This is a mask which indicates which tests from the 'prtSTstCmd' list are allowed for the requested port. If a specific test is allowed, its respective bit will be SET in the mask : TEST BIT local-loop 1 remote-loop 2 loc-and-rem-main-loops 3 remote-analog-loop 4 remote-digital-loop 5 rem-loop-on-ext-unit 6 bert 7 tone-injection 8 dlci local-loop 9 all dlci local-loop 10 dlci remote-loop 11 all dlci remote-loop 12 bert-and-rem-loop-on-rem-unit 13 rem-loop-on-rem-unit 14 block 15 backward-tone-inject 16 llb 17 rlb 18 ft1Enable 21 lbbd 22 lb1 23 lb2 24 llb-on-rem-unit 25 bert-on-rem-unit 26 bert-on-rem-and-llb-on-rem-unit 27 local-and-bert-on-rem-unit 28 local-loop-on-rem-unit 29 localBert 30 test-per-TS 31 e.g : If the return value is 3 -> 0000000000000011 -> Bits 1 & 2 are set -> the allowed tests are : local-loop remote-loop