Cisco MPLS Tunnel Builder Pro Overview

Features of Tunnel Builder Pro

Using Backup Tunnels to Provide Protection

Benefits of Tunnel Builder Pro

Features from Tunnel Builder

Tunnel Builder Pro User Interface

Tabs

Network Map

Status Message Window

Operating Tips

Cisco MPLS Tunnel Builder Pro Overview

Cisco MPLS Tunnel Builder is a web-based graphical application for configuring and visualizing Multiprotocol Label Switching (MPLS) tunnels. It can also be used for viewing performance statistics using the Service Assurance Agent (S AA) on supported Cisco IOS platforms.

Tunnel Builder Pro adds the capability of recommending Fast Reroute (FRR) backup tunnel placement to guarantee bandwidth protection.

Note Throughout this manual, concepts such as guaranteed bandwidth, load balancing, and so forth, are described in the applicable chapters.

This chapter contains the following sections:

F eatures of Tunnel Builder Pro

Tunnel Builder Pro features include the following:

Manages traffic engineering nodes, links, and tunnels

Configures MPLS Traffic Engineering (TE) tunnels
Configures MPLS TE parameters on TE-enabled links and nodes
Configures primary tunnels as fast reroutable
Configures static routes on TE-enabled nodes
Configures fast reroutable backup tunnels

Recommends backup tunnels that will protect against the failure of the following elements:

Nodes—Routers in the network. In the context of Tunnel Builder Pro, nodes are routers that can be protected by next-next-hop (NNHOP) backup tunnels.
Links—Point-to-point connections between adjacent nodes. In the context of backup tunnels, links are protected by next-hop (NHOP) backup tunnels.

Determines what parts of a network are not currently protected by backup tunnels, and creates detailed reports of why the elements are not protected.
Supports specification of Shared Risk Link Groups (SRLGs), where a particular link can belong to only one SRLG.

U sing Backup Tunnels to Provide Protection

Tunnel Builder Pro provides bandwidth protection for both links and nodes through the use of FRR backup tunnels. A backup tunnel is an MPLS TE tunnel used to protect other (primary) tunnels' traffic when a link or node failure occurs.

There are two types of backup tunnels:

N ext-hop (N HOP)—Protects against link and SRLG failure

N ext-next-hop (N NHOP)—Protects against node failure

Links may or may not be part of an SRLG.

Note If the endpoint of a protected link has a backup tunnel configured that ends three hops away, it is called a next-next-next-hop (NNNH) backup tunnel. That type of backup tunnel is not used by Cisco IOS and it is not considered by the Tunnel Builder Pro algorithm. Tunnel Builder Pro ignores NNNH backup tunnels; it does not issue warning or violation messages.

L ink Protection

Backup tunnels that bypass only a single link of a primary Label Switched Path's (LSPs) path protect LSPs if a link fails by rerouting the LSP's traffic to the next hop (bypassing the failed link). These are referred to as next-hop (N HOP) backup tunnels because they terminate at the next hop of the LSP's path after the point of failure.

To provide link protection, Tunnel Builder Pro uses NHOP backup tunnels for LSPs terminating at the far end of a link. For LSPs terminating beyond that, Tunnel Builder Pro uses the following:

NHOP backup tunnels when only link protection is required
NNHOP backup tunnels when both node and link protection are required

Figure 1-1 illustrates an NHOP backup tunnel.

Figure 1-1: Next-Hop Backup Tunnel

N ode Protection

Tunnel Builder Pro provides node protection for LSPs. Backup tunnels that bypass next-hop nodes along LSPs are called next-next-hop (NNHOP) backup tunnels because they terminate at the node following the next-hop node of the LSPs, thereby bypassing the next-hop node. They protect LSPs by enabling the node upstream of a link or node failure to reroute the LSPs and their traffic around the failure to the next-next-hop.

Figure 1-2 illustrates an NNHOP backup tunnel.

Figure 1-2: Next-Next-Hop Backup Tunnel

Note NHOP and NNHOP backup tunnels are typically activated much faster than the time it takes for signaling to notify the head end of each primary tunnel that an element failure has occurred. When an FRR backup tunnel is activated, it is only used until the head end of each primary tunnel receives notification of a failure and can resignal a new end-to-end path for the primary tunnel.

