Leo, On Mar 19, 2013, at 11:57 AM, Leo Bicknell <bickn...@ufp.org> wrote: > In a message written on Tue, Mar 19, 2013 at 11:33:33AM -0700, David Conrad > wrote: >> LISP doesn't replace BGP. It merely adds a layer of indirection so you don't >> have to propagate identity information along with routing topology, allowing >> much greater aggregation. > The problem with LISP is that when the complexity of the entire > system is taken into account it is not signficantly more efficient > than the current system.
When was the last time you (as a network operator) cared about the efficiency of the entire system? LISP (and similar) system are inherently more complex because they're adding a new element to the network -- TANSTAAFL. The point is that the complexity is added at the edge where it is easy/cheap (per node or site). Yes, entire system complexity goes up. However from the perspective of the core where life is fast/expensive, complexity goes down since identity is separated from location. > A LISP network is a similar model, with LISP nodes caching rather than > linecards. You're comparing the equivalent of a DNS lookup with a FIB lookup. Yes, there is a performance hit when you do the mapping of identity to location (TANSTAAFL), however this is at the edge in the millisecond DRAM-stored connection initiation world, not in the core in the nanosecond SRAM-stored packet forwarding world. Regards, -drc
