According to https://github.com/jackaudio/jack2/blob/6bacf6e1db975e5738821bf4abe20314f5e… typedef enum { NotTriggered, Triggered, Running, Finished, } jack_client_state_t; I don't understand any of jack_client_state_t. I usually see xruns with state = Triggered or Running. I'm incrementally increasing period size of zita-a2j and zita-j2a in order to eliminate xruns.