Introduction to SIP Based ENUM IP Telephony Infrastructure 資策會 網路及通訊實驗室 Conference over IP Team 楊政遠 博士

Outline Review The Next Generation Converged Network SIP based IP Telephony System Integrate ENUM with SIP Based IP Telephony system The first run of SIP project in III NCL

Review PSTN –Signaling: System Signal No: 7 –Carrier: T1 and successors …... STP Local loop DTMF Signaling plane Bearer plane CPE CO

Review Internet (IP) Phone 1. ? 3. Digital voice packets 2. Call setup signaling AD/DA compress/decompress AD/DA compress/decompress

Review (cont.) Telephony Issues –Signaling Addressing –PSTN - SS7 (ITU E.164) –VoIP - H.323 、 SIP 、 MGCP 、 Megaco/H.248 Capability exchange –PSTN - Analog voice /  -law 、 A-law PCM –VoIP - Digital voice / G.711 、 G 、 G.729

Review (cont.) Telephony Issues –Bearer Transport –PSTN - TDM T1 trunk –VoIP - RTP over UDP/IP Delay and Jitter –PSTN - circuit switching / propagation delay –VoIP - packet switching / unbounded delay and jitter –Internetworking between PSTN & IP Telephony

Next Generation Converged Network

SIP based IP Telephony System INVITE SIP/2.0 ……. 180, Ringing 200, OK ACK RTP (voice) BYE ACK CallerCallee Pickup & dial Ringing Pick up On-hook SIP BASIC Call flow

SIP based IP Telephony System Redirect Server Location Server Registrar Server User Agent Proxy Server Gateway PSTN SIP Components Proxy Server SIP Distributed Architecture

SIP proxy server INVITE SIP/2.0 ……. Proxy server INVITE SIP/2.0 ……. Maybe rewrite SIP request Location server ? User Agent Proxy servers are, for example, used to route requests, enforce policies, control firewalls. SIP based IP Telephony System

redirect server Location server ? Proxy server or caller INVITE SIP/2.0 …………. 302 moved temporarily contract ……. INVITE SIP/2.0 ……. ACK Unlike a proxy server, it does not initiate its own SIP request. Unlike a user agent server, it does not accept call. SIP redirect server SIP based IP Telephony System

Simple SIP call setup and teardown 302 (Moved Temporarily) INVITE 200 (OK) ACK INVITE 302 (Moved Temporarily) ACK INVITE 180 (Ringing) 200 (OK) ACK RTP MEDIA PATH BYE 200 (OK) Call Teardown Media Path Call Setup INVITE Location/Redirect ServerProxy Server User Agent INVITE

SIP based IP Telephony System SIP based IP Telephony System must support SIP Based Call Control and Switching Operation System Support Feature and Application Creation

SIP based IP Telephony System CDR Server(s) Feature Server(s) Provisioning Server(s) 3 rd Party Billing System RADIUS SNMP Network Manager Clearing House Internet SIP proxy Server PSTN Gateway SIP proxy Server SIP IP Phone MGCP Device MGCP/SIP Translator SIP proxy Server H.323/SIP Translator SIP proxy Server H.323 Terminal SIP based VOCAL System [

H.323 Translator: Acts as a Gatekeeper to control H.323 endpoints. Talks SIP to the rest of the network for routing and features. SIP based IP Telephony System

MGCP Translator: Acts as a call agent to control MGCP end points. Talks SIP to the rest of the network for routing and features. SIP based IP Telephony System

SIP proxy Server: Acts as a trusted boundary for calls entering or leaving a network. Provides authentication and collects billing information for the CDR server.

CDR Server: Collects billing information from Marshal Servers and interfaces with billing systems using the RADIUS accounting protocol. SIP based IP Telephony System

Provisioning Server: Used to provision, configure and manage subscribers and servers from a GUI. SIP based IP Telephony System

Feature Server: Provide CPL based or XML scripts that run basic telephony features. SIP based IP Telephony System

SIP proxy server 1. Invite 2. Invite 3. Invite SIP Phone Basic call initiation SIP based IP Telephony System SIP proxy server

Basic call establishment , Ringing , Ringing6. 180, Ringing , OK8. 200, OK9. 200, OK 10. ACK 11. ACK 12. ACK 13. RTP SIP Phone SIP based IP Telephony System SIP proxy server

Basic call tear down Redirect 14. BYE15. BYE16. BYE , OK , OK , OK 20. Tear down SIP Phone RTP SIP based IP Telephony System SIP proxy server

Operation System Support (OSS) includes –Provision adding and maintaining network users –Authentication Access list / Digest –Billing –Network management SIP based IP Telephony System

Billing (CDR ends to record) SIP Proxy 13. BYE 15. BYE17. BYE , OK , OK , OK SIP Phone CDR server 16. Notify for end record14. Notify for end record 21. Tear downRTP SIP Proxy SIP based IP Telephony System

Feature services are the value-added functions of the phone system –Core features Calling Information –Calling Number Delivery (CND) or Calling Line Identification (CLID) / Calling Party Identity Blocking (CIDB) Calling Forwarding –Forward All Calls (CFA) / Forward - No Answer Mode (CFNA) / Forward - Busy Mode ( CFB ) Call Blocking / Call Screening –Set features Call transfer / Call Return / Call waiting / Cancel Call Waiting ( CCW ) –Scriptable features Call Processing Language (CPL) SIP based IP Telephony System

Features service - call blocking SIP proxy Call blocking feature server Redirect SIP Phone 1. Invite 2. Invite 4. ACK , move Invite , Forbidden 4. ACK 5, 403 Forbidden SIP based IP Telephony System

ENUM SIP Based Telephony system Gateway SIP proxy SIP Proxy SIP Phone 1. Invite 7. Invite 11. PSTN Gateway ENUM DNS 2. ENUM DNS Query 3. NAPTR RR 4. Front End Protocols Clearinghouses 5. Gateway location SIP phone to PSTN 6. Invite

ENUM SIP Based Telephony system PSTN to SIP phone SSP SCP PSTN STP Softswitch Media Gateway ENUM DNS1. ENUM Query 2. NAPTR RR DNS 3. DNS Query 4. A RR SIP proxy 5. Invite 6. Invite 7. Invite SIP proxy

ENUM SIP Based Telephony system PSTN to SIP phone SSP SCP PSTN STP Softswitch Media Gateway , Ringing , Ringing SIP proxy , Ringing , OK , OK , OK 20. ACK 21. ACK22. ACK DNS ENUM DNS 23. RTP 23. voice

Thanks !