3GPP All IP Network Speaker: Ai-Chun Pang

Presentation on theme: "3GPP All IP Network Speaker: Ai-Chun Pang"— Presentation transcript:

1 3GPP All IP Network Speaker: Ai-Chun Pang
Dept. of Comp. Sci. and Info. Engr. National Taiwan University

2 Next Generation Networks [1/2]
Internet Telecom & Wireless Communication Wireless LAN WLAN CA FA SIP Proxy Server Internet MS 3GPP CSCF 3G UMTS GGSN SGSN T-SGW MGW PSTN 3GPP MGCF Reference: CCL/ITRI

3 Next Generation Networks [2/2]
Internet Telecom & Wireless Communication App. Server 3rd Parties App. GPRS CSCF SIP Server Internet Wireless CSCF WLAN MGCF MGW T-SGW MGW IP PSTN Reference: CCL/ITRI

4 Mobile Technologies 1G (e.g., AMPS) 2G (e.g., GSM) 2.5G (e.g., GPRS)
3G (e.g., UMTS/cdma2000)

5 GPRS System Packet Switching Technology High Data Rate
Based on GSM Cellular Network Infrastructure GSM MSC/VLR PSTN PCU BSS HLR GPRS Gb Gn Gi External Data Network SGSN GGSN SGSN: Serving GPRS Support Node GGSN: Gateway GPRS Support Node

6 SGSN and GGSN GGSN SGSN IP based Network Serving GPRS Support Node
HLR IP based Network Serving GPRS Support Node . Mobility Management (Location Update, Paging etc.) . Access Control & Security (Authentication, Ciphering) . Operation Data, such as Billing Info. Gateway GPRS Support Node . Interworking between PDN and GPRS PLMN . PDU Tunneling . Operation Data, such as Billing Info.

7 GPRS MM/SM Mobility Management Attach Detach Security
Routing Area Update Session Management PDP Context Activation PDP Context Deactivation PDP Context Modification

8 3G IMT-2000 Year 2000 Ready Operate at 2000 MHz
Provide 2000K bps Data Rate 3G Data Rate 要求 Vehicular Kbps Pedestrian Kbps Indoor --- 2Mbps Three Important 3G Technologies Standards W-CDMA (Wideband CDMA) (歐日系統) cdma2000 (北美系統) TD-SCDMA (Time Division Synchronize CDMA) (大陸系統)

9 From 2G to 3G From voice service to rich, interactive multimedia-based service Permanent network connection with high data rate 384 Kbps to 2M bps Mobile access to high-quality video, audio, graphics and multimedia as fixed Internet Massive increase in network capacity To support billions of subscribers Global roaming Use single terminal to access identical services all around the world

10 3GPP All IP Architecture
Based on packet technologies and IP telephony for real time and non real time services An evolution from Release 99 specifications All IP core network should support release 99 CS terminals Radio Access Network (RAN) GERAN and UTRAN Core Network Based on the evolution of GPRS

