This counter tracks frames belonging to a packet that had undergone segmentation and then failed during reassembly. SAR (segmentation and reassembly) errors point to lost or out-of-order segments arriving for a packet that was split across multiple frames for transmission, a distinct failure mode from single-frame CRC or framing errors since it specifically implicates multi-frame packet reconstruction rather than any one frame's integrity. On a link carrying large packets that routinely get fragmented into several satellite frames, a burst of dropped frames during a brief signal fade would show up here as reassembly failures even if each individual received frame otherwise passed its own CRC check.