Networks Course

Carrier Packet Networks • Technologies • MPLS • MPLS VPNs • SLAs • CoS • Integration & Aggregation

MPLS and Carrier Networks course is dedicated to building a solid foundation on carrier packet networks and services, and the underlying ideas, the terminology, technologies, configuration, and operation … in plain English.

We cut through the marketing and buzzwords demystifying carrier packet networks and services, plus explain Service Level Agreements, virtual circuits, traffic profiles, Class of Service, QoS, Differentiated Services, convergence, integration and aggregation, network technologies like MPLS, and their relationship to TCP/IP … without bogging down in the details.

You will gain productivity- and career-enhancing knowledge of the components, structure and operations of carrier packet networks and services, plus how they are packaged, implemented and marketed by carriers and used by government, businesses and other carriers.

Course Objectives

This course is designed for both those who need a simple overview and introduction, and for those who need a solid base to come up to speed on the listed topics. The objective for those in the first group is not becoming an instant expert, but rather becoming familiar with the components, structure and operations of carrier packet networks and services, their packaging, marketing and use, and demystifying the jargon and buzzwords to eliminate frustration and increase your effectiveness and confidence. For those in the second group, the objective is to come up to speed on all (or most) of the topics, creating a base on which to build project- or job-specific knowledge.

On completion of the course, you will be able to:

 Explain the basic structure and components of a carrier packet network - customer edge, access, provider edge and core,

 List three reasons packet services are preferable over dedicated lines for wide-area networking,

 Define Class of Service, Service Level Agreement and traffic profile,

 Define a traffic class,

 Describe a virtual circuit and what it is used for,

 Differentiate between a unreliable and reliable Class of Service and how to accommodate the former,

 Briefly explain connectionless and connection-oriented communication modes,

 Identify the steps to communicate voice in packets, and the transmission characteristics which are critical to call quality,

 Trace the flow of a message over an MPLS network using TCP in IP packets,

 Describe Differentiated Services and how to use MPLS labels to implement Diff-Serv,

 Explain how to achieve service integration using MPLS and why you would want to,

 Show how to aggregate traffic using MPLS,

 Explain exactly what is meant by “MPLS service” and why “IP service with an SLA (service level agreement)” would be more accurate, and

 Identify two differences between Internet service and MPLS service, and the pros and cons for each.

Technical Background / Introduction

In the previous course, we used a private network, i.e. dedicated point-to-point circuits connected with routers, as the simplest framework for understanding packets, bandwidth on demand, routers, and network addresses.

A router is a device than relays packets from one circuit to another on a first-come, first-served, packet-by-packet basis. Knowing which circuit to relay the packet to is the routing part of the story, also called packet switching and packet forwarding.

Routers implement bandwidth on demand by not reserving a fraction of the capacity of the connecting circuit for each device (channelizing), but instead giving each device the possibility of using the full capacity of the connecting circuit – when there is something to transmit.

Since devices generate traffic in bursts, and normally have nothing to transmit, many more devices can be connected to the circuit using bandwidth on demand instead of channelizing.

This results in either lower cost or higher bandwidth for each device:

• Implement the same apparent bandwidth as channelizing using a cheaper, lower-speed connecting circuit, or
• Implement higher apparent bandwidth for each device for the same cost as a channelized connecting circuit.

In this course, we will take the same idea and apply it again at the carrier network level: replacing the dedicated lines between customer locations from the simple framework of the previous course with bandwidth on demand service from a carrier between the customer locations.

This brings the same benefit to the customer as it did to individual devices in the previous course: lower cost or faster performance.

All of the carrier's customers in a city are given access to the same high-speed intercity circuits, with the possibility of transmitting to other cities at full line speed – but only when they have something to transmit. This is called a packet network service provided by a carrier.

This type of service is used by businesses (including government, organizations and other carriers) to implement cost-effective, flexible, high-speed packet communications between specific locations.

It is, of course, also the technical fundamentals of the collection of packet networks that are called the Internet.

Course Outline

1. Introduction

Course overview. Concepts of Packet Switching and Bandwidth on Demand.

