This is the device-wide total number of chunks retransmitted across every association on this device. Retransmissions are the clearest device-wide signal of a lossy or congested network path: this number climbing steadily, rather than staying near zero, means signaling traffic is having to be resent, adding latency that can delay call setup or teardown. A jump in this counter coinciding with a spike in WAN link utilization would confirm packet loss on that path is forcing the SCTP stack to resend signaling chunks.