In a single weeklong class, you will thoroughly study the IMS, including relevant wireless access systems that are used by the IMS. You will begin by studying the systems surrounding the IMS to gain a clear vision of the big picture. Once you understand where the IMS fits into the PSTN, you will study the IMS architecture through a process of lecture and hands-on training. You will learn key IMS protocols including SIP, SDP, H.248, COPS, and Diameter. Learn what each IMS component is and how it functions in an actual test network. The lessons in this course are clear, very technical, and always practical. Since at least 40% of them are hands-on, you can investigate and reinforce each lesson. In this course, you'll examine how IMS weaves into the current telecommunications network-both wired and wireless.

What You'll Learn

• How IMS fits into the big picture
• IMS architecture
• IMS protocols SIP, Diameter, H.248, SDP, and COPs
• SIP Uniform Resource Indicators (URIs)
• IMS-related IP services
• IMS call flow examples
• IMS security
• Instant messaging and presence

Who Needs to Attend

Those who want a technical explanation of the IMS architecture.

Prerequisites

• TCP/IP Networking
• VoIP Protocol Essentials: SIP

Follow-On Courses

• MEGACO (H.248) and the IMS

Course Outline

1. The IMS Standards Bodies

• 3GPP
• 3GPP2
• IETF
• Open Mobile Alliance (OMA)
• TISPAN

2. IMS for CDMA2000 and LTE

• LTE vs. CDMA2000 3G Architecture Comparison
• EPC Architecture
• IMS and 4G Interoperation (IM and VOLTE)
• IMS Connectivity into a CDMA2000 network (IM)
• IMS Connectivity into an LTE network (VOLTE)
• SIP Anchoring

3. IMS Architecture

• Components
  • HSS
  • Proxy-CSCF
  • Serving CSCF
  • Interrogating-CSCF
  • Policy Decision Function
• IMS Identifiers
• IMS Message Paths Introduction (Via and Record-Route)
• The Service Path
• Initial Filter Criteria Introduction

4. SIP Architecture

• Requests and Responses
• SIP Message Flow
• SDP introduction
• SIP Labs

5. IMS Service Path

• The Service Path
• Path Header (RFC 3327)
• Service-Route (RFC 3608)

6. The Via Path

• The Via: Header
• Establishing the Response Path
• Forking - Response Merging
• Loops and Spirals
• Max Forwards

7. The Route Path

• Route Path vs. Via Path
• Record-Route and Route Headers
• Establishing the Route Path
• The Role of the S, I, and P Proxies

8. IMS Identifiers

• IMSI
• UICC
• Home Network, Public ID, Private ID
• SIP IRU Format

9. Initial Filter Criteria (iFC)

• The User Profile
• How the iFC is Used
• Understanding XML
• Disjunctive and Conjunctive Normal Form
• Implementing a TAS

10. IMS Reference Points

• Gm, Mw, Cx, Dx, Sh, Si, Dh, Mm, Mg, Mi, Mj, Mk, Ut, Mr, Mp, Go, Gq, ISC
• Specific analysis of the Cx and Dx interfaces
• DIAMETER

11. DIAMETER

• DIAMETER vs. RADIUS
• AVPs
• SCTP vs. TCP
• IMS Command Values

12. SIP Headers (Basic)

• Via, Branch, Max-Forwards
• SIP Dialog (To, From, tag=fields, Call-ID:)
• CSeq, Contact: Expires:
• Proxy-Authentication:, Proxy-Authorize:
• User-Agent:, Allow:, Supported:
• Content-Type:, Content-Length:

13. IMS SIP Headers (Advanced)

• P-Access-Network-Info
• P-Charging-Vector:, P-Preferred-Identity:, P-Asserted-Identity:, Authorization:
• Security-Client:, Security-Server:
• IMS Signaling Compression (SigComp Architecture)

14. Session Description Protocol (SDP)

• Session Parameters
• SDP Format
• Extending SDP
• SDPng
• Media Negotiation
• Changing Session Parameters

15. SIP Timers

• T1, T2, T4
• Timers A-K

16. IMS QoS Management

• IMS QoS Info Exchange During Call Setup
• New SDP Fields (RFC 3312)
• COPS Integration

17. IMS and the DNS

• DNS Basics
  • A-Record
  • The SRV Record (RFC2782)
  • How SIP uses the SRV Record (RFC3263 Locating SIP Servers)
  • How to Configure a SRV Record
  • The NAPTR Record (RFC2915)
• How the P-CSCF Locates the I-CSCF
• Introduction to ENUM (RFC3761: ENUM Protocol)
• How the S-CSCF uses ENUM

18. IMS Call Flow Examples

• Registration
• Service Discovery
• Identity Modules
• IMS Authentication and Key Agreement (User Identities)
• Service Triggers
• Initial Filter Criteria
• 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
• Control Models
• Role and Functions of HSS
• Third-Party Call Control
• Conferencing (REFER)
• Access and Location Information
  • P-Access
  • P-Visited
• IMS Messaging (Immediate, Session-Based, Deferred)

19. Charging and IMS

• Charging Entities and Functions
• P-Headers Related to Charging
• Diameter and How It's Used for Ro Interface

20. Security

• IPSEC
• Key Selection at Registration
• Security for Call Setup
• Authentication
• Securing the Media
• Privacy and Identity

21. 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

22. Organization of Subscriber Data

• Subscriber
• Data Related to Mobile Station Types
• Data Related to Authentication and Ciphering
• Data Related to Roaming
• Data Related to Basic Services

Labs

Lab 1: Start the IMS

Lab 2: Reset Open IMS

Lab 3: Test Open IMS

Lab 4: Manage Open IMS Using FHoSS

Lab 5: IMS Users Configuration

Lab 6: Configure an IMS User

Lab 7: Configure an Ethernet Phone as an IMS Client

Lab 8: Configure a True IMS Client on a WI-FI Connected Android Phone

Lab 9: Use Wireshark

Lab 10: Wireshark Call Flow - REGISTER

Lab 11: Wireshark Call Flow - REGISTER - INVITE

Lab 12: Service Profile Walkthrough

Lab 13; Implement a TAS

Lab 14: DNS Configuration

Lab 15: ENUM

Lab 16: Write a Service Profile

Lab 17: Roaming

Lab 18: Fome S-CSCF: Set

Lab 19: Registration Termination Request

Lab 20: Push Profile Request