Prefixes terminating with end node entries each containing identical
length prefix portions in a single child table are compressed by
replacing the end node entries with one or more compressed single length
(CSL) prefix entries in the child table that contain a bitmap for the
prefix portions for the end node entries. A different type parent table
trie node entry is created for the child table. Where the prefix portions
are of non-zero length, the parent table contains a bitmap indexing the
end node entries. Where the prefix portions are of length zero, the
parent table may optionally contain a bitmap for the prefix portions,
serving as an end node. The number of prefix portions consolidated within
the CSL node entry is based upon the prefix portion length.