SIP and the IMS

Powerful 5-Day Hands on Course

Course Description

This course is a detailed review of the SIP protocol. The emphasis is on the protocol itself, not any specific application of SIP. Hands on training is used at least 50% of the course. This course is very popular and the course reviews are "raving".

Intended Audience

This course is intended for technical personnel that need a vendor neutral understanding of the SIP protocol.

Prerequisites

Student prerequisites are as follows: TCP/IP, VoIP, and Gatekeeper knowledge and understanding.

Course Outline

1. Why does IMS use SIP?
• Circuit vs. packet concepts
• Circuit-based bearer channel vs. Packet-based bearer channel (DS0 vs. RTP)
• SS7/ISDN vs. SIP, MEGACO
• The IMS universal network design goal – build one horizontal network that can support all mobile services from one network
• VoIP Protocols comparison
• Why SIP?
• A short history of SIP
2. IP Routing and Switching Overview
• IP Routing
• Ethernet Essentials
3. TCP and UDP Essentials
• How VoIP uses TCP
• How VoIP uses UDP
4. IMS Architecture
• IMS and SIP
• RTP Introduction
• 3GPP/3GPP2, IETF, OMA (Open Mobile Alliance)
• Applications: Push to Talk, Instant Messaging, Presence, Telephony, Gaming
• Proxy-CSCF
• Serving-CSCF
• Interrogating-CSCF
• Policy Decision Function
• HSS
5. SIP Architecture
• The SIP architecture
• UA, Proxy, Redirect, Forking,
• Multimedia Architecture
• RTP/RTCP
• SDP
• Methods
• REGISTER
• INVITE and ACK
• UPDATE
• OPTIONS
• CANCEL
• REFER
• SUBSCRIBE and NOTIFY
• MESSAGE
• BYE
• SIP responses
• 1xx   Informational
• 2xx   Final
• 3xx   Redirection
• 4xx   Client Error
• 5xx   Server Error
• 6xx   Global Failure
6. SIP Uniform Resource Indicators (URIs)
• Generic URI information (RFC 2396)
• Direct or Proxy
• PSTN number (RFC 2808)
• Instant messaging
• Presence
• In registrations
7. SIP Headers
• Via
• Branch
• Max-Forwards
• Dialog (To, From, and tag= fields)
• CSeq
• Call-ID
• Contact
• SIP reliability
• Expires
• Authentication
• IMS Signaling compression (SigComp architecture)
8. Session Description Protocol (SDP)
• Learn how SIP uses SDP to define technical parameters that support a voice over IP media channel.
• Session parameters
• SDP format
• Extending SDP
• SDPng
• Media negotiation
• Changing session parameters
9. IMS Related IP Services
• DHCP
• ENUM
• DNS NAPTR records
• DNS SRV records
• Regular Expressions
• DDDS algorithm
10. SIP Call Flow Examples
• Call attempt – unsuccessful
• Presence subscription
• Registration
• Registration with Authentication
• Presence notification
• Instant Message Exchange
• Call setup – successful
• Call hold
• Call Forward
• Call transfer
• Unified messaging
11. IMS Reference Points
• Gm, Mw, Cx, Dx, Sh, Si, Dh, Mm, Mg, Mi, Mj, Mk, Ut, Mr, Mp, Go, Gq
12. IMS Call Processing  
• Registration
• Service discovery
• Identity modules
• IMS Authentication and key agreement (User Identities)
• Network domain security
• Secure HTTP-based service
• Controlling bearer traffic
• Controlling the Media
• Anonymous calling (Hide Caller-ID)
• S-CSCF assignment processes
• MEGACO and SIP controlled PSTN connectivity
• Creation of via-path for response routing
• Response merging
• Record route
• Control models
• Third party call control
• Conferencing (REFER)
• Access and location information
• P-Access
• P-Visited
• IMS Messaging (Immediate, Session-based, Deferred)
13. RTP and RTCP (Real-Time Control Protocol)
• Dealing Packet Loss, Latency, Jitter
• How RTP defines the session
• Session Description Protocol
• The RTP profile
• The RTP payload type field
• RTP telephony events (RFC 2833)
• How RTP removes jitter
• How RTP handles packet loss
• How RTP identifies the talking party
• How RTP handles silence suppression
• How RTP handles fixed length packets (padding)
• How RTP is used to mix voice (conference calls)
• The RTP header
• RFC 2833 protocol
• RTP Control Protocol (RTCP)
• SDES
• Sender/receiver reports
• Bye reports
14. IMS Presence
• SIMPLE - SIP for Instant Messaging and Presence Leveraging Extensions
•  Terminology
•  Framework
•  Resource List Manipulation Requirements
•  Authorization Policy Manipulation
•  Acceptance Policy Requirements
•  Notification Requirements
•  Content Requirements
•  General Requirements
15. SIP Timers
• T1, T2, T4
• Timer A – K
16. IMS Security
• Security for call setup
• Authentication
• S/MIME
• TLS
• Privacy and identity
• Diameter

Course Labs

• Configure PCs and Build an IP network
• Learn how to use Ethereal
• Configure the SIPURA ATA
• Configure X-Lite SIP Client
• Model the CSCF functions using the ONDO SIP Proxy
• asterisk@home
• Perform Call traces with ethereal and SIP UAs
  • SIP REGISTER without authentication
  • SIP REGISTER with authentication
  • Simple SIP Call without INVITE authentication
  • SIP call with INVITE authentication
  • 100rel  (PRACK)
  • Busy call
  • Vacant Number
  • Abandoned Call
  • DTMF - SIP INFO
  • DTMF - RFC 2833
  • DTMF – in band
  • SIP NOTIFY (voice mail indication example)
  • Call Forward Immediate
  • Call Forward No Answer
  • Call Transfer (REFER)
  • Bye message with RTCP call information
  • SIP Timers effect on call processing
  • Model the IMS using multiple layers of proxies