacity buffer
- Time-limited buffer
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
MULTIPLEXING PROPOSALS MULTIPLEXING USES BUFFER POLICIES
IP network
MUX DEMUX .
.
.
.
.
.
RTP RTP multiplexing RTP
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
Index
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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General Scheme - Use of a testbed
- Generator: D-ITG: Statistics of packet size and inter packet delay.
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
GENERAL SCHEME TRAFFIC GENERATION SYSTEM DELAYS
Traffic
Generation
RouterTraffic
Capture
Real Traffic in a testbed
Network
delays
+
Dejitter
buffer
Offline post-processing
Traffic
Trace
Final
Results
VoIP
Background
Buffer
policies
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Traffic generation - Background traffic
- 50% 40 bytes
- 10% 576 bytes
- 40% 1500 bytes
- Only UDP, in order to avoid flow control: always the same background traffic.
- Different rates to saturate the access router
- Network does not loose packets
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
GENERAL SCHEME TRAFFIC GENERATION SYSTEM DELAYS
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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Traffic generation - Multiplexed VoIP traffic
- Three header sizes:
- COMPRESSED_RTP 97.3%
- COMPRESSED_UDP 2.6%
- FULL_HEADER 0.0033% (negligible)
- Packet size: Binomial k, p=0.973
- Used for TCRTP and Sze.
- 400 seconds of traffic. First and last 20 are discarded
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
GENERAL SCHEME TRAFFIC GENERATION SYSTEM DELAYS
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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System delays - Packetization delay: G.729a.
- 15, 25 or 35 ms
- Retention time at the mux: Packet period
- Process: 5ms
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
IP network
MUX DEMUX
Tprocess Tqueue Tnetwork Tprocess TdejitterTretentionTpacketization
.
.
.
.
.
.
RTP RTP multiplexing RTP
GENERAL SCHEME TRAFFIC GENERATION SYSTEM DELAYS
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
37
System delays - Packetization delay: G.729a.
- 15, 25 or 35 ms
- Retention time at the mux: Packet period
- Process: 5ms
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
IP network
MUX DEMUX
Tprocess Tqueue Tnetwork Tprocess TdejitterTretentionTpacketization
.
.
.
.
.
.
RTP RTP multiplexing RTP
GENERAL SCHEME TRAFFIC GENERATION SYSTEM DELAYS
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
38
System delays - Packetization delay: G.729a.
- 15, 25 or 35 ms
- Retention time at the mux: Packet period
- Process: 5ms
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
IP network
MUX DEMUX
Tprocess Tqueue Tnetwork Tprocess TdejitterTretentionTpacketization
.
.
.
.
.
.
RTP RTP multiplexing RTP
GENERAL SCHEME TRAFFIC GENERATION SYSTEM DELAYS
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
39
System delays (2) - Queuing delay
- Network delay
- Fixed: 20ms
- Lognormal: avg 20ms. Variance 5
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
IP network
MUX DEMUX
Tprocess Tqueue Tnetwork Tprocess TdejitterTretentionTpacketization
.
.
.
.
.
.
RTP RTP multiplexing RTP
GENERAL SCHEME TRAFFIC GENERATION SYSTEM DELAYS
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
40
System delays (2) - Queuing delay
- Network delay
- Fixed: 20ms
- Lognormal: avg 20ms. Variance 5
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
IP network
MUX DEMUX
Tprocess Tqueue Tnetwork Tprocess TdejitterTretentionTpacketization
.
.
.
.
.
.
RTP RTP multiplexing RTP
GENERAL SCHEME TRAFFIC GENERATION SYSTEM DELAYS
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
41
System delays (3) - De-jitter buffer: adds delays and packet
losses:
- loss de-jitter buffer ~ P { l > bg}
- delay de-jitter buffer : number of samples
- Buffer size: maximize R-factor. Static.
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
IP network
MUX DEMUX
Tprocess Tqueue Tnetwork Tprocess TdejitterTretentionTpacketization
.
.
.
.
.
.