11 3GPP All IP Network PSTN HSS CSCF MRF Internet RNC SGSN GGSN MGCF MGW
Signaling (SS7 or IP based) Circuit Packet (user traffic / signaling) Call control function Legacy mobile signaling network R-SGW Mh Ms 這是3GPP制定的Release Four & Five Network Architecture。 藍色虛線以下的部分是指Release 4制定的範圍，以上的部分則是Release 5。 若是您有聽過R99，那它跟R4的差別就在 - R4利用了Softswitch將Signal與 Media的架構精神，將原先的 MSC(Mobile Station Center)分割成MSC Server負責Signal、Media Gateway負責Media；也同樣用在GMSC上。 Release 4制定的部分，稱之為Circiut Switched Domain；Release 5制定的部分，稱之為Packet Switched Domain。3G的GPRS 部分延續2.5G的功能與角色，使得無線手機能夠對IP網路作Data Access資料的存取。而HSS(Home Subscriber Server)則類似2G GSM 系統的HLR(Home Location Register)，當然為求提供更多的Services，3G的 HSS需具備支援較多的功能。 至於CSCF(Call Session Control Function)是今天報告的一個重點，主要是負責Call Control 通話控制。MRF(Multimedia Resource Function)是作Media Mixing, Play Announcement,支援Multi-party Conferencing，類似H.323裡面的MCU，Softswitch架構中的Media Server 。 依此3GPP制定的架構來看 - 未來將是一個 All IP Core Network。 Paradigm shift - Packet switching overtaking circuit switching as the prime mechanism to support telecom IP-Technology Drivers of Convergence:Prevalence普遍, Simplicity Cx Mr HSS CSCF MRF Mg Mm Gi Gr Gc Internet Gi RNC Iu_PS Gn Gi SGSN GGSN Node B Iu_CS (user traffic) MGCF MS Gi Node B Mc PSTN Nb MGW MGW MS Iu_CS (control part) MAP MAP Mc Mc Nc MSC Server GMSC Server T-SGW Reference: CCL/ITRI

12 Circuit-Switched Services
Signaling (SS7 or IP based) Circuit Packet (user traffic / signaling) Call control function Legacy mobile signaling network R-SGW Mh MSC – Media Server Controller HSS Gr RNC Node B Iu_CS (user traffic) MS Node B PSTN Nb MGW MGW MS Iu_CS (control part) MAP MAP Mc Mc Nc MSC Server GMSC Server T-SGW

13 Packet-Switched Services
Signaling (SS7 or IP based) Circuit Packet (user traffic / signaling) Call control function HSS Gr Gc Internet Gi Iu_PS Gn Gi RNC SGSN GGSN Node B MS Node B MS

14 Real-Time PS Services HSS CSCF MRF Internet RNC SGSN GGSN R-SGW
Signaling (SS7 or IP based) Circuit Packet (user traffic / signaling) Call control function Legacy mobile signaling network R-SGW Mh Ms 如果只有 SGSN & GGSN, 是可以提供 Packet Data service. 但若要提供 Real-Time PS Service, 則必須要有 CSCF. Cx Mr HSS CSCF MRF Mg Mm Gi Gr Gc Internet Gi Iu_PS Gn Gi RNC SGSN GGSN Node B MS Node B MS

15 Interworking with PSTN
Signaling (SS7 or IP based) Circuit Packet (user traffic / signaling) Call control function Legacy mobile signaling network R-SGW Mh Ms 若要聯到 PSTN，當然就要加上 gateway. Cx Mr HSS CSCF MRF Mg Mm Gi Gr Gc Internet Gi Iu_PS Gn Gi RNC SGSN GGSN Node B MGCF MS Gi Node B Mc PSTN MGW MS T-SGW

16 3GPP All IP Network PSTN HSS CSCF MRF Internet RNC SGSN GGSN MGCF MGW
Signaling (SS7 or IP based) Circuit Packet (user traffic / signaling) Call control function Legacy mobile signaling network R-SGW Mh Ms 這是3GPP制定的Release Four & Five Network Architecture。 藍色虛線以下的部分是指Release 4制定的範圍，以上的部分則是Release 5。 弱是您有聽過R99，那它跟R4的差別就在 - R4利用了Softswitch將Signal與 Media的架構精神，將原先的 MSC(Mobile Station Center)分割成MSC Server負責Signal、Media Gateway負責Media；也同樣用在GMSC上。 Release 4制定的部分，稱之為Circiut Switched Domain；Release 5制定的部分，稱之為Packet Switched Domain。3G的GPRS 部分延續2.5G的功能與角色，使得無線手機能夠對IP網路作Data Access資料的存取。而HSS(Home Subscriber Server)則類似2G GSM 系統的HLR(Home Location Register)，當然為求提供更多的Services，3G的 HSS需具備支援較多的功能。 至於CSCF(Call Session Control Function)是今天報告的一個重點，主要是負責Call Control 通話控制。MRF(Multimedia Resource Function)是作Media Mixing, Play Announcement,支援Multi-party Conferencing，類似H.323裡面的MCU，Softswitch架構中的Media Server 。 依此3GPP制定的架構來看 - 未來將是一個 All IP Core Network。 Paradigm shift - Packet switching overtaking circuit switching as the prime mechanism to support telecom IP-Technology Drivers of Convergence:Prevalence普遍, Simplicity Cx Mr HSS CSCF MRF Mg Mm Gi Gr Gc Internet Gi Iu_PS Gn Gi RNC SGSN GGSN Node B Iu_CS (user traffic) MGCF MS Gi Node B Mc PSTN Nb MGW MGW MS Iu_CS (control part) MAP MAP Mc Mc Nc MSC Server GMSC Server T-SGW

