ends a FEOOF incremented here back to the source Figure 22-3. Far-end out-of-frame errors Additional codes, called far-end alarm and control (FEAC) codes, are also available. They include: DS3 Equipment Failure-Service Affecting (SA) DS3 LOS/HBER DS3 Out-of-Frame DS3 AIS Received DS3 IDLE Received DS3 Equipment Failure-Non Service Affecting (NSA) Common Equipment Failure (NSA) Multiple DS1 LOS/HBER DS1 Equipment Failure (SA) Single DS1 LOS/HBER DS1 Equipment Failure (NSA) FEAC codes are shown in the output of the show controllers command. Clear-Channel DS3 Framing Data links require the full capacity of the DS3 without any individual channels, as shown in Figure 22-4. Framing is still required, and either C-bit or M13 framing can be used to maintain clock synchronization between the two ends. The M12 and M23 steps are not needed, however, nor are the overhead bits introduced by them. These bits are used for pure data. Because there's no multiplexing overhead, the amount of bandwidth available over a clear-channel DS3 is 44.2 Mbps. Chapter 22: DS3 DS1 #01 11011 Channelized DS3 DS1 #01 11011 DS1 #02 10011 DS1#02 10011 DS1 #27 11100 DS1#27-11100 DS1 #28 00101 DS1#28-00101 Clear-Channel DS3 11011 11011 Figure 22-4. Channelized versus clear-channel DS3 When using a DS3 for data links, use C-bit framing to gain the benefits of increased error reporting outlined previously. Line Coding DS-3 links support Alternate Mark Inversion (AMI), Bipolar Three Zero Substitution (B3ZS), and High-Density Bipolar Three (HDB3) line coding. AMI is the same as the AMI used on T1s, discussed in Chapter 21. B3ZS is similar to B8ZS, also discussed in Chapter 21, except that it replaces occurrences of three rather than eight consecutive zeros with a well-known bipolar violation. HDB3 is used primarily in Japan and Europe. The default line coding on Cisco DS3 interfaces is B3ZS. When channelized DS3s are used, the line coding may be AMI, depending on how the circuit was ordered. Usually B3ZS is preferred. Configuring DS3s Recall that there a