Voice and Video over Ip

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Objectives
Use terminology specific to converged networks
Explain VoIP (voice over IP) services and their user interfaces Explain video-over-IP services and their user interfaces
Describe VoIP and video-over-IP signaling and transport protocols, including SIP, H.323, and RTP Understand QoS (quality of service) assurance methods critical to converged networks, including RSVP and DiffServ Terminology

IP Telephony
IP telephony (VoIP)
Any network carrying voice signals using TCP/IP
Public or private
Runs over any packet-switched network
VoATM (voice over ATM)
VoDSL (voice over DSL)
Data connection types carrying VoIP signals
T-carriers, ISDN, broadband cable, satellite connections, WiFi, WiMAX, cellular telephone networks IP Telephony
Internet telephony
VoIP relies on Internet
Advantage: breadth and low cost
Private lines can also carry VoIP calls
Effective and economical
Network congestion control capabilities
Better sound quality
Non-Data Applications
Other non-data applications on converged networks
FoIP (Fax over IP)
IPTV (IP television)
Videoconferencing
Multiple participants communicate and collaborate via audiovisual means •Streaming video
Compressed video delivered in continuous stream
Hulu.com for free Internet TV shows
Webcasts
Streaming videos supplied via the Web
Terminology
Multicasting
One node transmits same content to every client in group Video over IP
IPTV, videoconferencing, streaming video, IP multicasting Unified communications (unified messaging) service
Several communication forms available from single user interface

VoIP (Voice over IP) Applications and Interfaces
VoIP (Voice over IP) Applications and Interfaces
Significant VoIP implementation reasons
Lower voice call costs (toll bypass)
New, enhanced features and applications
Centralize voice and data network management
Voice and data configurations
Traditional telephone (sends, receives analog signals)
Telephone specially designed for TCP/IP transmission
Computer with microphone, speaker, VoIP client software
Mixture
Analog Telephones
Using traditional telephone, digital VoIP connection
Must convert voice signals into bits
Analog-to-digital conversion
Codec
Method to accomplish analog signal compressing, encoding
ATA (analog telephone adapter)
Card within computer workstation, externally attached device Telephone line connects to RJ-11 adapter port
Converts analog voice signals to IP packets
VoIP-Enabled Router
Connect
Analog telephone line to VoIP-enabled device (switch, router, gateway) Convert
Analog voice signals into packets

Digital PBX (IP-PBX)
PBX (private branch exchange): telephone switch connecting calls within a private organization IP-PBX
Private switch
Accepts, interprets both analog and digital voice signals •Connects with traditional PSTN lines, data networks
Transmits, receives IP-based voice signals to and from other network connectivity devices •Packaged with sophisticated software

Analog PBX with Gateway
Traditional telephone connects to analog PBX
Then connects to voice-data gateway
Gateway connects traditional telephone circuits with TCP/IP network •Internet or private WAN
Gateway
Digitizes incoming analog voice signal
Compresses data
Assembles data into packets
Issues packets to packet-switched network
IP Telephones
IP telephones (IP phones)
Transmit, receive only digital signals
Voice immediately digitized, issued to network in packet form •Requires unique IP address
Looks like traditional touch-tone phone
Connects to RJ-45 wall jack
Connection may pass through connectivity device before reaching IP-PBX IP telephones: popular and unique features
Web browser screens
Connect to user’s PDA
Speech recognition capabilities
Busy line instant message option
Accept emergency messages
IP telephones: mobility
Move phone to new office; connect to wall...
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