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KX-TDA200/100 System (Version 2.0)

KX-TDA200/100 System (Version 2.0). Chapter 3 VoIP. Panasonic Communications Co., Ltd. Network Business Company Edition 1.0 10 Sep., 2004. Chapter 3 VoIP. 3. VoIP (1)Legacy Telephone and IP Telephone (2)Structure of packet of VoIP (3)Installation of VoIP in home

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KX-TDA200/100 System (Version 2.0)

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  1. KX-TDA200/100 System(Version 2.0) Chapter 3 VoIP • Panasonic Communications Co., Ltd. • Network Business Company • Edition 1.0 10 Sep., 2004

  2. Chapter 3 VoIP 3. VoIP (1)Legacy Telephone and IP Telephone (2)Structure of packet of VoIP (3)Installation of VoIP in home (4)Installation of VoIP in business (5)Voice Codec (6)VoIP Protocol (7)Problem of VoIP (8)QoS(Quality of Service)

  3. (1)Legacy Telephone and IP Telephone(1/4) (a)Legacy Telephone The line is used exclusively by the communication. Circuit Switched System CO(Transit Switch) CO(Transit Switch) CO(Transit Switch) 03-****-0002 06-****-0082 CO(Local Switch) CO(Local Switch) Called party is identified by the telephone number. 03-****-0001 06-****-4415 Dial 06-****-4415 The voice data is always directly connected while talking status.

  4. (1)Legacy Telephone and IP Telephone(2/4) (b)IP Telephone Wide sense Narrow sense IP Telephone IP Telephone Internet Telephone To use the Proprietary IP Network of ISP To use the Internet

  5. (1)Legacy Telephone and IP Telephone(3/4) (b)IP Telephone Packet Switched System Two or more users can share the line. The using efficiency of the line goes up. Call IP Phone B (IP address xxx.yyy.zzz.001） IP cloud Rooter Rooter Rooter Rooter Rooter Rooter Rooter IP Phone B (IP address xxx.yyy.zzz.001) IP Phone A (IP address aaa.bbb.ccc.001) The Called party is identified by IP address for the IP telephone. The voice data is divided, and transmitted as IP packet.

  6. (1)Legacy Telephone and IP Telephone(4/4) (c)Point of difference Item Legacy Telephone IP Telephone Switching Circuit Switching Packet Switching Called party identification Telephone Number IP Address Guaranteed Not guaranteed Quality Influence of traffic Influenced (Necessary data might not be able to be transmitted.) Not influenced Provided service from PSTN only. Many services are available. Service Simple Network Intelligent Terminal Intelligent Network Simple Terminal Basic concept

  7. (2)Structure of packet of VoIP(1/3) (a)Making procedure of IP data of voice Original voice(analogue) (1) Original voice is digitalized. Digitalized voice data Voice data 1 Voice data 2 Voice data 3 Voice data 4 Voice data… (2) It cuts in pieces and take it apart. Voice data 2 Voice data 3 Voice data 4 Voice data… Voice data 1 Voice data is encapsulated by RTP (3) The address is applied. IP UDP RTP Voice data 1 Voice packet There is a necessity for sending information (header) other than original voice data.

  8. (2)Structure of packet of VoIP(2/3) (b)Header information RTP Header - Sequence number of packet - Timestamp for detecting delay time of packet RTP Packet RTP Header Voice data UDP Header - Port number to identify the application. UDP Data gram UDP Header IP Header - IP address to identify the party - TOS - TTL - Header size IP Packet IP Header Hello IP Packet IP network VoIP Gateway Analogue Telephone

  9. (2)Structure of packet of VoIP(3/3) (c)Packet size RTP Packet (Byte) RTP Header Voice data - It is efficient when the voice size sent by one time is enlarged. However, the delay increases. - If G.729 is used, the data of 20 Bytes (Two voice data of the amount of 10ms) is usually put. 20 12 UDP Data gram UDP Header (Byte) 20 12 8 20 60B=40B(Header)+20B(Voice data) Header is doubled size of Voice data. IP Packet IP Header (Byte) 20 8 12 20 40 bytes Only the header 40 Hello IP Packet IP network VoIP Gateway Analogue Telephone It is necessary to send 50 Packets / 1s to the party, when it is put 1 Packet / 20ms(Voice data).

