Understanding MultiService Access and H.248

2 Day Course

This two-day instensive course examines Multiservice access using PPPoE/PPPoA/VLANs and H.248 (MEGACO). The next generation of telecommunications networks will be deployed using VoIP technology and soft switching replacing circuit switching and ISDN signalling. By deploying communications as multimedia streams over IP it is possible to extend the services from simple voice to improved voice quality, better bandwidth utilization and expanded services into video and television carried over the same technology. Already cost effective VoIP services have been deployed using H.323 and SIP over Intranet infrastructures.  However to integrate this with existing ISDN and SS7 architectures and eventually to replace local exchanges and transit exchanges in carrier networks requires large scale signalling and switching changes.

The next generation of telecommunications networks is likely to use IP and for efficient and high-speed quality of service switching deploy MPLS to select routes.

To build soft switches and distribute the switching function over a carrier level infrastructure, gateways will be controlled using H.248, called Media Gateway Control Protocol (MEGACO) by the Internet community.

This course will provide an intensive study of these technologies.

This course is availble on our public schedule, please review the available dates at the bottom of this page.

As an onsite training provider, we can deliver this course to any location in the UK, EMEA, US and Asia/Pac.


When you have completed this course you will be able to:

  • Describe how PPPoA functions today
  • Migrate access to PPPoE and VLAN operation with Gigabit Ethernet
  • Discuss the mechanisms used to carry voice over IP
  • Compare SIP, H.323 and Media Gateway Control Protocol
  • Employ MEGACO to build soft switches
  • Analyse H.248 protocol exchanges.
Hide all

Introduction To Next Generation Architecture (7 topics)

  • Current generation switching
  • Next generation IP Infrastructure
  • Access with PPPoA dn PPPoE
  • Switch Control protocols and interfaces
  • Switching Control: General Switch Management
  • Switching Function: MPLS and CES
  • Gateway Control : MEGACO/H.248

PPPoE Fundamentals (22 topics)

  • PPPoE/PPPoA Advantages and disadvantages
  • PPPoA operation recap
  • RFC1483
  • SNAP
  • OUI
  • Selecting bridging and routing protocols
  • VC selection by protocol
  • PPPoE Architecture
  • RFC2364/2516
  • Aggregation and links to service provision
  • IPCP and LPC peers
  • Linking to Service Providers
  • L2TP and other service provision
  • Maximum receiver unit considerations
  • PPPoE Active Discovery Initiation (PADI)
  • PPPoE Active Discovery Offer (PADO)
  • PPPoE Active Discovery Request (PADR)
  • Active Discovery Session-confirmation (PADS)
  • PPPoE Active Discovery Terminate (PADT)
  • PPP Session Stage
  • LCP Considerations
  • Security Considerations

Gigabit Ethernet and VLANs (10 topics)

  • Evolution of Ethernet
  • CSMA/CD and its replacement by Switching
  • Layer 1 presentations
  • Concept of a LAN and a VLAN
  • Bridging: 802.1d
  • Spanning Tree Delays
  • Proprietary extensions: PortFast
  • VLAN Trunking
  • 801.1Q
  • Selection of VLAN Identifiers

Precedence and Quality of Service (9 topics)

  • Mechanisms for QoS
  • Layer 3:
  • RSVP
  • DiffServ
  • MPLS
  • MPLS experimental Bits
  • Layer 2: 802.1P
  • Bits in shim header
  • Delivering QoS

Carrying Multimedia Conferences over IP (12 topics)

  • Voice over IP Concepts
  • Control Plane
  • Information Plane
  • Signalling functions
  • RTP
  • CODECs and Encoding Media
  • RTCP
  • Example SIP connection
  • Session Description Protocol
  • Defining media streams
  • Architecture of a Soft Switch

Media Gateway Control Protocol (MEGACO/H.248) (25 topics)

  • H.248 standards and versions
  • Components of MEGACO
  • Contexts
  • Terminations: trunks, lines and media streams
  • Root Terminations
  • Identities
  • Notifications
  • Events
  • Replies
  • Digit maps
  • Statistics
  • Commands
  • Add
  • Subtract
  • Modify
  • Service Change
  • Audit
  • Setting up a connection
  • Constructing a context
  • Adding terminations
  • Signalling on/off hook
  • Dialed digit detection
  • Terminating a connection
  • Subtracting terminations
  • Removing contexts

Analyzing Traces of MEGACO Call Flows (13 topics)

  • Call between two residential gateways
  • Call between Residential Gateway and Trunking Gateway
  • Call between two Trunking gateways
  • Call between Residential gateway and SS7 trunk in TGW
  • Call between ISDN trunk in TGW and SS7 trunk in TGW
  • Call from residential gateway to H.323 Terminal
  • Call from residential gateway to SIP user
  • MGC registrations: accepting and rejecting registration
  • IVR Usage
  • Supplementary Service
  • Call Transfer
  • Call Waiting
  • Conferencing

A basic knowledge of IP will be assumed. The necessary IP skills can be gained by attending the one of the following courses.