Explains how RSVP-TE optimization centralizes path selection to minimize distance, reduce congestion, and improve traffic engineering in networks.
RSVP-TE optimization is a Cisco Crosswork Planning that
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creates explicitly routed LSP paths to optimize route properties such as distance, TE metrics, utilization, and disjointness
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centralizes routing decisions within itself instead of distributing across head-end routers in the network, and
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delivers faster and more predictable performance than the explicit LSP optimization tool.
The main optimization goal is to minimize the path distance, which can be based on TE metrics, delay, or a user-defined value, while not exceeding a bandwidth bound defined for each interface so as to avoid congestion. Unlike RSVP-TE, LSPs are routed even if they cannot avoid exceeding bandwidth bounds for certain interfaces, though these bound violations are minimized. Additionally, you can use this tool for reoptimizing and reconfiguring RSVP-TE LSPs after events, such as network failures and subsequent route reconvergence.
You can specify different treatment for different LSPs: whether the LSPs should be rerouted to shorten the path distance, only as necessary to reduce congestion, or not optimized at all. These three LSP groups are called Opt, Fit, and Fix. Using these input parameters allows for a variety of use cases, such as:
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Global optimization: Minimize the path length of all LSPs subject to specified interface bandwidth constraints.
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New LSP optimization: Minimize the path length of newly created LSPs without exceeding bandwidth bounds specified for the interfaces. Existing LSPs are kept on their current paths, being moved only if necessary to prevent new LSPs from violating bandwidth bound constraints.
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Tactical congestion mitigation: Change the routing of as few LSPs as possible to bring bandwidth on all interfaces below the specified bandwidth bound.
The tool is beneficial for offline planning and configuration of an explicitly routed RSVP-TE network. It is also useful for providing routing decisions for a centralized, reactive network control application, such as the Cisco Crosswork Planning platform.
RSVP-TE optimization tool supports both Inter-Area and Inter-AS functionalities.