http://hfboards.hockeysfuture.com/sh...d.php?t=937835
Check out the table in the first post.
Most ECHL teams have one (or more) affiliations with NHL and/or AHL team(s).
There usually isn't a "lower" league team that affiliates with an ECHL team (to provide call ups). But some CHL teams lend players "up" (without any affiliation).