  10. (3)Installation of VoIP in home(1/5) Subscriber Telephone & Subscriber Telephone Traditional telephone service of PSTN Telephone Network & ISDN CO(Local Switch) CO(Local Switch) 06-****-4415 03-****-0001

  11. (3)Installation of VoIP in home(2/5) Soft Phone & Soft Phone Telephone which uses PC PC - PC connection type Internet Telephone Talking through Internet Internet Without Telephone Number Without Telephone Number Talking with VoIP Connected the Communication software and MIC & Speaker

  12. (3)Installation of VoIP in home(3/5) Soft Phone & Subscriber Telephone PC – Subscriber Telephone connection type Internet Telephone Talking through Voice GW from Internet Internet Telephone Network & ISDN Local Switch 06-****-4415 Voice GW Without Telephone Number Talking with VoIP VoIP GW It is not possible to receive the call because there is no telephone number. - Digitalization of Voice signal and packetization. - Telephone number converts IP address and IP address converts Telephone number.

  13. (3)Installation of VoIP in home(4/5) Subscriber Telephone & Subscriber Telephone Tandem type Internet Telephone service Only the long distance line part uses Internet and carrier's IP network. Talking through Voice GW from Internet Internet / Telephone Network & ISDN Proprietary IP Network Telephone Network & ISDN Local Switch Local Switch 06-****-4415 03-****-0001 Voice GW Voice GW Talking with VoIP It is possible to operate both receiving call and originating call.

  14. (3)Installation of VoIP in home(5/5) Subscriber Telephone & Subscriber Telephone IP Subscriber telephone service Talking with VoIP FTTH ADSL VoIP Converter 050-****-4401 Proprietary IP Network VoIP converter 050-****-4400 Telephone Network & ISDN Local Switch 06-****-4415 Voice GW Talking with VoIP

  15. (4)Installation of VoIP in business(1/4) (a)Leased line connection CO call CO call Telephone Network & ISDN Leased line Extension to Extension call Leased line Terminal Host Computer Head office Branch office

  16. (4)Installation of VoIP in business(2/4) (b)Installation of VoIP CO call CO call Telephone Network & ISDN Gate keeper It manages telephone number and IP address, uniformly, when ITU-T recommendation H.323 protocol is used. VoIP Gateway VoIP Gateway Extension to Extension call Rooter Rooter Leased line Terminal Host Computer Head office Branch office

  17. (4)Installation of VoIP in business(3/4) (c)Installation of VoIP - IP Trunk CO call CO call Telephone Network & ISDN IP Trunk IP Trunk Extension to Extension call Rooter Rooter Leased line (IP-VPN) Terminal Host Computer Head office Branch office

  18. (4)Installation of VoIP in business(4/4) (d)Installation of VoIP – Full IP Gate Keeper Gate Keeper SW HUB SW HUB IP Extension IP Extension Extension to Extension call Rooter Rooter Leased line, IP-VPN, etc. IP Extension IP Extension Internet FAX Internet FAX CO call CO call VoIP Gateway VoIP Gateway Telephone Network & ISDN Head office Branch office

  19. (5)Voice Codec(1/2) MOS (Mean Opinion Score) 5 Excellent G.711 PCM G.728 LD-CELP G.726 G.727 ADPCM 4 G.729 (ISDN, T1, E1) G.723 CS-ACELP (DECT) Good MP-MLQ ACELP 3 Fair 2 Poor 1 Bad 2 4 8 16 32 64 kbps TDA System supported

  20. (5)Voice Codec(2/2) PCM(G.711) Amplitude of voice Time Sampling by eight bits as for 1/8000 seconds. CELP(G.729) Pattern of voice wave form Speaker's characteristic - Volume of voice - Height of voice -Timing by which word is cut - etc.

  21. (6)VoIP Protocol(1/6) • What is VoIP Protocol? Protocol which control the Call. Processing Call Control - Detect the Off-Hook and sends the progress tone - Receive the the dial number of called party - Start to ring the called party a sent the Ring-back Tone - Detect the answer of the called party. • What is Call Protocol? ITU-T H.323, SIP, MGCP

  22. SIP IETF Text SIP Server UDP Windows Messenger (WIN XP) The operation equipment is few There is the delay of the Standardization of enhancing specification. High affinity of WEB and DNS server. (6)VoIP Protocol(2/6) (a)Point of difference Item H.323 MGCP Standardization Organization ITU-T IETF Data Format Binary Text Call control server Gate Keeper MG Controller Call control Protocol TCP, UDP UDP Application of Microsoft - NetMeeting Some cable operators are using it. Actual achievement Many models use this Others It is designed to construct a large-scale VoIP network. This is commonly used in a business use.