2. Carrier Packet Network Basics

Provider Edge, Customer Edge, Access and Core

3. Service Level Agreements

Class of Service and Traffic Profile

4. Virtual Circuits

Virtual Circuits, Virtual Circuit IDs, Traffic Classes

5. QoS Requirement for Voice over IP

What is needed for packetized voice to work

6. MPLS

MPLS components, jargon, and basic operation

7. TCP/IP over MPLS

MPLS for VPN or VPLS, Tracing a file download end-end

8. Differentiated Classes of Service (Diff-Serv) using MPLS

Traffic classification, QoS, Diff-Serv: multiple CoS

9. Integration and Convergence using MPLS

All traffic carried on a single network technology

10. Using MPLS Label Stacking to Manage Aggregates of Traffic

Layering virtual circuits on virtual circuits for access and core

11. MPLS Services vs. Internet Service

Pros and cons, similarities and differences. The Future.

Detailed Course Description

Lesson 1. Course Introduction

The first lesson reviews the concepts of bandwidth on demand and packet switching, then gives an overview of the course objectives, the topics to be covered and a description of each lesson. It is available for free on teracomtraining.com and serves both as a course overview and a quality sample of the graphics, text and presentation.

Lesson 2. Carrier Packet Network Basics

This lesson cover the foundational concepts of packet switching and overbooking or bandwidth-on-demand, the physical components of a carrier packet network service such as Customer Edge, Provider Edge, types of access circuits and the network core plus why PE equipment is deployed at the customer premise in some cases. This lesson finishes with a summary of the benefits of packet services versus dedicated lines and circuit-switched connections.

Lesson 3. Service Level Agreements: Traffic Profile and Class of Service

This lesson describes how performance is managed, that is specified, measured, guaranteed and controlled, on a bandwidth-on-demand network which is overbooked – the Service Level Agreement which guarantees specified network transmission characteristics, called a Class of Service, based on the condition that the customer remains within a defined traffic profile, plus how out-of-profile traffic is handled.

Lesson 4. Virtual Circuits

In this lesson, we cover the fundamentals of virtual circuits which are an essential component of all packet communication networks. We cover the concepts of virtual circuits, virtual circuit IDs, traffic classes, and the fundamental operations principles which are the same for all technologies, including MPLS, and how using virtual circuits is a powerful traffic management tool.

Lesson 5. QoS Requirement for Voice Over IP

Packet network services were initially designed for datacom. Here, we learn how voice is packetized, transmitted over a packet network and reconstructed at the far end – plus the transmission characteristics required for voice quality.

Lesson 6. MPLS

IP has emerged as the packets standard to carry all traffic. Additional protocols to enable traffic management and prioritization are necessary to implement virtual circuits since IP is a connectionless network service. The choice for IP is MPLS (Multi-Protocol Label Switching). The concepts are the same as other virtual circuit technologies X.25, ATM and Frame Relay … but the jargon has changed. We begin by identifying MPLS components, basic principles of operation and jargon.

Lesson 7. TCP/IP over MPLS

In this lesson, we again trace the path of a file downloaded from a server to a client, but over an MPLS network this time, which reveals a significant advantage of MPLS-based network services over Frame Relay implemented in the user-network interface. We also discuss the “Multi” in MPLS, noting how MPLS can, in addition to IP packets, carry frames for VPLS.

Lesson 8. Differentiated Classes of Service using MPLS

Here, we examine how the classification of traffic and the mapping of classes onto virtual circuits creates a Quality of Service mechanism to implement different Classes of Service on the same packet network. This is referred to as Diff-Serv or differentiated services, i.e. providing different Classes of Service for each application: IPTV, VoIP, email, web surfing and others.

Lesson 9. Integration and Convergence using MPLS

In this lesson, we show how virtual circuits and traffic classification are used to combine all types of communications for a business or organization onto the same access circuit which is sometimes called convergence, although service integration would be a more accurate term. This results in a significant cost savings compared to implementing access circuits for each type of communications.

Lesson 10. Managing Aggregates of Traffic with Label Stacking

Here, we learn that MPLS labels can be stacked creating virtual circuits carried over virtual circuits to implement traffic aggregation for both routing and prioritization – both on access circuits in the network core.

Lesson 11. MPLS Services vs. Internet or SD-WAN Service

We complete the course with a review of terminology used for sales and marketing of MPLS, and what that translates to in reality. We use a question-and-answer format quiz to understand the difference between an Internet service, which could be called an SD-WAN, and “MPLS service” described in a sales brochures … and what an “MPLS service” is exactly.