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IEX8175 RF Electronics. Avo Ots telekommunikatsiooni õppetool, TTÜ raadio- ja sidetehnika inst. [email protected]. Evolution. “how can I make it stop ringing?”. long-distance calling, ca. 1930. “does it do call transfer?”. going beyond the black phone. “amazing – the phone rings”. - PowerPoint PPT Presentation
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IEX8175 RF Electronics
Avo Otstelekommunikatsiooni õppetool,
TTÜ raadio- ja sidetehnika [email protected]
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Evolution
“amazing – thephone rings”
“does it docall transfer?”
“how can I make itstop ringing?”
1996-2000 2000-2003 2004-
catching upwith the digital PBX
long-distance calling,ca. 1930 going beyond
the black phone
Open Telephony
TDM/TDM/Circuit SwitchCircuit Switch
Digital Trunk Digital Trunk SubsystemSubsystem
Digital Trunk Digital Trunk SubsystemSubsystem
Line Line ConcentrationConcentration
Line Line ConcentrationConcentration
AdministrationAdministrationMaintenanceMaintenance
BillingBilling
AdministrationAdministrationMaintenanceMaintenance
BillingBilling
Call ControlCall ControlConnection ControlConnection Control
FeaturesFeatures
Call ControlCall ControlConnection ControlConnection Control
FeaturesFeatures
Common ChannelCommon ChannelSignaling ComplexSignaling ComplexCommon ChannelCommon ChannelSignaling ComplexSignaling Complex
Sw
itch
ing
Net
wo
rk
Standards-Based Standards-Based Packet Infrastructure LayerPacket Infrastructure Layer
(IP, ATM)(IP, ATM)
Standards-Based Standards-Based Packet Infrastructure LayerPacket Infrastructure Layer
(IP, ATM)(IP, ATM)
Open Call Control LayerOpen Call Control Layer(SIP, H.323, MGCP, etc.)(SIP, H.323, MGCP, etc.)
Open Call Control LayerOpen Call Control Layer(SIP, H.323, MGCP, etc.)(SIP, H.323, MGCP, etc.)
Open Service Open Service Application LayerApplication Layer
(JAIN, AIN, TAPI,(JAIN, AIN, TAPI,JTAPI, XML etc.)JTAPI, XML etc.)
Open Service Open Service Application LayerApplication Layer
(JAIN, AIN, TAPI,(JAIN, AIN, TAPI,JTAPI, XML etc.)JTAPI, XML etc.)
Open/Standard Interface
Open/Standard Interface
Brian Gracely, Cisco, 2001
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Channel Sharing
Channel Sharing Techniques
Static Channelization
Dynamic Medium Access Control
Scheduling
Random Access
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VoIP Codecs
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Voice Packet• Codec G.729A (ITU – T))
20 ms, => Payload 20 octets
Ethernet+FCS+Preamble: 26 bytes802.1q VLAN Tagging 4 bytesIP: 20 bytesUDP: 8 bytes RTP: 12 bytes
Voice Payload: 20 bytes----------90 bytes
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Overhead/payload
CodecType
Sample Size[ms]
Payload[octets]
Ethernet Packet
Size[octets]
Ethernet Load w/o Preamble
[kBit/s]
Overhead / Payload
ratio
G.711 30 240 310 82,7 24%G.711 60 480 550 73,3 12%
G.729A 20 20 90 36,0 290%G.729A 40 40 110 22,0 145%G.729A 60 60 130 17,3 97%
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Q o S
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Linkshttp://www.ietf.org/rfc/rfc0791.txt?number=791
http://www.ietf.org/rfc/rfc0793.txt?number=793
http://www.packetizer.com/
http://en.wikipedia.org/wiki/VoIP
