Document Organization

This manual is divided into several chapters. The individual chapters describe the software commands and operational mode commands related to a particular software feature. The chapters also provide references for additional information on each feature topic.

This manual contains the following parts and chapters:

• Preface, About This Manual (this chapter), provides a brief description of the contents and organization of this manual and describes how to contact customer support.
• Part 1, "Interfaces and Class of Service," includes chapters that highlight features related to network interfaces, services interfaces, and class of service.

• Chapter 1, "Channelized Intelligent Queuing Interfaces," describes the available types of channelized intelligent queuing (IQ) interfaces (OC-12, DS-3, E1, and STM-1), highlights the differences between the original channelized interfaces and channelized IQ interfaces, and explains special configuration considerations.
• Chapter 2, "Flow Monitoring," describes flow monitoring, explains the differences between passive flow monitoring and active flow monitoring, and provides a detailed list of cflowd record formats and headers.
• Chapter 3, "Source Class Usage," describes source class usage, explains how you can use it to monitor traffic originating from customers, and suggests a variety of ways that source class usage can be incorporated into Layer 3 VPNs or accounting profiles.

• Part 2, "MPLS Applications," includes chapters that highlight features related to Multiprotocol Label Switching (MPLS).

• Chapter 4, "GMPLS," describes Generalized MPLS and explains how you can use it to connect devices at different layers of the OSI layer model.
• Chapter 5, "Connecting IPv6 Islands with IPv4 MPLS," describes how you can tunnel IPv6 traffic across an IPv4 MPLS backbone to connect different customer sites running IPv6.
• Chapter 6, "Multiple Instances for Label Distribution Protocol," describes how you can configure multiple instances of the Label Distribution Protocol (LDP) in a carrier-of-carriers network.
• Chapter 7, "MPLS LSP Link Protection and Node-Link Protection," describes MPLS label-switched path (LSP) link protection and node-link protection, compares them with other protection schemes such as fast reroute, and provides the necessary configuration procedure.
• Chapter 8, "Simplified Interinstance Route Sharing," describes simplified interinstance route sharing and shows how you can use it to simplify the distribution of routes between routing instances.

• Part 3, "Routing Protocols," includes chapters that highlight features related to routing and routing protocols.

• Chapter 9, "Graceful Restart" describes the various forms of graceful restart, explains how MPLS and routing protocols are protected, and provides the configuration procedure for each of the graceful restart-enabled protocols.
• Chapter 10, "Logical Routers," describes the concept of logical routers, explains how you can use them in a network, and shows the steps necessary to implement logical routers within a physical router.
• Chapter 11, "OSPF Version 3 for IPv6," describes how the Open Shortest Path First (OSPF) protocol has been modified to accommodate IPv6 packets.

• Part 4, "VPNs," includes chapters that highlight features related to virtual private networks.

• Chapter 12, "Layer 2 Circuits," describes how you can use Layer 2 circuits as an alternative to Layer 2 VPNs and explains the required protocols and statements necessary to implement Layer 2 circuits.
• Chapter 13, "Multicast over Layer 3 VPNs," describes how you can configure multicast protocols, such as PIM, across a Layer 3 VPN.
• Chapter 14, "Translational Cross-Connect and Layer 2.5 VPNs," describes TCC and Layer 2.5 VPNs, explains how you can connect unlike Layer 2 protocols, and provides suggestions on how you can make use of this special switching capability of M-series and T-series platforms.
• Chapter 15, "Virtual Private LAN Service," describes how VPLS works, explains how it is similar to LAN switching, and describes how you can connect multipoint Ethernet sites across an MPLS backbone.

This manual also contains a complete index. For a list and description of glossary terms, see the JUNOS Internet Software Comprehensive Index and Glossary.