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  --for 2B+D
         lb1                    23  --for B1
         lb2                    24  --for B2

 e.g : If the return value is 3 -> 0000000000000011  ->
       Bits 1 & 2 are set -> the allowed tests are :
                                    local-loop
                                    remote-loop