Setting this object to a value as detailed further on 
(except 0) will initiate a test on the specific port. 
The test/s requested will be set according to the respective
bit. The value of this object will be a sum of (2**n), where n is
the Bit:
  TEST                          BIT                           VALUE
 -----------                    ---                                              ------
 reserved                        0                                                  1
         PayloadLoop=RLB                 1 (=Remote Loopback)       2
 LineLoop=DIG                    2 (=Digital)                       4
 OtherLoop                       3                                                  8
 InwardLoop=LLB                  4 (=Local Loopback)       16
 BERT                            5                                                 32
 LC                              6                         64
         ToneInjection                           7                                                128
         Inband                                      8                                            256
         BERT Remote     (or E1/T1 RLB)          9                                                512
         Downstream-AIS (or E1/T1 LLB)  10                                               1024
         Upstream-AIS                   11                                               2048
         Rem-Loop-on-Rem-Unit           12                       4096
         MacSwapLoop                    13                       8192
         OamETHLoopback                 14                                          16384
         OamETHLinkTrace                            15                                      32768


 e.g : If the requested value is 20 -> 010100  ->
       Bits 2 & 4 are set -> the requested tests are :
                             LineLoopback=DIG
                             InwardLoopback=LLB
                               
Not all tests combinations are valid.
    For valid test combination, see each product's specification.
    For LRS52, only single test is allowed simultaneously

The terminology and order of the first tests (except BERT) 
is according to the one used for Test Status of DS1 and DS3 standards.
    The notations : RLB, LLB, DIG are the most used in RAD's products, but they 
    can be different. For exact definition see product's spec. 

Setting this object to stop (value=0 ; all bits are 0), 
will stop all the user requested tests running on the 
selected port.

When no test is running on the port, the Get value (test status)
    will be 0.

    PayloadLoop=RLB
      The received signal at this interface is looped
      through the device.  Typically the received signal
      is looped back for retransmission after it has
      passed through the device's framing function.

    LineLoop=DIG
      The received signal at this interface does not
      go through the device (minimum penetration) but
      is looped back out.

    OtherLoop
      Loopbacks that are not defined here.

    InwardLoop=LLB 
      The sent signal at this interface is looped back
      through the device.

    LC
      This loop is applicable only for HSSI interface, towards the router .
    
    ToneInjection
          This loop is applicable for analog voice (like FXS).

    Downstream-AIS        
    E1 AIS signal (all ones) is transmitted in the relevant channel
    toward the STM-1 line.

    Upstream-AIS
    E1 AIS signal (all ones) is generated in the relevant channel
    toward the local received tributary channel output 

    Rem-Loop-on-Rem-Unit 
    Request from far end device to activate remote loopback 
    towards near-end device
    
    MacSwapLoop
      This loop is applicable for ethernet port. Loop is 
          implemented by swapping the MAC addresses of the 
          incoming message.
          
    OamETHLoopback
       Ethernet Loopback is used to verify connectivity of a MEP with a MIP
       or peer MEP(s) (ITU-T Y.1731, Clause 7.2).

    OamETHLinkTrace
       Ethernet Link Trace is an on-demand OAM function which can be used for
       the two following purposes:
       - Adjacent Relation Retrieval
       - Fault Localization
       (ITU-T Y.1731, Clause 7.3).