如圖4所示,A/B/C/D/E/F組成的鏈網(wǎng),開通了5個(gè)波長(zhǎng):波長(zhǎng)1是A-C的業(yè)務(wù),波長(zhǎng)2是A-E的業(yè)務(wù),波長(zhǎng)3是B-E的業(yè)務(wù),波長(zhǎng)4是C-F的業(yè)務(wù),波長(zhǎng)5是A-F的業(yè)務(wù),在A掛了一個(gè)網(wǎng)管,在網(wǎng)上發(fā)現(xiàn)F站點(diǎn)收A站方向第5波的OTUR上有B1大誤碼,問如何判斷并定位故障?