RTP RTP multiplexing RTP
GENERAL SCHEME TRAFFIC GENERATION SYSTEM DELAYS
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
Index
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
43
Dedicated buffer - 200 kbps only for VoIP
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
76
77
78
79
80
81
82
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
R-f
ac
tor
Number of multiplexed calls k
R-factor
RTP
TCRTP
Sze
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
44
Dedicated buffer - 200 kbps only for VoIP
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
76
77
78
79
80
81
82
5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
R-f
ac
tor
Number of multiplexed calls k
R-factor
RTP
TCRTP
Sze
Effect of bandwidth saving
Effect of added delays
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
45
High capacity buffer - 1Mbps shared. 5 flows
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
60
65
70
75
80
85
400 450 500 550 600 650 700 750 800 850 900 950 1000
R-f
acto
r
background traffic (kbps)
R factor 1 RTP
5 RTP
5 TCRTP
5 Sze
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
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High capacity buffer - 1Mbps shared. 5 flows
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
60
65
70
75
80
85
400 450 500 550 600 650 700 750 800 850 900 950 1000
R-f
acto
r
background traffic (kbps)
R factor 1 RTP
5 RTP
5 TCRTP
5 Sze
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
Step-like graphs. When the bandwidth is not enough, the quality falls
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
47
High capacity buffer - 1Mbps shared. 10 flows
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
60
65
70
75
80
85
400 450 500 550 600 650 700 750 800 850 900 950 1000
R-f
acto
r
background traffic (kbps)
R-factor 1 RTP
10 RTP
10 TCRTP
10 Sze
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
48
High capacity buffer - 1Mbps shared. 15 flows
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
60
65
70
75
80
85
400 450 500 550 600 650 700 750 800 850 900 950 1000
R
background traffic (kbps)
R factor 1 RTP
15 RTP
15 TCRTP
15 Sze
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
49
High capacity buffer - 1Mbps shared. 20 flows
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
60
65
70
75
80
85
400 450 500 550 600 650 700 750 800 850 900 950 1000
R
background traffic (kbps)
R factor 1 RTP20 RTP20 TCRTP20 Sze
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
The bigger the number of flows, the bigger the bandwidth saving
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
50
Time-limited buffer - 1Mbps shared. 5 flows
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
66
68
70
72
74
76
78
80
82
400 450 500 550 600 650 700 750 800 850 900 950 1000
R-f
acto
r
background traffic (kbps)
R-factor1 RTP
5 RTP
5 TCRTP
5 Sze
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
51
Time-limited buffer - 1Mbps shared. 5 flows
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
66
68
70
72
74
76
78
80
82
400 450 500 550 600 650 700 750 800 850 900 950 1000
R-f
acto
r
background traffic (kbps)
R-factor1 RTP
5 RTP
5 TCRTP
5 Sze
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
Time-limited buffer: slope instead of step-like
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
52
Time-limited buffer - 1Mbps shared. 5 flows
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
66
68
70
72
74
76
78
80
82
400 450 500 550 600 650 700 750 800 850 900 950 1000
R-f
acto
r
background traffic (kbps)
R-factor1 RTP
5 RTP
5 TCRTP
5 Sze
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
Native RTP behaves better than multiplexing schemes
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
53
Time-limited buffer - 1Mbps shared. 10 flows
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
66
68
70
72
74
76
78
80
82
400 450 500 550 600 650 700 750 800 850 900 950 1000
R-f
acto
r
background traffic (kbps)
R-factor1 RTP
10 RTP
10 TCRTP
10 Sze
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
54
Time-limited buffer - 1Mbps shared. 10 flows
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
66
68
70
72
74
76
78
80
82
400 450 500 550 600 650 700 750 800 850 900 950 1000
R-f
acto
r
background traffic (kbps)
R-factor1 RTP
10 RTP
10 TCRTP
10 Sze
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
Gaining zone
0.5% worse
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
55
Time-limited buffer
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
0
5
10
15
20
400 450 500 550 600 650 700 750 800 850 900 950 1000
Pac
ket
Loss
(%
)
background traffic (kbps)
Background Traffic Packet Loss 1 RTP
10 RTP
10 TCRTP
10 Sze
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
The bigger the bandwidth saving, the smaller the packet loss
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
56
Time-limited buffer - 1Mbps shared. 15 flows
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
60
62
64
66
68
70
72
74
76
78
80
82
400 450 500 550 600 650 700 750 800 850 900 950 1000
R-f
acto
r
background traffic (kbps)
R-factor
1 RTP
15 RTP
15 TCRTP
15 Sze
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
57
Time-limited buffer - 1Mbps shared. 20 flows
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
60
62
64
66
68
70
72
74
76
78
80
82
400 450 500 550 600 650 700 750 800 850 900 950 1000
R-f
acto
r
background traffic (kbps)
R-factor
1 RTP
20 RTP
20 TCRTP
20 Sze
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
58
Time-limited buffer
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
-10
-5
0
5
10
15
20
25
400 450 500 550 600 650 700 750 800 850 900 950 1000
% R
-fac
tor
imp
rove
me
nt
background traffic (kbps)
% R-factor improvement5 TCRTP5 Sze10 TCRTP10 Sze15 TCRTP15 Sze20 TCRTP20 Sze
DEDICATED BUFFER HIGH CAPACITY BUFFER TIME-LIMITED BUFFER
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
Index
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
60
Conclusions - Comparison of multiplexing schemes
- Service used: VoIP
- New delays added: small. The bandwidth saving is significant
- R-factor
- improvement up to 20%
- impairment 1%
- Packet size is important, depending on buffer policies
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
61
Conclusions - Is it better to use only one tunnel or to
group calls into a number of tunnels?
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
50
55
60
65
70
75
80
85
400 450 500 550 600 650 700 750 800 850 900 950 1000
R
background traffic (kbps)
R factor
20 RTP
20 TCRTP
2x10 TCRTP
CCNC January 9-11, 2011. Las Vegas Evaluation of Multiplexing and Buffer Policies Influence on VoIP
62
Conclusions - Is it better to use only one tunnel or to
group calls into a number of tunnels?
INTRODUCTION RELATED WORKS TEST METHODOLOGY RESULTS CONCLUSIONS
50
55
60
65
70
75
80
85
400 450 500 550 600 650 700 750 800 850 900 950 1000
R
background traffic (kbps)
R factor
20 RTP
20 TCRTP
2x10 TCRTP
Presentación
Jose Saldana
Jenifer Murillo
Julián Fernández Navajas
José Ruiz Mas
Eduardo Viruete Navarro
José I. Aznar
O M U N I C A C I O N E S
TRUPO DE
CECNOLOGÍAS
GDE LAS
CPS - University of Zaragoza, Spain