17 HSS HSS (Home Subscriber Server) is the master database for a given user. Functionalities The HLR functionality required by the PS-Domain The circuit switched part of the HLR User control functions required by the IP multimedia (IM) subsystem HSS D C Gr Gc Mh Cx MSC Server GMSC Server SGSN GGSN R-SGW CSCF

18 3GPP All IP Network PSTN HSS CSCF MRF Internet RNC SGSN GGSN MGCF MGW
Signaling (SS7 or IP based) Circuit Packet (user traffic / signaling) Call control function Legacy mobile signaling network R-SGW Mh Ms 這是3GPP制定的Release Four & Five Network Architecture。 藍色虛線以下的部分是指Release 4制定的範圍，以上的部分則是Release 5。 弱是您有聽過R99，那它跟R4的差別就在 - R4利用了Softswitch將Signal與 Media的架構精神，將原先的 MSC(Mobile Station Center)分割成MSC Server負責Signal、Media Gateway負責Media；也同樣用在GMSC上。 Release 4制定的部分，稱之為Circiut Switched Domain；Release 5制定的部分，稱之為Packet Switched Domain。3G的GPRS 部分延續2.5G的功能與角色，使得無線手機能夠對IP網路作Data Access資料的存取。而HSS(Home Subscriber Server)則類似2G GSM 系統的HLR(Home Location Register)，當然為求提供更多的Services，3G的 HSS需具備支援較多的功能。 至於CSCF(Call Session Control Function)是今天報告的一個重點，主要是負責Call Control 通話控制。MRF(Multimedia Resource Function)是作Media Mixing, Play Announcement,支援Multi-party Conferencing，類似H.323裡面的MCU，Softswitch架構中的Media Server 。 依此3GPP制定的架構來看 - 未來將是一個 All IP Core Network。 Paradigm shift - Packet switching overtaking circuit switching as the prime mechanism to support telecom IP-Technology Drivers of Convergence:Prevalence普遍, Simplicity Cx Mr HSS CSCF MRF Mg Mm Gi Gr Gc Internet Gi Iu_PS Gn Gi RNC SGSN GGSN Node B Iu_CS (user traffic) MGCF MS Gi Node B Mc PSTN Nb MGW MGW MS Iu_CS (control part) MAP MAP Mc Mc Nc MSC Server GMSC Server T-SGW

19 CSCF [1/4] Call Session Control Function ICGW (Incoming Call Gateway)
Acting as a first entry point to perform routing of incoming calls CCF (Call Control Function) Call setup/termination and call state/event management Application level registration handling SPD (Serving Profile Database) Interacting with HSS to receive user profile information AH (Address Handling) Mapping between alias address (e.g., E.164 number) and transport address

20 CSCF [2/4] Proxy CSCF (P-CSCF) is the first contact point within IM CN subsystem. Its address is discovered by UEs following PDP context activation procedure. Behaving like a Proxy server defined in RFC2543 P-CSCF Discovery Use of DHCP (Dynamic Host Configuration Protocol) Transfer the P-CSCF address with the PDP Context Activation signaling to the UE 依CSCF所負責的工作，可將CSCF分為三大類。第一類稱為Proxy CSCF (P-CSCF)。它是IM系統中第一個的contact point。也就是說，當手機要進行即時多媒體通訊的時候，它會先將信令傳送至P-CSCF。由P-CSCF決定信令的傳遞路徑。所以每一個手機在執行完PDP context activation的程序後必須立即得到P-CSCF的位置。如何得知P-CSCF的位置？可藉由兩種方式: (1) 利用DHCP。 (2) 透過PDP context activation的信令得知。

