Thanks for the pointer to the paper! I just had a quick read. The ORTC algorithm passes the tree 3 times and gives the optimal aggregation when no extra routable space is allowed. The table size after aggregation is around 60-70%.
Our level-4 result, however, shows that if extra space is allowed, the table size after aggregation is 30-40%.
It'll be great if you could send us the ORTC code. We're very interested in comparing it with other schemes under the same environment.
Thanks,
--- beichuan
On Nov 11, 2009, at 11:23 AM, Beichuan Zhang wrote: Quick synopsis:
ORTC performs FIB compression such that the number of entries in the compressed FIB is the smallest. However, ORTC requires 3 passes if a tree data structure is used to store the prefixes.
The compression achieved is roughly of the order of what is achieved by level-4b (about 70% on recent tables from routeviews) but no "new" routable space created that was previously unroutable.
On Wed, Nov 11, 2009 at 7:02 AM, Zartash Uzmi <zartash at gmail.com> wrote: I have a working implementation of ORTC and can make it available if needed. The implementation has been tested for routing correctness, on a large number of routeviews tables.
Zartash
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