  23. (6)VoIP Protocol(3/6) (b)H.323 Protocol Stack AV APR. Call Control and Management Data APR. 7 Voice Video H.225.0 (RTCP) H.225.0 (RAS) H.225.0 (Q.931) H.245. T.124 T.125 H.261 G.711 G.722 G.723G.728 G729 6 H.225(RTP) 5 4 UDP TCP T.123 Network Layer(IP) 3 2 Link Layer(MAC/PPP/Q.922) Physical Layer 1 RTP( Real time Transport Protocol ) This treats the time stamp and the order number to take time synchronization by transmitting and receiving. :Used for the VoIP RTCP( Real time Control Protocol ) This controls the RTP transmission.

  24. (6)VoIP Protocol(4/6) (c)H.323 System configuration -Address Conversion -Control the recognition of connection -Control the Securing the bandwidth -Control the zone -Call control - Permission of Call requirement T : Terminal GK : Gatekeeper GW : Gateway MCU : Multi point Control Unit R : Router Voice Graphics data Control Protocol Conversion T1 GK GW T4 T5 T2 T3 R MCU R -Control the Multi Point connection -Processing of the Multi Point Signaling

  25. (6)VoIP Protocol(5/6) (d)H.225(RAS/Q931) <Example> Endpoint 1 Gatekeeper Endpoint 2 ARQ(1) ACF/ARJ(2) 1st. Phase Set-up(3) 2nd. Phase Call proceeding(4) ARQ(5) ACF/ARJ(6) Alerting(7) Connect(8) ARQ : Admission Request ACF : Admission Confirm ARJ : Admission Reject RAS(Registration/Admission/Status) Messages Call Signaling Message

  26. (6)VoIP Protocol(6/6) (e)H.245(Negotiation) <Example> Endpoint 1 Endpoint 2 Capacity Exchange Master Slave determination 3rd. Phase Open Logical Channel RTP/RTCP 4th. Phase Start the Conversation

  27. (7)Problem of VoIP(1/8) • Transmission delay The delaying of transmission of IP packet occurred. Sending the IP packet is waited until the transmission line can become empty, when the transmission line is congestion. Then, the delay becomes large. • Jitter (fluctuation of delay time) The delaying of transmission of IP packet becomes fluctuating. • Packet Loss Packets can be dropped if the network quality is poor, the network is congested, or there is too much variable delay in the network. Voice clipping and skips, often resulting in choppy and sometimes unintelligible speech

  28. (7)Problem of VoIP(2/8) • Echo It returns after my voice is sent to the called party side. Especially, there is a tendency generated easily when the delay is large. It is difficult to hear the voice • NAT problem When the IP masquerade is used, IP address included in the control message of VoIP cannot be converted. It is not possible to control the Call

  29. (7)Problem of VoIP(3/8) (a)Improved Transmission delay by Jitter buffer Voice is reproduced, after the packet is accumulated in the buffer once. This feature can be configured to help compensate for network congestion problems. Voice Packet From IP Network To PBX IP Gateway Jitter Buffer

  30. (7)Problem of VoIP(4/8) (a)Improved Transmission delay by Jitter buffer <Improve the voice quality> (1)Random sequence P1 P5 P4 P2 P3 P2 P5 P4 P3 P1 From IP Network Jitter buffer To PBX Counterchange (2)Packet loss P1 P5 P4 P1 P3 P1 P5 P4 P3 From IP Network Jitter buffer To PBX Copy (3)Jitter P1 P5 P4 P3 P2 P1 P5 P4 P3 P2 From IP Network Jitter buffer To PBX Irregularly Regularly

  31. (7)Problem of VoIP(5/8) (a)Improved Transmission delay by Jitter buffer <Improve the voice delay> (1) Reduce the buffer size P1 P5 P4 P1 P3 P2 P5 P4 P3 P2 From IP Network Jitter buffer To PBX Buffer length must be kept to minimum because it contributes to end-to-end Network delay.