21 CSCF [3/4] Serving CSCF (S-CSCF) performs the session control service for the UE. Maintaining a session state as needed by the network operator for support of the services Registration Behaving as a Registrar as defined in RFC2543 It accepts registration requests and makes its information available through the location database (e.g., HSS). Session Flow Interaction with service platform for support of advanced services S-CSCF位於home network中負責議程控制的部分。以註冊的角度來看，它的功能類似於SIP中的registra (或location server)。在處理議程的程序中，它必須負責和service platform聯繫以支援更先進的服務。

22 Service Platform Interface
本圖顯示了S-CSCF和Service platform之間的介面。

23 CSCF [4/4] Interrogating CSCF (I-CSCF) is the contact point within an operator’s network for all connections destined to a subscriber of that network operator, or a roaming subscriber currently located within that network operator’s service area. That is,I-CSCF is the first contact point within an operator’s network for incoming call signaling. Registration Assigning a Serving CSCF to a user performing SIP registration　 Session Flow Obtaining the S-CSCF address from HSS Routing a SIP request received from another network towards the S-CSCF (Serving Terminating UE) I-CSCF負責詢問HSS有關使用者的位置。因此，當有信令要傳送至使用者時，這個信令會先送至I-CSCF，以確定UE目前的位置以及狀態。

24 3GPP All IP Network PSTN HSS CSCF MRF Internet RNC SGSN GGSN MGCF MGW
Signaling (SS7 or IP based) Circuit Packet (user traffic / signaling) Call control function Legacy mobile signaling network R-SGW Mh Ms 這是3GPP制定的Release Four & Five Network Architecture。 藍色虛線以下的部分是指Release 4制定的範圍，以上的部分則是Release 5。 弱是您有聽過R99，那它跟R4的差別就在 - R4利用了Softswitch將Signal與 Media的架構精神，將原先的 MSC(Mobile Station Center)分割成MSC Server負責Signal、Media Gateway負責Media；也同樣用在GMSC上。 Release 4制定的部分，稱之為Circiut Switched Domain；Release 5制定的部分，稱之為Packet Switched Domain。3G的GPRS 部分延續2.5G的功能與角色，使得無線手機能夠對IP網路作Data Access資料的存取。而HSS(Home Subscriber Server)則類似2G GSM 系統的HLR(Home Location Register)，當然為求提供更多的Services，3G的 HSS需具備支援較多的功能。 至於CSCF(Call Session Control Function)是今天報告的一個重點，主要是負責Call Control 通話控制。MRF(Multimedia Resource Function)是作Media Mixing, Play Announcement,支援Multi-party Conferencing，類似H.323裡面的MCU，Softswitch架構中的Media Server 。 依此3GPP制定的架構來看 - 未來將是一個 All IP Core Network。 Paradigm shift - Packet switching overtaking circuit switching as the prime mechanism to support telecom IP-Technology Drivers of Convergence:Prevalence普遍, Simplicity Cx Mr HSS CSCF MRF Mg Mm Gi Gr Gc Internet Gi Iu_PS Gn Gi RNC SGSN GGSN Node B Iu_CS (user traffic) MGCF MS Gi Node B Mc PSTN Nb MGW MGW MS Iu_CS (control part) MAP MAP Mc Mc Nc MSC Server GMSC Server T-SGW

25 MGCF & MGW Media Gateway Control Function
Being PSTN signaling termination point Performing protocol conversion between the legacy (e.g., ISUP) and the All-IP network call control protocols Media Gateway Being PSTN transport termination point Interfacing UTRAN over Iu

