sip rtp rtcp implementation l.
Skip this Video
Loading SlideShow in 5 Seconds..
SIP/RTP/RTCP Implementation PowerPoint Presentation
Download Presentation
SIP/RTP/RTCP Implementation

Loading in 2 Seconds...

play fullscreen
1 / 13

SIP/RTP/RTCP Implementation - PowerPoint PPT Presentation

  • Uploaded on

SIP/RTP/RTCP Implementation. by George Fu, UCCS CS 525 Semester Project Fall 2006. Two Parts of the Project. Understand SIP, RTP and RTCP Implement SIP, RTP and RTCP. Voice To/From IP. Analog. Voice. CODEC: Analog to Digital. Compress. Create Voice Datagram. Add Header

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'SIP/RTP/RTCP Implementation' - petra

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
sip rtp rtcp implementation

SIP/RTP/RTCP Implementation


George Fu, UCCS

CS 525 Semester Project

Fall 2006

two parts of the project
Two Parts of the Project
  • Understand SIP, RTP and RTCP
  • Implement SIP, RTP and RTCP
voice to from ip
Voice To/From IP



CODEC: Analog to Digital


Create Voice Datagram

Add Header

(RTP, UDP, IP, etc)


iso reference model and voip standards

ISO Protocol layer

Protocols and standards


Codecs / Applications


H.323 / SIP / MGCP






FR, ATM, Ethernet, PPP, etc.

ISO Reference Model and VoIP Standards
sip messages methods and responses
SIP Methods:

INVITE – Initiates a call by inviting user to participate in session.

ACK - Confirms that the client has received a final response to an INVITE request.

BYE - Indicates termination of the call.

CANCEL - Cancels a pending request.

REGISTER – Registers the user agent.

OPTIONS – Used to query the capabilities of a server.

INFO – Used to carry out-of-bound information, such as DTMF digits.

SIP Responses:

1xx - Informational Messages.

2xx - Successful Responses.

3xx - Redirection Responses.

4xx - Request Failure Responses.

5xx - Server Failure Responses.

6xx - Global Failures Responses.

SIP Messages – Methods and Responses

SIP components communicate by exchanging SIP messages:

example of sip message
Example of SIP message


Via: SIP/2.0/UDP




Content-Type: application/sdp

Content-Length: 885

c=IN IP4

m=audio 38060 RTP/AVP 0

  • HTTP message syntax
  • sdp = session description protocol
  • Call-ID is unique for every call.
call to a known computer
Call to a known Computer
  • Alice’s SIP invite message indicates her port number & IP address. Indicates encoding that Alice prefers to receive (PCM ulaw)
  • Bob’s 200 OK message indicates his port number, IP address & preferred encoding (GSM)
  • SIP messages can be sent over TCP or UDP; here sent over RTP/UDP.
  • Default SIP port number is 5060.
  • Open All the Sockets in the Main Thread

sip_send_socket = socket (AF_INET, SOCK_DGRAM, 0);

rtp_send_socket = socket (AF_INET, SOCK_DGRAM, 0);

rtcp_send_socket = socket (AF_INET, SOCK_DGRAM, 0);

sip_receive_socket = socket (AF_INET, SOCK_DGRAM, 0);

rtp_receive_socket = socket (AF_INET, SOCK_DGRAM, 0);

rtcp_receive_socket = socket (AF_INET, SOCK_DGRAM, 0);

  • Separate Thread for RTP and RTCP

pthread_create(&child, NULL, send_RTP_RTCP, NULL);

  • Use Select System Call to Make SIP/RTP/RTCP/User Commands Send and Receive all Work Simultaneously
  • U. Black, Voice over IP, 2nd ed., Prentice Hall, 2002
  • J. Davidson and J. Peters, Voice over IP Fundamentals, Cisco Press, 2000
  • Douskalis, IP Telephony. The Integration of Robust IP Services, Prentice Hall, 2000.
  • H. Liu and P. Mouchtaris, “Voice over IP Signaling: H.323 and Beyond,” IEEE Comm. Mag., October 2000, pp. 142-148
  • H. Schulzrinne and J. Rosenberg, The Session Initiation Protocol: Internet-Centric Signaling,” IEEE Commun. Mag., Oct. 2000, pp. 134-141.
  • RFC 1889: H. Schulzrinne et al, “RTP: A Transport Protocol for Real-Time Applications”