Applied Networking-IV (2231114)             Lecture Week-9      VOIP Description & Operation           Lecture by: Djadja....
VOIP Description & Operation                         VOIP                         2m00                  Description7-Jun-1...
What is Voice over IP (VoIP)?                  1010101000010        IP Packet           )))    1001010101010              ...
What is IP Telephony ?            ITU Definitions           VoIP : Use of Private Networks           Internet Telephony : ...
Audio Packet Transfer                                             …Digitization (e.g., sampling at 8kHz, 16 bits per sampl...
Sampling, Quantization,                   Encoding+127                                                            10101111...
VoIP Deployments                                      Phone to Phone            1998                       is mainly provi...
IP-to-IP Calls           IP-to-                               Internet7-Jun-10  Jun-         IMT MM-Biztel                ...
IP-to-PSTN Calls           IP-to-                                Internet               PSTN7-Jun-10  Jun-          IMT MM...
The Internet Multimedia Protocol Stack7-Jun-10  Jun-             IMT MM-Biztel                       MM-                  10
SIP and H.323 comparisons                   H.323                  SIP                                H.323    Minimal del...
SIP Protocol FlowSIP UA            INVITE            (with SDP)            100 Trying            407 Auth Req            A...
H.323 protocol flowH.323 Endpoint                                H.323 Endpoint                 Open logical channel inc  ...
SIP to H.323 Protocol Flow SIP UA                  IP-IP Gateway                           H.323          INVITE          ...
CiscoSIP-H.323 and H.323-SIP support was introduced in IOSSIP-           H.323-release 12.3(11)TSupports Voice calls. Vide...
SIP-H.323 Gateway Network   SIP-Architecture (Cisco IP-IP Gateway)                    IP-
SIP-H.323 Gateway NetworkSIP-H.323Architecture (Asterisk Server)
IP-IP International    IP-Gateway/Gatekeeper GDS  peering configuration
VOIP Description & Operation                   Operation7-Jun-10  Jun-                IMT MM-Biztel                       ...
Implications               No more time-based                telephony charges           No concept of local call, long-  ...
Change in Business Paradigm             Traditional Telecom Model                     New Telecom Model                   ...
Technical Issues            Technical Architecture      To achieve interoperability between different IP Telephony service...
Business Issues               Interconnection     Who can interconnect to PSTN?     What is the pricing model?            ...
Regulatory Issues                 Classification     How do we classify all the different IP Telephony services?     Are t...
Future                             Convergence                                5m00           Conclusion & Final Words7-Jun...
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Widyatama.lecture.applied networking.iv-week-09-voip

  1. 1. Applied Networking-IV (2231114) Lecture Week-9 VOIP Description & Operation Lecture by: Djadja.Sardjana, S.T., M.M. Djadja.Sardjana, www.slideshare.net/djadja Djadja.sardjana@widyatama.ac.id7-Jun-10 Jun- Widyatama University-Informatics University- 1
  2. 2. VOIP Description & Operation VOIP 2m00 Description7-Jun-10 Jun- IMT MM-Biztel MM- 2
  3. 3. What is Voice over IP (VoIP)? 1010101000010 IP Packet ))) 1001010101010 1001010101010 0101010001001 1010101000010 1001010101010 1001010101010 0101010001001 Internet/ Private IP Network 1010101000010 ((( 1001010101010 1001010101010 0101010001001 IP Packet 1010101000010 1001010101010 10010101010107-Jun-10 Jun- IMT MM-Biztel MM- 0101010001001 3
  4. 4. What is IP Telephony ? ITU Definitions VoIP : Use of Private Networks Internet Telephony : Use of Public Network IP Telephony : VoIP + Internet Telephony Alternatives This deployment is VoIP (end points are PSTN) End points are IP7-Jun-10 Jun- IMT MM-Biztel MM- 4
  5. 5. Audio Packet Transfer …Digitization (e.g., sampling at 8kHz, 16 bits per sample,i.e, 128 kb/s or 320 bytes per 20 ms)i.e,Real-Real-time compression/encoding (e.g., G.729A at 8 kb/s) compression/encoding G.729ATransport to remote IP address and port number overUDP (Why not TCP?)Processing on receiver side is the reverse Introduction to VoIP 5
  6. 6. Sampling, Quantization, Encoding+127 10101111…01101101 Encode each quantized sample into 8 bit code word +0 PCM: 8000 x 8 bits = 64 kb/s Other techniques (differential coding, linear prediction) 2.4 kb/s to 64 kb/s-127 Sample at twice the Round off samples to one highest voice frequency of 256 levels (introduces 2 x 4000=8000 Hz noise) (interval of 125 µsec) Introduction to VoIP 6
  7. 7. VoIP Deployments Phone to Phone 1998 is mainly provided by Service Provider or Private Network (E.g. Singtel’s 019) 1999 PC(Web) to Phone is mainly provided by Service Provider (E.g. Web2Phone) IP Phone to IP Phone 2002 is mainly provided by Service Provider or self Managed (E.g. Free World Dial) post Wireless IP Phone 2003 to Wireless IP Phone will be provided by whom? New Comer: Skype, Vonage etc.7-Jun-10 Jun- IMT MM-Biztel MM- 7