26 3GPP All IP Network PSTN HSS CSCF MRF Internet RNC SGSN GGSN MGCF MGW
Signaling (SS7 or IP based) Circuit Packet (user traffic / signaling) Call control function Legacy mobile signaling network R-SGW Mh Ms 原本 MSC 旳功能，依 signaling 和 media 兩部份拆開。 這是3GPP制定的Release Four & Five Network Architecture。 藍色虛線以下的部分是指Release 4制定的範圍，以上的部分則是Release 5。 弱是您有聽過R99，那它跟R4的差別就在 - R4利用了Softswitch將Signal與 Media的架構精神，將原先的 MSC(Mobile Station Center)分割成MSC Server負責Signal、Media Gateway負責Media；也同樣用在GMSC上。 Release 4制定的部分，稱之為Circiut Switched Domain；Release 5制定的部分，稱之為Packet Switched Domain。3G的GPRS 部分延續2.5G的功能與角色，使得無線手機能夠對IP網路作Data Access資料的存取。而HSS(Home Subscriber Server)則類似2G GSM 系統的HLR(Home Location Register)，當然為求提供更多的Services，3G的 HSS需具備支援較多的功能。 至於CSCF(Call Session Control Function)是今天報告的一個重點，主要是負責Call Control 通話控制。MRF(Multimedia Resource Function)是作Media Mixing, Play Announcement,支援Multi-party Conferencing，類似H.323裡面的MCU，Softswitch架構中的Media Server 。 依此3GPP制定的架構來看 - 未來將是一個 All IP Core Network。 Paradigm shift - Packet switching overtaking circuit switching as the prime mechanism to support telecom IP-Technology Drivers of Convergence:Prevalence普遍, Simplicity Cx Mr HSS CSCF MRF Mg Mm Gi Gr Gc Internet Gi Iu_PS Gn Gi RNC SGSN GGSN Node B Iu_CS (user traffic) MGCF MS Gi Node B Mc PSTN Nb MGW MGW MS Iu_CS (control part) MAP MAP Mc Mc Nc MSC Server GMSC Server T-SGW

27 MSC Server Mainly comprising the call control and mobility control parts of a GSM/UMTS MSC Performing the connection control for media channels in a MGW MSC server + MGW = MSC

28 3GPP All IP Network PSTN HSS CSCF MRF Internet RNC SGSN GGSN MGCF MGW
Signaling (SS7 or IP based) Circuit Packet (user traffic / signaling) Call control function Legacy mobile signaling network R-SGW Mh Ms 這是3GPP制定的Release Four & Five Network Architecture。 藍色虛線以下的部分是指Release 4制定的範圍，以上的部分則是Release 5。 弱是您有聽過R99，那它跟R4的差別就在 - R4利用了Softswitch將Signal與 Media的架構精神，將原先的 MSC(Mobile Station Center)分割成MSC Server負責Signal、Media Gateway負責Media；也同樣用在GMSC上。 Release 4制定的部分，稱之為Circiut Switched Domain；Release 5制定的部分，稱之為Packet Switched Domain。3G的GPRS 部分延續2.5G的功能與角色，使得無線手機能夠對IP網路作Data Access資料的存取。而HSS(Home Subscriber Server)則類似2G GSM 系統的HLR(Home Location Register)，當然為求提供更多的Services，3G的 HSS需具備支援較多的功能。 至於CSCF(Call Session Control Function)是今天報告的一個重點，主要是負責Call Control 通話控制。MRF(Multimedia Resource Function)是作Media Mixing, Play Announcement,支援Multi-party Conferencing，類似H.323裡面的MCU，Softswitch架構中的Media Server 。 依此3GPP制定的架構來看 - 未來將是一個 All IP Core Network。 Paradigm shift - Packet switching overtaking circuit switching as the prime mechanism to support telecom IP-Technology Drivers of Convergence:Prevalence普遍, Simplicity Cx Mr HSS CSCF MRF Mg Mm Gi Gr Gc Internet Gi Iu_PS Gn Gi RNC SGSN GGSN Node B Iu_CS (user traffic) MGCF MS Gi Node B Mc PSTN Nb MGW MGW MS Iu_CS (control part) MAP MAP Mc Mc Nc MSC Server GMSC Server T-SGW

