Since my upgrade from Fedora 21 to Fedora 22, (libnice upgraded from 0.1.7 to 0.1.13), I noticed that I cannot establish a symmetric video connection with empathy. Only one peer sees the remote video of the other peer. Reverting just libnice package back to 0.1.7 makes it work, so it seems that something changed, between the two versions. I bisected the problem to commit 57393333, precisely the modifications in priv_update_selected_pair().
Migrated to Phabricator: http://phabricator.freedesktop.org/T116