SlideShare a Scribd company logo
Zack Chou
FreePBX Application
Introduce
• FreePBX Could Works For Private Branch Exchange (PBX)
• Requirement:
Hyper-V 2012 R2 VM
Linux OS: FreePBX
Standard PBX Service: Asterisk
FreePBX Application
• Automatic Dialing
• Automatic Switching
• Call Transfer
• Call Back
FreePBX Basic Function
DUS works depends on VOIP (Voice over Internet Protocol):
which is a technologies for delivery of
Voice communication
Multimedia session
over Internet Protocol network.
How FreePBX Works
• The Steps and Principles in originating
• VoIP telephone calls:
• Digitization of the analog voice signal
• Packetized for these digital information
• Encode audio and video with
audio codecs: u-law , a-law , G-711
video codecs: H.263
What is Voice over IP
Network Integration
Cluster
Dial Up Server Cluster
PSTN
VOIP
Gateway
Corp Net
DUS 1DUS 2DUS 3
Computer
VOIP Common Protocol
• Session Initiation Protocol (SIP)
• Real-time Transport Protocol (RTP)
• Inter-Asterisk eXchange (IAX)
• Skype protocol
• H.263
Session Initiation Protocol
• SIP design elements similar to the HTTP request/response transaction
model.
• Each transaction consists of a client request that invokes a particular
method or function on the server within one response.
• SIP reuses most of the header fields, encoding rules and status codes
of HTTP, providing a readable text-based format.
SIP Operation
Method Description
INVITE Session setup request or media negotiation. Used also to
hold &retrieve calls
ACK Acknowledgement for an INVITE transaction completion
OPTIONS Used as a query for remote's status & capabilities
BYE Terminating a session
CANCEL Used to cancel an on-going transaction
REGISTER Registers a user with a Proxy/Register
SIP Request
SIP Response Codes
100 Trying-Request has been received by a proxy/gateway
180 Ringing-The called party received the INVITE request, the
phone is ringing
181 Call is being forwarded
182 Queued-Invite has been received and will be processed in
a queue
183 Session Progress-Used to convey report of incoming
early-media
200 OK-successful transaction completion
302 Moved Temporarily-Forward call to a given contact
SIP Response
305 Use Proxy-Repeats a me call setup using a given proxy
400 Bad Request-General error
401 Unauthorized-The request requires user authentication
404 Not Found-The user does not exist at the specified domain
408 Request Time out
486 Busy here
5XX Server Failure
6XX Global failure
SIP Response
Asterisk Core Architecture
Digits 1209Hz 1336Hz 1477Hz
697Hz 1 2 3
770Hz 4 5 6
852Hz 7 8 9
941Hz * 0 #
DTMF Meaning
Dual-tone multi-frequency signaling (DTMF) is an in-band telecom
signaling system using the voice-frequency band over telephone lines.
That uses a set of eight audio frequencies transmitted in pairs to
represent signals by digits
• Syntax dtmfmode=inband , rfc2833 , info and auto
• Inband: This send tones as inband audio within the voice stream.
If the phone is set for RFC2833 and asterisk is set for
inband then you may not hear anything.
• rfc2833: This is another inband method, that sends DTMF tones
separately as specially encoded RTP packets,
distinct from audio packets.
DTMF Mode For SIP Configuration
• Syntax dtmfmode=inband , rfc2833 , info and auto
• info :This is an out-of-band method that sends the DTMF signals
within SIP on a separate network connection from the
media streams.
• auto: Asterisk use rfc2833 for DTMF relay by default
but will switch to audio DTMF tones such as µ-law or a-law.
If the remote side does not indicate support of rfc2833.
DTMF Mode For SIP Configuration
• peer: A SIP point to which Asterisk sends calls (a SIP provider).
The peer authenticates at registration.
• user: A SIP entity which places calls through Asterisk .
Users authenticate to reach services with their context.
• friend: Asterisk will create two objects, one peer and one user,
with the same name.
Asterisk SIP Type
Q&A