B enefits of Tunnel Builder Pro

Benefits include the following:

Guarantees bandwidth if a single element fails, with bandwidth sharing between independent failures.
Protects more bandwidth than traditional CSPF-based approaches through the use of a sophisticated backup tunnel placement algorithm.
Protects bandwidth more efficiently than a path protection approach by using an element-based approach based on the Cisco Fast Reroute implementation.
Provides choice of primary tunnel traffic to protect the global pool or the subpool.
Allows you to configure a utilization factor to specify underbooking or overbooking in the event of an element failure.
Reduces need for cumbersome, error-prone command line interface (CLI) configurations.
Adds new primary tunnels or reroutes existing primary tunnels without affecting existing protection.
Recomputes backup tunnels only if the topology changes, not when new primary LSPs are created.
Allows load balancing among backup tunnels.
Provides the ability to quickly check whether an existing set of backup tunnels provide guaranteed bandwidth Fast Reroute protection for elements in the network.

F eatures from Tunnel Builder

Tunnel Builder Pro is an enhancement to Tunnel Builder. Tunnel Builder Version 2.0 has the following features that are also incorporated into Tunnel Builder Pro:

N etwork Map

Tunnel Builder Pro displays a network map on the right side of the browser window. The map displays all nodes and interfaces on which MPLS TE is enabled. It can also display MPLS TE tunnels overlaid on this topology. Both primary and FRR backup tunnels can be displayed.

N ode Management

Tunnel Builder Pro does the following:

Gathers and displays the following configuration information about each node in the network map:

Interfaces on the device (IP address, interface name, TE status, global bandwidth settings, and subpool bandwidth settings)
MPLS TE device ID
Static routes that map traffic onto MPLS TE tunnel interfaces

Allows you to save changes to the configuration information of the device and write the current running configuration into nonvolatile memory.

For more detailed information, see "Viewing and Modifying TE Parameters."

L ink Management

Tunnel Builder Pro does the following:

Gathers and displays TE-related link configuration information about the interfaces for each link in the network map. This information includes attribute bits and bandwidth pool allocation.
Provides timely notification to the user of interface up or interface down events that affect any links in the network map based on the Interface MIB.
Updates link bandwidth allocation information for global pools and subpools.

For more detailed information, see "Viewing and Modifying TE Parameters."

T unnel Management

Tunnel Builder Pro does the following:

Displays configuration information about the MPLS tunnels found in a network map.
Allows you to create, display, modify, and delete primary tunnels.
Allows you to create and display backup tunnels.
Recommends backup tunnels that will support bandwidth protection.
Provides a timely notification of a link up or link down event that affects any tunnels in the network map based on the Interface MIB.

For more detailed information, see "Managing Primary Tunnels."

Tabs for various functions on the left side of the window
Network map on the right side of the window
Status message window on the right side of the window, at the bottom

Tabs

You can interact with the network map using the mouse, and view information about the nodes, links, and tunnels on the network map using the following tabs:

S etup—Use this tab for specifying a "seed" router, the device from which topology information is discovered. You can also choose a mapping style from the Setup tab:

Symmetric—The distance between the nodes is minimized.
Hierarchical—The network hierarchy is emphasized.
Circular—Nodes are placed in clusters, where possible.
Orthogonal—Style is similar in appearance to a schematic diagram.

L inks—Use this tab for setting selected link values and displaying information about the links on the network map.

N odes—Use this tab for setting selected node values and displaying information about the nodes on the network map.

T unnels—Use this tab for adding, modifying, or deleting MPLS tunnels on the network map. The Tunnel Builder Pro application propagates the changes to the network in real time.

D elay/Jitter—Use this tab for measuring performance characteristics between devices.

V iews—Use this tab for selecting an MPLS topology or tunnels only, and for monitoring link and tunnel traps. Links and tunnels can be highlighted on the network map based on the selected metric.

B ackup tunnels—Use this tab to view existing backup tunnels, to protect your network with automatically generated backup tunnels with guaranteed bandwidth, and to check the protection of nodes, links, and SRLGs.

Network Map

For a detailed explanation, see "Network Map", and "Using Tunnel Builder Pro for the First Time."

S tatus Message Window

Click one of the following tabs:

Tunnel Builder Status—Displays informational Tunnel Builder Pro network commands.
Backup Tunnel Status—Displays information about requests to run Tunnel Builder Pro's Backup Route Generation (BRG) algorithm for checking or suggesting backup tunnel placement, and provides the status of backup tunnel creation and deletion.

Note If you scroll so that a message is not displayed, and then a new message is displayed, you cannot read the new message unless you scroll up.