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Voip Voip Presentation Transcript

  • VoIP(Voice over Internet Protocol) Harry Sunarsa
  • Today we will deal with:• What is VoIP?• Ways of using VoIP?• Advantages & disadvantages?2/7/2013 HS 2
  • What is VoIP?VoIP allows you to maketelephone callsusing a computer network, overa data network like the Internet 2/7/2013 HS 3
  • How VoIP Works1. The voice is converted from an analog to a digital signal.2. The digital signal is broken up into packets.3. The packets are sent to the destination via Internet Protocol (IP).4. The packets are reassembled into a digital signal at the destination.5. The digital signal is converted to an analog signal and played back through the receiver.2/7/2013 HS 4
  • VoIP - Basics Application Server Signaling Path  Peer-to-peer Call  Or client/server VoIP Endpoint Server  SIP, H.323, or H.248 (terminal or gateway)  …/UDP/IP or TCP/IP IPAnalog AnalogVoice Voice Bearer Path Control Path  IP-end to IP-end  Statistics on performance of  Encoded voice bearer “channel”  Packetized  RTP Control Protocol (RTCP)  Real Time Protocol (RTP)  RTCP/UDP/IP  RTP/UDP/IP
  • VoIP Network Application Application Server Server Call Server Call VoIP Server Border Network #2 Gateway IP VoIP PBX Network #1 Access TrunkBusiness Border Gateway Gateway PSTN/ Access ISDN Gateway GW Home Home Home Home
  • Scenario 1: PC to PC  Need a PC with sound card  IP Telephony software(softphone): Skype, Gtalk, YMessenger , …  Video optional2/7/2013 HS 7
  • Scenario 2: PC to Phone Need a gateway that connects IP network to phone network2/7/2013 HS 8
  • Scenario 3: Phone to Phone  Need more gateways that connect IP network to phone networks  The IP network could be dedicated intra-net or the Internet.  The phone networks could be intra-company PBXs or the carrier switches2/7/2013 HS 9
  • Advantages & Disadvantages Advantages: • Low cost - Leads to greater financial savings • Portability – Not distance or location dependent. • Features: – 3-way calling, call forwarding, callback services and caller ID are usually standard features (free) – managing address books, video Conference, message or data file exchange2/7/2013 HS 10
  • Advantages & DisadvantagesDisadvantages:• No service during a power outage• Quality and Reliability – Depends on the internet stability• Security – identity and service theft, viruses and malware, denial of service, and spamming2/7/2013 HS 11
  • Conclusion• Overall, VoIP is a great low cost alternative for communication.• Many companies that depend on international communication are already making use of such services in order to lower their operational costs.• Major corporations have done some significant research to fix the disadvantages of VoIP service, as well as improve the overall quality.• With all of the improvements continually going on with VoIP, it will soon be accepted by everyone as an acceptable alternative to PSTN.2/7/2013 HS 12
  • QUESTIONS?2/7/2013 HS 13
  • • Q1) Is it possible to use voip solutions in wifi enabled cellphones?• A1) Yes , it is possible. In many cellphone operating systems there are many softphone applications which enables voip usage. For example, SJPhone is an application deployed for Windows mobile 2005 OS
  • • Q2) Is it possible to call the PC from the phone is used in daily life?• A2) YES. It is possible by using DID. By the help of the special numbers which are assigned by the daily phone network to voip network, it is possible to provide the transition. This transmission is also called number of portability. (DID Number)
  • • Q3: What do you think about the differences in price between PSDN and VoIP?• A3: Voip networks uses IP networks and over these networks voice packages are transferred. Internet can be used in terms of IP network. So, there is no need to additional investment. However, PSTNs performs communication over the TDM and ATM networks which have high cost. So, cost advantage between them is very high and it explains the difference in cost.
  • VoIP Challenges• VoIP implementations face problems dealing with latency , echo and jitter• Echo: waving of voice• Latency: Changing in delivery time between voice packets• Jitter: Changing in delivery order of voice packets
  • VoIP ChallengesConnection Problems:• problems behind NAT between peers.• Echo and jitter occurs because of packet loss.• Internet stability problems can cause reliability problems and this discourages voip usage.• routing VoIP traffic through firewall may blocks voice packets transmission.