4-7SONET Configuration4.6 SONET Error Counter DescriptionssonetSectionBIPs The number of Section BIP-8 (Bit InterleavedParity) errors that have been detected since thelast time the port has been reset. The calculatedBIP-8 code is compared with the BIP-8 codeextracted from the B1 byte of the followingframe. Differences indicate that a section level biterror has occurred.sonetSectionLOSs The number of seconds in which Loss Of Signal(LOS) has occurred. A LOS is declared when apattern of all zeros is detected for 20 +/- 3ms.LOS is cleared when two valid framing wordsare detected and during the intervening time noLOS condition is detected.sonetSectionLOFs The number of seconds in which Loss Of Frame(LOF) has occurred. A LOF is declared when anout-of-frame (OOF) condition persists for 3ms.The LOF is cleared when an in-frame conditionpersists for 3ms. While in-frame, the framingbytes (A1, A2) in each frame are comparedagainst the expected pattern. Out of frame isdeclared when four consecutive frames contain-ing one or more framing pattern errors havebeen received.sonetLineBIPs The number of Line BIP-24 (Bit Interleaved Par-ity) errors that have been detected since the lasttime the port has been reset. The calculatedBIP-24 code is based on the line overhead andsynchronous payload envelope (SPE) of theSTS-3c stream. The line BIP-24 code is a bit inter-leaved parity calculation using even parity. Thecalculated code is compared with the BIP-24code extracted from the B2 bytes of the followingframe. Differences indicate that a line layer biterror has occurred.sonetLineFEBEs The number of line Far End Block Errors (FEBE)that have been detected since the last time theport has been reset.