  8. 8. IP-to-IP Calls IP-to- Internet7-Jun-10 Jun- IMT MM-Biztel MM- 8
  9. 9. IP-to-PSTN Calls IP-to- Internet PSTN7-Jun-10 Jun- IMT MM-Biztel MM- 9
  10. 10. The Internet Multimedia Protocol Stack7-Jun-10 Jun- IMT MM-Biztel MM- 10
  11. 11. SIP and H.323 comparisons H.323 SIP H.323 Minimal delay - simplified Possibilities of delay (up to 7 or signalling scheme makes it 8 seconds!) A simple toolkit relative of "New World" - aupon which faster H.323 specifies everything "Old World" - complex, smart clients and - simple, open Internet protocols applications including the codec for the deterministic and vertical Slimbe built. It re-uses Net can and Pragmatic and horizontal The suite ishow cumbersome to media and too you carry the elements (URLs, MIME and deploy easily packets in RTP IETF ITU DNS) Seamless interaction with other Leaves issues of reliability to Services are nailed-down and- Assumes fallibility of network media - services are only limited underlying network constricted an unnecessary overhead Carrier-class solution addressing by the developers imagination Borne of the LAN - focusing on the wide area enterprise conferencing priorities Many vendors developing SIP messages are formatted as The majority of existing IP H.323 messages are ASN.1 products text. telephony products rely on the binary encoded, adding H.323 suite www.sipcenter.com complexity Taken from7-Jun-10 Jun- IMT MM-Biztel MM- 11
  12. 12. SIP Protocol FlowSIP UA INVITE (with SDP) 100 Trying 407 Auth Req ACK INVITE With auth 100 Trying 180 Ringing 200 OK (with SDP) ACK RTP BYE 200 OK
  13. 13. H.323 protocol flowH.323 Endpoint H.323 Endpoint Open logical channel inc TCS Call Proceeding Open logical channel Alerting Connecting RTP Close logical channel Close logical channel ACK
  14. 14. SIP to H.323 Protocol Flow SIP UA IP-IP Gateway H.323 INVITE (with sdp) 100 Trying Open logical channel inc TCS Call Proceeding Open logical channel Alerting 180 Ringing Connecting 200 OK (with SDP) ACK RTP Close logical BYE channel Close logical channel ACK ACK
  15. 15. CiscoSIP-H.323 and H.323-SIP support was introduced in IOSSIP- H.323-release 12.3(11)TSupports Voice calls. Video is supported for some callsNot a big performance impact, as no media transcoding isinvolved. At worst case, just copy the media stream from inputbuffer to output bufferCosts money (2 cisco routers, 1or 2 ‘expensive’ softwarelicense)
  16. 16. SIP-H.323 Gateway Network SIP-Architecture (Cisco IP-IP Gateway) IP-
  17. 17. SIP-H.323 Gateway NetworkSIP-H.323Architecture (Asterisk Server)
  18. 18. IP-IP International IP-Gateway/Gatekeeper GDS peering configuration
  19. 19. VOIP Description & Operation Operation7-Jun-10 Jun- IMT MM-Biztel MM- 19
  20. 20. Implications No more time-based telephony charges No concept of local call, long- distance call or IDD call7-Jun-10 Jun- IMT MM-Biztel MM- 20
  21. 21. Change in Business Paradigm Traditional Telecom Model New Telecom Model Value-Added Voice Service Data Service Value-Added Service Voice Service Data Service Infrastructure Infrastructure“The most powerful paradigm shift is the fact that applications are not woven into theplatforms. Now to be a phone company, you dont have to weave tightly the voice serviceinto the infrastructure. They (Vonage) turn voice into a application and shoot it across oneof these platforms. And, suddenly, youre in your business.” – Michael Powell, Chairman of FCC 7-Jun-10 Jun- IMT MM-Biztel MM- 21
  22. 22. Technical Issues Technical Architecture To achieve interoperability between different IP Telephony services, What should be the technical common platform? What are the technical specifications to adopt? Quality of Service What is the acceptable QoS for IP Telephony? How to ensure QoS? Security and Privacy How secure is IP Telephony? What about wiretapping requirements?7-Jun-10 Jun- IMT MM-Biztel MM- 22
  23. 23. Business Issues Interconnection Who can interconnect to PSTN? What is the pricing model? Market Studies What is the economic impact? How would it change the telco landscape? (cost to setup IP Telephony service ~= cost to setup Email service) Numberings What’s is the numbering plans for IP Telephony? How are numbers assigned for IP Telephony services? What if there is no service provider?7-Jun-10 Jun- IMT MM-Biztel MM- 23
  24. 24. Regulatory Issues Classification How do we classify all the different IP Telephony services? Are they subjected to similar “regulation”? Licensing Who needs to apply for license? What if there is no service provider? Universal Access Is it applicable to IP Telephony? How about emergency numbers?7-Jun-10 Jun- IMT MM-Biztel MM- 24
  25. 25. Future Convergence 5m00 Conclusion & Final Words7-Jun-10 Jun- Widyatama University-Informatics University- 25

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