Junos Class of Service

Course information
Price: Please Call
Day(s): 2
Course Code: JCOS
Delivery Method: Virtual and Classroom


This two-day course provides students with advanced class-of-service (CoS) knowledge and configuration examples. The course begins with an overview of CoS before going into classification, policing, scheduling, and rewriting. The course then covers class-based forwarding and finishes with a case study. Through demonstrations and hands-on labs, students will gain experience in configuring and verifying Junos CoS features.


To gain the prerequisite skills and knowledge, Juniper strongly recommends the knowledge of the following courses:

  • Junos Operating System (IJOS)
  • Junos Routing Essentials (JRE)
  • Junos Intermediate Routing (JIR)


CoS Overview

  • CoS History and Evolution
  • CoS and DiffServe
  • CoS Fields in Packet Headers
  • CoS Processing

Packet Classification

  • Classification Overview
  • Forwarding Classes and Packet Loss Priority
  • Fixed Classification
  • Multifield Classification
  • Behavior Aggregate Classification


  • Policing Overview
  • Single-Rate Two-Color Policer
  • Tricolor Marking Policers
  • Application—Directly on an Interface
  • Application—Within a Firewall Filter


  • Scheduling Overview
  • Transmission Rate
  • Queue Priority
  • Delay Buffers
  • Drop Profiles and Drop Profile Maps
  • Scheduling Configuration

Hierarchical Scheduling

  • Hierarchical Scheduling Overview
  • Scheduler Modes
  • Hierarchical Scheduling Levels
  • Throughput Example
  • Remaining Traffic
  • Queue Properties in a Hierarchical Scheduling Context
  • Putting It All Together

Rewrite Rules

  • Packet Header Rewrite Overview
  • Rewrite Rules and Tables
  • Rewrite Combinations

CoS-Based Forwarding

  • CBF Overview
  • CBF Configuration

Case Study

  • VOIP Case Study Overview
  • VOIP Case Study: Ingress Node
  • VOIP Case Study: Transit and Egress Nodes

CoS Processing on M Series, T Series, and MX Series Devices:

  • M Series and T Series Architecture
  • M Series and T Series CoS Packet Handling
  • IQ2 PIC CoS Packet Handling
  • MX Series (DPC and MPC/MIC) Architecture and CoS Packet Handling


Upon completing this course, the learner will be able to meet these overall objectives:

  • Understand the history and evolution of CoS.
  • Identify the CoS fields in various packet headers.
  • List the CoS processing stages on devices running the Junos OS.
  • Identify the default CoS settings on devices running the Junos OS.
  • Configure and verify behavior aggregate (BA) and multifield (MF) classification.
  • Configure and verify two-color and tricolor marking policers.
  • Configure and verify schedulers and their components.
  • Configure and verify the multiple levels of hierarchical schedulers.
  • Configure and verify packet header rewriting.
  • Configure and verify class-based forwarding.
  • Create a CoS configuration based on a set of design requirements.

Target Audience

This course is designed for:

  • Individuals responsible for configuring and monitoring devices running the Junos OS, especially those in a service provider environment. It also benefits individuals responsible for designing networks containing devices running the Junos OS.


Recommended preparation for:

  • JN0-660 - Juniper Networks Certified Internet Professional (JNCIP-SP)

Follow on Courses

  • JMR - Junos Multicast Routing
  • AJSPR - Advanced Junos Service Provider Routing

Virtual and Classroom Schedule

The majority of our courses accept V&C delegates, if no dates are found here contact us and we can see if it is possible for the date you require

Dates for all Delivery Methods
Date & Location Language Ver Delivery Method
09 Aug - 10 Aug, 2017
Virtual Training
EN Virtual Learning
08 Nov - 09 Nov, 2017
Virtual Training
EN Virtual Learning
All course dates
Date & Location Language Ver
09 Aug - 10 Aug, 2017
Virtual Training
Virtual and Classroom
14 Sep - 15 Sep, 2017
Virtual Training
Virtual and Classroom
14 Sep - 15 Sep, 2017
Virtual Training
Virtual and Classroom
08 Nov - 09 Nov, 2017
Virtual Training
Virtual and Classroom
07 Dec - 08 Dec, 2017
Virtual Training
Virtual and Classroom

This item has been added to your basket