Use the LOOP LINE command to initiate loopback testing of X25 lines
 only.  The parameters are optional and can be entered in any order.
 Before beginning loopback testing of an X25 line, use the SET LINE
 command to set the STATE SERVICE and CONTROLLER LOOPBACK parameters
 for internal loopback testing or the STATE SERVICE and CONTROLLER
 NORMAL for all other loopback testing.

 LOOP    LINE line-id        COUNT number
                             LENGTH number
                             WITH
                               MIXED
                               ONES
                               ZEROS

1  –  COUNT

 Specifies the number of blocks to be sent during loopback
 testing over the line. The count must be a decimal
 integer in the range of 1 through 65535. If the parameter is
 omitted, only one block is looped.

2  –  LENGTH

 Specifies the length (in bytes) of the blocks to be sent
 during loopback testing. The length must be a decimal
 integer in the range of 1 through 65535. If the parameter is
 omitted, a block length of 40 bytes is used.

3  –  WITH

 Specifies the type of binary information to be sent during
 testing. Three types of data can be sent:

                 MIXED
                 ONES
                 ZEROS

 If omitted, a combination of ones and zeros (MIXED) is sent.

4  –  Examples

      NCP>LOOP LINE DUP-0

          This command initiates a line-level loopback test over
          X25 line DUP-0.  The software loops one message, 4096 bytes
          in length, with mixed binary information.

      NCP>LOOP LINE DUP-1 COUNT 10 WITH ONES

          This command initiates a line-level loopback test over
          X25 line DUP-1.  The software loops 10 messages, 4096 bytes
          in length, with all binary ones information.