This Counter32 counts HDLC receiver buffer overflow conditions on this channel, which occur when frames arrive faster than the CPU can process them. A rising overflow count signals the card's CPU is falling behind on signaling frame processing, which an admin would correlate with overall CPU load (e.g. vismCPUUtilization) to judge whether the card is overloaded. For example, if vismHdlcRcvBufOverflows increases during periods of high vismCPUUtilization, an admin would conclude the card is struggling to keep up with signaling load during peak traffic.