Posts Tagged ‘hierarchical lsp’
In this blog post we are going to review a number of MPLS scaling techniques. Theoretically, the main factors that limit MPLS network growth are:
- IGP Scaling. Route Summarization, which is the core procedure for scaling of all commonly used IGPs does not work well with MPLS LSPs. We’ll discuss the reasons for this and see what solutions are available to deploy MPLS in presence of IGP route summarization.
- Forwarding State growth. Deploying MPLE TE may be challenging in large network as number of tunnels grow like O(N^2) where N is the number of TE endpoints (typically the number of PE routers). While most of the networks are not even near the breaking point, we are still going to review techniques that allow MPLS-TE to scale to very large networks (10th of thousands routers).
- Management Overhead. MPLS requires additional control plane components and therefore is more difficult to manage compared to classic IP networks. This becomes more complicated with the network growth.
The blog post summarizes some recently developed approaches that address the first two of the above mentioned issues. Before we begin, I would like to thank Daniel Ginsburg for introducing me to this topic back in 2007.