Embed Size (px)
DESCRIPTION
In the past five years, technologies have converged to such an extent that one can transmit voice, fax and video over the same internet protocol network that one uses for data. This workshop examines Voice over IP (VoIP) technologies and provides you with the skills to competently implement a VoIP network for your organisation. Numerous case studies and exercises throughout the course ensure that you get a good grasp on the technologies used. Solid practical advice is given on application, implementation and most importantly troubleshooting these systems. MORE INFORMATION: http://www.idc-online.com/content/practical-fundamentals-voice-over-ip-voip-engineers-and-technicians-3
Citation preview
Technology Training that worksTechnology Training that Workswww.idc-online.com/slideshare
Practical Fundamentals of Voice over Internet Protocol (VOIP) for Engineers and Technicians
Technology Training that worksTechnology Training that Workswww.idc-online.com/slideshare
Definition“ Voice Over IP (VOIP) is a converged network application that
allows voice, data, video and fax to be transported over existing IP data networks instead of conventional Public Switched
Telephone Network (PSTN).”
Technology Training that worksTechnology Training that Workswww.idc-online.com/slideshare
Voice
Data
Packet Voice
IP Data
IP Data
IP Telephony Circuit Switched Networks (TDM)
IP+ATM
IP
Packet Switched (Converged) Networks
Networks
Technology Training that worksTechnology Training that Workswww.idc-online.com/slideshare
VOIP
• Is a Layer 3 network protocol
• Uses Layer 2 point-to-point or link layer protocols (such as PPP,Frame relay or ATM for its transport)
• Digital Signal Processors (DSPs) segment the voice signal into frames and store them in voice packets.
Technology Training that worksTechnology Training that Workswww.idc-online.com/slideshare
VoiceSource
VoiceDestination
ADC DAC
ManagedIP CLOUD
AnalogueSignal
AnalogueSignal
DigitalSignal
DigitalSignal
VOIP BASIC DIAGRAM
Technology Training that worksTechnology Training that Workswww.idc-online.com/slideshare
VOIP
• Voice packets are transported via IP in compliance with voice communication protocols or standards– Such as H.323 ,Media Gateway Control
Protocol(MGCP) or Session Initiation Protocol (SIP)
Technology Training that worksTechnology Training that Workswww.idc-online.com/slideshare
Relationship of OSI and VOIP
OSI Layer Number
OSI layer Name
VOIP Protocols and Functions
7 Application Net Meeting
6 Presentation CODECS
5 Session H.323/MGCP/SIP
4 Transport RTP/TCP/UDP
3 Network IP
2 Data Link Frame Relay, ATM, Ethernet, PPP
Technology Training that worksTechnology Training that Workswww.idc-online.com/slideshare
IP is an attractive choice for voice transport because:
• Lower Equipment Cost – – IP based switch architecture is an open and distributed
architecture– Modular in concept
• Integration of Voice and Data application –– IP offers a converged and unified platform for transport
of data as well as voice
IP in VOIP
Technology Training that worksTechnology Training that Workswww.idc-online.com/slideshare
• Optimum Bandwidth Utilization – – Many bandwidth efficient coding algorithms have been
developed which are bandwidth efficient.
• Universal Acceptance and Availability of IP as a networking protocol
IP in VOIP
Technology Training that worksTechnology Training that Workswww.idc-online.com/slideshare
The problems in implementing VOIP are – • Speech Quality –
– IP basically designed for transporting data traffic
– Data traffic is asynchronous can tolerate delay
– Any appreciable delay in receipt of voice packet badly impairs quality of speech.
• Delay – – Voice does not tolerate delay
– ITU-T recommendation G.114 states that the round trip delay should be less than 300 ms for telephony applications
Problems in VOIP
Technology Training that worksTechnology Training that Workswww.idc-online.com/slideshare
• Jitter-Jitter is variation in delay – is caused in IP networks in two ways:
– Packets take different routes from source to destination and experience different delays
– Different packets experience different queuing time (due to sharing of available resources by different users)
Problems in VOIP
Technology Training that worksTechnology Training that Workswww.idc-online.com/slideshare
Packet loss –
• VOIP is based on packet switched network architecture – Voice is first digitized, packetized and then transported
in the form of packets
• If packets are lost in transit – Any retransmission will introduce delay – Voice quality impaired
Problems in VOIP
Technology Training that worksTechnology Training that Workswww.idc-online.com/slideshare
• Power Over Ethernet – – Traditional PSTN Telephones are DC powered on the
same conductors– For VOIP on LAN environment
• 802.3af compliant powered Ethernet Switches
• Picker
• Two Methods are –– (Injector) + (POE compatible Device)– (Injector) + (non-POE compatible Device)+(Picker)
Problems in VOIP
Technology Training that worksTechnology Training that Workswww.idc-online.com/slideshare
DO YOU WANT TO KNOW MORE?
If you are interested in further training or information, please visit:
http://idc-online.com/slideshare
