Thoroughly study Media Gateway Control Protocol (MGCP) through a process of lecture and hands-on training. Learn what MGCP is and how it works, and get a practical guide on how to use it. The lessons in this course are clear, very technical, and always practical, and the hands-on exercises allow you to investigate and reinforce each lesson. In this course, you'll examine how MGCP interoperates in the current telecommunications network as well as with SIP, going beyond the basics of the protocol and getting a big picture understanding of how it all fits together.

What You'll Learn

• How MGCP Works
• Where MGCP Fits
• Real-Time Transport Protocol
• Session Description Protocol
• Media Gateway Control Interface
• Gateway Control Commands
• States, Failover, and Race Conditions
• MGCP Call Flow and Call Flow Traces

Who Needs to Attend

People who want a technical, vendor-neutral explanation of how MGCP works, MGCP call flow, and why MGCP is important. Those responsible for media gateways or other applications involving internetworking between TDM and packet-based voice.

Prerequisites

• TCP/IP Networking
• Voice over IP Foundations

Follow-On Courses

There are no follow-ons for this course.

Course Outline

1. Introduction

• Relation with the H.323 Standards
• Relation with the SIP/SIP bis Standards
• MCGP
• Types of Gateways
• Where MGCP Fits
• MGCP Endpoints, Calls, and Connections
• Scope of MGCP
• Call Identifiers
• Connection Identifiers
• Definitions

2. Review Real-Time Transport Protocol (RTP)

• Time Stamp Mechanism
• Jitter Buffer Mechanism
• Silence Suppression
• RTCP - SDES, Sender, Receiver, Bye Packets
  • Round Trip, Packet Loss, Ave Jitter Calculation
• RTP Payload for DTMF Digits (RFC 2833)

3. Session Description Protocol (SDP)

• Attributes (a=)
• Bandwidth (b=)
• Connection Data (c=)
• E-mail Address and Phone Number (e=, p=)
• Encryption Keys (k=)
• Media Announcements (m=)
• Origin (o=)
• Protocol Version (v=)
• Repeat Interval (r=)
• SDP Simple Capability Declaration
• Session Information (I=)
• Session Name (s=)
• Start and Stop Times (t=)
• Time Zone Correction (z=)
• Universal Resource Identifier (u=)

4. Media Gateway Control Interface

• Model and Naming Conventions
• Types of Endpoints
• Digital Channel (DS0)
• Analog Line
• Announcement Server Access Point
• Interactive Voice Response Access Point
• Conference Bridge Access Point
• Packet Relay
• CALEA and Wiretap Access Point
• Endpoint Identifiers
• Calls and Connections
• Names of Calls
• Names of Connections
• Management of Resources and Attributes of Connections
• Special Case of Local Connections
• Names of Call Agents and Other Entities
• Digit Maps
• Names of Events
• Usage of SDP

5. Gateway Control Commands

• EndpointConfiguration
• NotificationRequest
• CreateConnection
• ModifyConnection
• DeleteConnection (from the Call Agent)
• DeleteConnection (from the VoIP gateway)
• DeleteConnection (multiple connections, from the Call Agent)
• Audit Endpoint
• Audit Connection
• Restart in Progress
• Return Codes and Error Codes
• Reason Codes

6. Media Gateway Control Protocol

• General Description
• Command Header
• Command Line
• Coding of the Requested Verb
• Transaction Identifiers
• Coding of the Endpoint Identifiers and Entity Names
• Coding of the Protocol Version
• Parameter Lines
• Response Acknowledgement
• Local Connection Options
• Capabilities
• Connection Parameters
• Reason Codes
• Connection Mode
• Coding of Event Names
• Requestedevents
• Signalrequests
• Observedevent
• Requestedinfo
• Quarantinehandling
• Detectevents
• Eventstates
• Restartmethod
• Bearer Information
• Format of Response Headers
• Formal Syntax Description of the Protocol

7. Encoding of the Session Description

• Usage of SDP for An Audio Service
• Usage of SDP in a Network Access Service
• Usage of SDP for ATM Connections
• Usage of SDP for Local Connections
• Transmission over UDP
• Providing the At-Most-Once Functionality
• Transaction Identifiers and Three Ways Handshake
• Computing Retransmission Timers
• Piggy Backing
• Provisional Responses

8. States, Failover, and Race Conditions

• Basic Assumptions
• Security, Retransmission, and Detection of Lost Associations
• Race Conditions
• Quarantine List
• Explicit Detection
• Ordering of Commands and Treatment of Disorder
• Fighting the Restart Avalanche
• Disconnected Endpoints

9. MGCP Call Flow Traces