Test pattern used for locally initiated remote loopback. Valid only if a remote loopback was last performed. Following patterns valid for T1 or Switched 56k CSU/DSU: noPattern - no specific pattern is used, data provided by the DTE. Used to loopback transmit data. Following patterns only valid for T1 CSU/DSU: patternQRW - Quasi-Random Word pattern. Specifically used to measure Bit Error Rates. pattern0In1 - repeated binary pattern of '0' or all zeros. Typically used for verification of B8ZS optioning of the T1 facility. pattern1In1 - repeated binary pattern of '1' or all ones. Typically used for signal power measurements. pattern1In2 - repeated binary pattern of '01'. Typically used in testing for bridge taps. pattern1In3 - repeated binary pattern of '001'. Typically used to terminate a remote loopback. pattern1In5 - repeated binary pattern of '00001'. Typically used to put the remote unit in loopback. pattern1In8 - repeated binary pattern of '00000001'. Typically used to stress the timing recovery circuits of repeaters and other intermediate equipment. pattern3In24 - repeated binary pattern of '000000000000000000000111' or hex '000007'. Typically used to test for one's density (consecutive zeros) tolerance on AMI lines. patternUser - user defined pattern. Following patterns only valid for Switched 56k CSU/DSU: pattern2047 - 2047 bit long pseudorandom pattern containing a maximum of 10 sequential zeros and 11 sequential ones. pattern511 - 511 bit long pseudorandom pattern containing a maximum of 8 sequential zeros and 9 sequential ones. patternStressDDS1 - DDS Stress test pattern #1. patternStressDDS2 - DDS Stress test pattern #2. patternStressDDS3 - DDS Stress test pattern #3. patternStressDDS4 - DDS Stress test pattern #4.