29 MRF Multimedia Resource Function
Performing multi-party call and multi- media conferencing functions The same function as an MCU in the H.323 network

30 3GPP All IP Network PSTN HSS CSCF MRF Internet RNC SGSN GGSN MGCF MGW
Signaling (SS7 or IP based) Circuit Packet (user traffic / signaling) Call control function Legacy mobile signaling network R-SGW Mh Ms Call已經建立後，雙方通話就是e2e, 不透過CSCF。 這是3GPP制定的Release Four & Five Network Architecture。 藍色虛線以下的部分是指Release 4制定的範圍，以上的部分則是Release 5。 弱是您有聽過R99，那它跟R4的差別就在 - R4利用了Softswitch將Signal與 Media的架構精神，將原先的 MSC(Mobile Station Center)分割成MSC Server負責Signal、Media Gateway負責Media；也同樣用在GMSC上。 Release 4制定的部分，稱之為Circiut Switched Domain；Release 5制定的部分，稱之為Packet Switched Domain。3G的GPRS 部分延續2.5G的功能與角色，使得無線手機能夠對IP網路作Data Access資料的存取。而HSS(Home Subscriber Server)則類似2G GSM 系統的HLR(Home Location Register)，當然為求提供更多的Services，3G的 HSS需具備支援較多的功能。 至於CSCF(Call Session Control Function)是今天報告的一個重點，主要是負責Call Control 通話控制。MRF(Multimedia Resource Function)是作Media Mixing, Play Announcement,支援Multi-party Conferencing，類似H.323裡面的MCU，Softswitch架構中的Media Server 。 依此3GPP制定的架構來看 - 未來將是一個 All IP Core Network。 Paradigm shift - Packet switching overtaking circuit switching as the prime mechanism to support telecom IP-Technology Drivers of Convergence:Prevalence普遍, Simplicity Cx Mr HSS CSCF MRF Mg Mm Gi Gr Gc Internet Gi Iu_PS Gn Gi RNC SGSN GGSN Node B Iu_CS (user traffic) MGCF MS Gi Node B Mc PSTN Nb MGW MGW MS Iu_CS (control part) MAP MAP Mc Mc Nc MSC Server GMSC Server T-SGW

31 T-SGW & R-SGW Transport Signaling Gateway Function
Mapping call related signaling from PSTN/PLMN on an IP bearer and sending it to the MGCF Providing PSTN/PLMNIP transport level address mapping Roaming Signaling Gateway Function Providing communication with a 2G/R99 MSC/VLR

32 3GPP IMS IP Multimedia (IM) CN subsystem
Comprising all CN elements for provision of multimedia services The IM subsystem (IMS) utilizes the PS domain to transport multimedia signaling and bearer traffic. The IMS attempts to be conformant to IETF “Internet standards”. SIP (Session Initiation Protocol) has been selected as the interfaces between the IM CN elements.

33 1. Bearer Level Registration: GPRS
IP MM CN Subsystem UE GPRS 1. Bearer Level Registration: GPRS 開機註冊時取得 QoS level. 2. PDP Context Activation 3. CSCF Discovery 4. Application Level Registration

34 Application-level Registration
Home Network App. Server HSS 3 4 6 7 8 I-CSCF S-CSCF 5 2 2 Visited Network P-CSCF P-SCSF 1 1 GGSN GGSN SGSN SGSN Radio Access Network Radio Access Network Reference: CCL/ITRI

