Summary

This chapter was somewhat of a departure from the other chapters in this book. Rather than talking about things like configurations and debugs, this chapter concentrated mostly on scalability. Both tactical and strategic TE deployment methodologies were discussed, with a major focus on the scalability of strategic TE deployment in a full mesh. The scalability of various FRR protection methods (link, node, and path) was also discussed.

It is important to realize that the scalability of a particular TE deployment methodology is not the only reason you pick that methodology. You need to consider all sorts of other factors, including network stability, SLAs and uptime goals, and many other things.

The most important thing you can take away from this chapter is that you have two ways to deploy MPLS TE—strategic and tactical—and that they're both valid. Both methods are being used successfully in networks today.

The same thing applies to protection. Whether you use link protection or node protection, your scalability isn't at risk. Your choice of protection scheme has more to do with what types of problems your network is likely to encounter (link flaps? router outages? both? how often?) and how much time you want to put into applying a backup strategy. You can do things as simple as dynamically placed link protection LSPs whose paths are calculated by the routers doing the protection, or as complicated as bandwidth-aware node protection with LSP paths calculated by an offline tool. It's up to you. Hopefully, this chapter has opened your eyes to some of the possibilities, caveats, and mind-sets involved.