More Related Content

FreePBX Application Introduce

  • 2. • FreePBX Could Works For Private Branch Exchange (PBX) • Requirement: Hyper-V 2012 R2 VM Linux OS: FreePBX Standard PBX Service: Asterisk FreePBX Application
  • 3. • Automatic Dialing • Automatic Switching • Call Transfer • Call Back FreePBX Basic Function
  • 4. DUS works depends on VOIP (Voice over Internet Protocol): which is a technologies for delivery of Voice communication Multimedia session over Internet Protocol network. How FreePBX Works
  • 5. • The Steps and Principles in originating • VoIP telephone calls: • Digitization of the analog voice signal • Packetized for these digital information • Encode audio and video with audio codecs: u-law , a-law , G-711 video codecs: H.263 What is Voice over IP
  • 6. Network Integration Cluster Dial Up Server Cluster PSTN VOIP Gateway Corp Net DUS 1DUS 2DUS 3 Computer
  • 7. VOIP Common Protocol • Session Initiation Protocol (SIP) • Real-time Transport Protocol (RTP) • Inter-Asterisk eXchange (IAX) • Skype protocol • H.263
  • 8. Session Initiation Protocol • SIP design elements similar to the HTTP request/response transaction model. • Each transaction consists of a client request that invokes a particular method or function on the server within one response. • SIP reuses most of the header fields, encoding rules and status codes of HTTP, providing a readable text-based format.
  • 10. Method Description INVITE Session setup request or media negotiation. Used also to hold &retrieve calls ACK Acknowledgement for an INVITE transaction completion OPTIONS Used as a query for remote's status & capabilities BYE Terminating a session CANCEL Used to cancel an on-going transaction REGISTER Registers a user with a Proxy/Register SIP Request
  • 11. SIP Response Codes 100 Trying-Request has been received by a proxy/gateway 180 Ringing-The called party received the INVITE request, the phone is ringing 181 Call is being forwarded 182 Queued-Invite has been received and will be processed in a queue 183 Session Progress-Used to convey report of incoming early-media 200 OK-successful transaction completion 302 Moved Temporarily-Forward call to a given contact SIP Response
  • 12. 305 Use Proxy-Repeats a me call setup using a given proxy 400 Bad Request-General error 401 Unauthorized-The request requires user authentication 404 Not Found-The user does not exist at the specified domain 408 Request Time out 486 Busy here 5XX Server Failure 6XX Global failure SIP Response
  • 14. Digits 1209Hz 1336Hz 1477Hz 697Hz 1 2 3 770Hz 4 5 6 852Hz 7 8 9 941Hz * 0 # DTMF Meaning Dual-tone multi-frequency signaling (DTMF) is an in-band telecom signaling system using the voice-frequency band over telephone lines. That uses a set of eight audio frequencies transmitted in pairs to represent signals by digits
  • 15. • Syntax dtmfmode=inband , rfc2833 , info and auto • Inband: This send tones as inband audio within the voice stream. If the phone is set for RFC2833 and asterisk is set for inband then you may not hear anything. • rfc2833: This is another inband method, that sends DTMF tones separately as specially encoded RTP packets, distinct from audio packets. DTMF Mode For SIP Configuration
  • 16. • Syntax dtmfmode=inband , rfc2833 , info and auto • info :This is an out-of-band method that sends the DTMF signals within SIP on a separate network connection from the media streams. • auto: Asterisk use rfc2833 for DTMF relay by default but will switch to audio DTMF tones such as µ-law or a-law. If the remote side does not indicate support of rfc2833. DTMF Mode For SIP Configuration
  • 17. • peer: A SIP point to which Asterisk sends calls (a SIP provider). The peer authenticates at registration. • user: A SIP entity which places calls through Asterisk . Users authenticate to reach services with their context. • friend: Asterisk will create two objects, one peer and one user, with the same name. Asterisk SIP Type
  • 18. Q&A

Editor's Notes

  1.  specifically refer to the provisioning of communications services (voice, fax, SMS, voice-messaging) over the public Internet, rather than via the public switched telephone network (PSTN).
  2. . IP電話通過把語音訊號經過数碼處理、壓縮編碼打包、透過網路傳輸、然後解壓、把数碼訊號還原成聲音,讓通話對方聽到 H.323的子協定多且複雜性高,在許多技術上的問題受限,不容易針對新的應用作擴充功能��因此,IETF (Internet Engineering Task Force)分別在1999年8月提出MGCP(Media Gateway Control Protocol)協定與1999年3月的SIP(Session Initiation Protocol)新架構,試圖簡化H.323的複雜性
  3. RTP用來定義在因特網上傳輸音頻和視頻的標準包格式,在RFC 1889中予以定義。它由音頻和視頻傳輸工作組制訂,並於1996年頒佈。 RTP和RTCP連接緊密,RTP實施實際資料的傳輸,RTCP則就服務質量做出反饋
  4. 會話發起協議(SIP)是IETF建立VoIP通話連接的協定標準。SIP是一種應用層控制協議,用於和一個或多個參與者創建、修改和終止會話。SIP的結構與HTTP(客戶-伺服器協議)相似。客戶機發出請求,並發送給伺服器,伺服器處理這些請求後給客戶機回送一個響應。請求與響應形成一次交換(transaction)。 SIP是會話初始化協定的縮寫,是一種用於建立、修改和終止VOIP電話通話的IP電話信號協定。SIP由IETF 制訂,並作爲RFC 3261頒佈。 媒體閘道器控制協議(MGCP)是由思科和Telcordia提議的VoIP協議,它定義了呼叫控制單元(呼叫代理或媒體閘道器)與電話閘道器之間的通訊服務。MGCP屬於控制協議,允許中心控制台監測IP電話和閘道器事件,並通知它們發送內容至指定位址。在MGCP結構中,智慧呼叫控制置於閘道器外部並由呼叫控制單元(呼叫代理)來處理。同時呼叫控制單元互相保持同步,發送一致的命令給閘道器。
  5. 撥打方電話發送邀請 接收方電話發出並送回應答180–正在撥打 當接收方電話發出應答200–OK 撥打方電話回以確認應答,以告知對方 當通過Media Session RTP傳輸資料時,就可以通話了 當撥打方挂上電話後,會向接收方電話發出一個再見呼叫 撥打方電話會回以應答200–OK
  6. user: A SIP entity which places calls through Asterisk (A phone which can place calls only).