  32. (7)Problem of VoIP(6/8) (b)Echo cancellation (1)No echo cancellation <Example> PBX PBX 100 ms Caller 10 ms 10 ms PT/SLT PT/SLT Router Router 10 ms 100 ms 10 ms (2)Echo cancellation Echo Cancellation <Example> PBX PBX 100 ms Caller 10 ms 10 ms PT/SLT PT/SLT Router Router From 150ms to 200ms is the limit of the delay.

  33. - IP address in the Payload cannot be converted. - As a result, IP transmission source address of the IP header and IP address in the Payload are different. (2) Header=X Payload=X Header=Y Payload=X IP address of the IP header is converted by the NAT function and the Masquerade function. Transmission source IP address = X -> Y (1) (7)Problem of VoIP(7/8) (c)NAT problem Internet Gate Keeper VoIP Gateway Rooter IP address=Y(Global IP Address) IP address=X(Private IP Address) IP Masquerade(NAPT) This function is convert between Global IP Address and Private IP Address.

  34. (7)Problem of VoIP(8/8) (c)H.323 NAT problem <Example> Gatekeeper VoIP Destination ARQ ACF/ARJ Set-up OK Call proceeding OK ARQ H.225(Call Control) ACF/ARJ OK Alerting OK Connect NG Capacity Exchange Master Slave determination H.245(Negotiation) Open Logical Channel RTP/RTCP A similar problem occurs in other protocols. Start the Conversation

  35. (8)QoS(Quality of Service)(1/7) • Reduced the delay and Jitter • Prevention of Packet loss • Securing of band of transmission QoS is necessary. - Priority of Queuing - Diffserv - RSVP - IEEE802.1P

  36. IP Network IP Network (8)QoS (Quality of Service)(2/7) (a)Priority of Queuing by TOS (1)Without Priority IPGW Router PT/SLT First in First out (2)With Priority IPGW Router PT/SLT High The voice is previously prior put out. low

  37. (8)QoS (Quality of Service)(3/7) (a)Priority of Queuing by TOS 0 1 2 3 4 5 6 7 (Bit) Norma(Low PRI.) Precedence Priority - 000 001 010 011 100 TOS IP Precedence(3bit) Urgent (High PRI.） TOS field(8bit) 101 110 111 For the Control Data IP Header TOS: Type Of Service IP Packet

  38. - The parameter is set to priority rising when the VoIP gateway sends the voice packet. - It used The TOS field in the IP header. (1) Analog Telephone -The router checks the TOS field of the IP packet in the queue. - And the router changes the processing order according to the height of priority. (2) VoIP Gateway Voice Packet The voice packet is processed by priority. (3) Transit processing Voice Packet Router Queue IP Telephone Data Packet It throws away the packet from the low priority, when the processing performance of the router is exceeded, (4) PC Delete (8)QoS (Quality of Service)(4/7) (a)Priority of Queuing by TOS

  39. (8)QoS (Quality of Service)(5/7) (b)DiffServ(Differentiated Services) 0 1 2 3 4 5 6 7 (Bit) - DSCP(6bit) Controlled by the DSCP which is used the Identification information TOS field(8bit) IP Packet Data IP Header DSCP:Differentiated Services Code Point DiffServ - DiffServ will not be based on priority, application, or flow. - DiffServ is rule based and offers a control mechanism for policy-based network management.

  40. IP-GW IP-GW (8)QoS (Quality of Service)(6/7) (c)RSVP(Resource reSerVation Protocol) • RSVP is operated on IP router. • This is to secure the bandwidth of the voice • before the communication, and to guarantee the • bandwidth of end to end. • The real-time data streaming cannot be guaranteed, • though RSVP can guarantee Bandwidth. • It is necessary to have RSVP function by all Router • which passes to use RSVP. PBX PBX Path Message PT/SLT PT/SLT Router Router Reserve Message

  41. (8)QoS (Quality of Service)(7/7) (d)IEEE 802.1p The IEEE 802.1p standard for QoS prioritization is a specification defining 3 bits within the IEEE 802.1Q field in MAC header. Layer 2 switches use this information to direct the forwarding process. 16 0 15 31 (Bit) 19 20 Priority (3bits) CFI (1bits) TPID(16bits) VLAN ID(12bits) 802.1p/Q tag L2 Frame Data MAC Header

  42. Chapter 3VoIP Thank you very much !

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