A Comparative Study of VoIP
Standards with Asterisk
Fourth International Conference onDigital Telecommunications, 2009. ICDT '09.
20-25 July 2009
Advisor : Lian-Jou Tsai
Student : PEI-SIOU HUANG
Date : 2013/3/07
最近研究方向
 Asterisk
 VoIP Standards
Outline
 Abstract
 INTRODUCTION
 VOIP PROTOCOLS UNDER ANALYSIS
 DESCRIPTION OF THE TESTBED
 ANALYSIS OF THE EXPERIMENTAL RESULTS
 CONCLUSIONS
Abstract
 Since the apparition of Voice over IP (VoIP),
many standards (mainly signaling protocols
and codecs) have arisen with the aim of
enabling voice calls through data networks.
INTRODUCTION
 Voice over Internet Protocol (VoIP) has
become a very popular technology.
 extend these analysis to compare the
performance of different signaling protocols
and codecs for voice calls in an actual VoIP
testbed based on Asterisk
VOIP PROTOCOLS UNDER
ANALYSIS(1)
Protocols :H.323, SIP, IAX
H.323 and SIP for signaling and RTP for the transport.
IAX is a new concept in VoIP as it combines both functions in the
same protocol. (signaling and multimedia)
VOIP PROTOCOLS UNDER
ANALYSIS(2)
DESCRIPTION OF THE TESTBED(1)
Figure 1. Test bed under study
DESCRIPTION OF THE TESTBED(2)
Figure 2. Connection diagram
DESCRIPTION OF THE TESTBED(3)
ANALYSIS OF THE
EXPERIMENTAL RESULTS(1)
Processor
As it was previously remarked, when no transcoding is
performed, the main processor load is the routing of the
calls.
ANALYSIS OF THE
EXPERIMENTAL RESULTS(2)
Memory Utilization
All results are in the range of 33 MB to 42 MB
ANALYSIS OF THE
EXPERIMENTAL RESULTS(3)
Bandwidth Consumption
one for the reception traffic and one for the
transmission traffic. Both of them should be
equal
ANALYSIS OF THE
EXPERIMENTAL RESULTS(4)
show the benefits of trunking
ANALYSIS OF THE
EXPERIMENTAL RESULTS(5)
CONCLUSIONS(1)
CONCLUSIONS(2)
For g.711 (A law), g.726 and gsm: 54 bytes/20 ms = 2700 bytes/s =
21,6 kbps.
For lpc10 will be: 54 bytes/22,5 ms = 2400 bytes/s = 19,2 kbps.
For g.711: 54 bytes of headers + 160 of data bytes
=214bytes/frame (25 % corresponding to headers).
For g.726: 54 bytes headers + 80 data bytes = 134bytes/frame (40
% corresponding to headers).
For gsm: 54 bytes headers + 33 data bytes = 87bytes/frame (62 %
corresponding to headers).
For lpc10: 54 bytes headers + 7 data bytes = 61bytes/frame (88 %
corresponding to headers).
CONCLUSIONS(3)
46bytes/20 ms=2300 bytes/s = 18,4 kbps, While for lpc10 will be:
46 bytes/22,5 ms=2044 bytes/s=16,3 kbps.
For g.711 (A law): 46 bytes headers + 160 databytes=206
bytes/frame (22 % corresponding toheaders).
For g.726: 46 bytes headers + 80 data bytes = 126
bytes/frame (36 % corresponding to headers).
For gsm: 46 bytes headers + 33 data bytes = 79
bytes/frame (58 % corresponding to headers).
For lpc10: 46 bytes headers + 7 data bytes = 53
bytes/frame (87 % corresponding to headers).
CONCLUSIONS(4)
For g.711 (A law): 188 bytes of IAX headers + 168bytes (4
packets) of UDP/IP/Ethernet headers +
4800 data bytes (30 calls x 160 bytes/frame) = 5156bytes (7 %
corresponding to headers).
g.726: 188 bytes IAX headers + 84 bytes (2 packets)headers of
UDP/IP/Ethernet headers + 2400 data bytes (30 calls x 80
bytes/frame)= 2672 bytes (10 %corresponding to headers).
gsm: 188 bytes IAX headers + 42 bytes (1 packet) of headers of
UDP/IP/Ethernet headers + 990 data bytes (30 calls x 33
bytes/frame)= 1220 bytes (19 % corresponding to headers).
lpc10: 188 bytes IAX headers + 42 bytes (1 packet) of headers of
UDP/IP/Ethernet headers + 210 data bytes (30 calls x 7
bytes/frame)= 440 bytes (52 % corresponding to headers).
CONCLUSIONS(5)
Different VoIP codecs and protocols have been compared
obtaining empirical results about processor and memory
utilization and bandwidth consumption.
Results show the clear benefits of employing call trunking
(under IAX) as it reduces the overhead introduced by protocol
headers, especially when a high number of simultaneous calls
are multiplexed.
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Thank You For Your Attention!