35 P-CSCF I-CSCF HSS S-CSCF
Visited Network Home Network P-CSCF I-CSCF HSS S-CSCF UE 1. Register 2. Register 本圖顯示了Application Level Registration的步驟。其中註冊的信令利用標準的SIP信令，在I-CSCF和HSS之間則是透過DIAMETER通訊協定。 3. Cx-Query 3. Cx-Query Resp. 4. Cx-Select-Pull 4. Cx-Select-Pull Resp. 5. Register 6. Cx-Put 6. Cx-Put-Resp. 7. Cx-Pull 7. Cx-Pull-Resp. OK OK OK

36 Originating Home Network Terminating Home Network
Call Setup Diagram Originating Home Network Terminating Home Network App. Server App. Server HSS HSS 5 6 3 8 I-CSCF S-CSCF I-CSCF S-CSCF 4 7 9 2 Visited/Home Network Visited/Home Network P-CSCF P-CSCF 1 10 GGSN GGSN SGSN SGSN Radio Access Network Radio Access Network Originating Terminating Reference: CCL/ITRI

37 Session Flow Procedure
UE#1 S-CSCF#1 S-CSCF#2 UE#2 INVITE 在All IP網路中，通話建立可分為下列幾個步驟： 由UE1透過CSCF間的轉送將INVITE傳遞給UE2。 UE間執行capability exchange (如: 決定所使用的CODEC)。網路端由所決定的capability來執行resource reservation的動作。 SDP is 183. Final SDP is in PRACK. UE2接起電話，並開始通話。(acpang: 這時的200OK應該不必帶 SDP 了) SDP Final SDP Reserv Success Ringing 200 OK ACK

38 INVITE UE#1 P-CSCF S-CSCF#1 I-CSCF#2 HSS S-CSCF#2 P-CSCF UE#2
Visited Network#1 Home Network#1 Home Network#2 Visited Network#2 UE#1 P-CSCF S-CSCF#1 I-CSCF#2 HSS S-CSCF#2 P-CSCF UE#2 INVITE+SDP 100 trying 步驟一: 由UE1透過CSCF間的轉送將INVITE傳遞給UE2。 假設兩個UE位於兩個不同的visited network。 INVITE + SDP 100 trying Service Control INVITE + SDP 100 trying Location Query Response INVITE + SDP 100 trying Service Control INVITE + SDP 100 trying INVITE + SDP 100 trying

39 183 Session Progress + PRACK
Visited Network#1 Home Network#1 Home Network#2 Visited Network#2 UE#1 P-CSCF S-CSCF#1 I-CSCF#2 HSS S-CSCF#2 P-CSCF UE#2 183 (SDP) 183 (SDP) 183 (SDP) 183 (SDP) 步驟二: UE間執行capability exchange (如: 決定所使用的CODEC)。網路端由所決定的capability來執行resource reservation的動作。 183 (SDP) 183 (SDP) PRACK (Final SDP) Authorize QoS Resource PRACK (Final SDP) PRACK (Final SDP) PRACK (Final SDP) Authorize QoS Resource PRACK (Final SDP) 200 OK 200 OK 200 OK 200 OK 200 OK

40 ReservSuccess (COMET)
Visited Network#1 Home Network#1 Home Network#2 Visited Network#2 UE#1 P-CSCF S-CSCF#1 I-CSCF#2 HSS S-CSCF#2 P-CSCF UE#2 Resource Reservation Resource Reservation 有學弟告訴我 COMET 這個 method 已經被 UPDATE 取代. COMET COMET COMET COMET COMET 200 OK 200 OK 200 OK 200 OK 200 OK

41 Ring (180 Ringing) + 200 OK (Hang Up) + ACK
Visited Network#1 Home Network#1 Home Network#2 Visited Network#2 UE#1 P-CSCF S-CSCF#1 I-CSCF#2 HSS S-CSCF#2 P-CSCF UE#2 Ring Ring 步驟三: UE2接起電話，並開始通話。 Ring 200 OK Ring Ring Approval of QoS Commit Ring 200 OK Ringback Service Control 200 OK 200 OK Service Control 200 OK Approval of QoS Commit 200 OK ACK ACK ACK ACK ACK