Hitachi GR2000 Series - Manual (Page 303)

Maintenance Procedure
GR2K-GA-0015 8-41
Ver. 07-02
(5) Remote Modem Loopback Test for WAN Line (RLB):
The testing can be executed on modem-connected serial lines (V.24, not V.35 or
X.21) by entering the
test interfaces and no test interfaces commands from the
device management terminal.
This test loops back the test frame at the remote modem in support of remote
modem loopback test. For example, to test line No. 0 of NIF No. 1, enter the
command lines as shown below:
> test interfaces nif 1 line 0 remote [CR]
(Wait about 1 minute.)
> no test interfaces nif 1 line 0 [CR]
If “Test Count” is not 0 and either “Send-NG” or “Receive-NG” is not 0, analyze
the result in accordance with (a) Internal Loopback Test for WAN Line
(6) Remote Line Loopback Test for WAN Line:
This test loops back each test frame at the other end device in units of physical
layer frame, thus useful for the fault location at a line failure and for the
checkout after the recovery of such a failure. The testing applies to T1 and
non-multiplexed T3 lines under the following conditions.The other end device
must also support the remote line loopback test.
If a remote loopback test is specified on a non-multiplexed T3 line and the other
end device is other than GR2000, the choice of the loopback test type (line or
payload) is not available from the own device but is determined by the setting of
the other end device. If the other end device is also GR2000, specifying of a
remote line loopback test on a non-multiplexed T3 line takes effect regardless of
the setting of the other end GR2000. To set up the device action for a remote
loopback test request, see the GR2000 Configuration Commands, Vol. 1
line (line
information) ( -remote_loopback ).
The remote line loopback test can be performed by entering the test interfaces and
no test interfaces commands from the device management terminal. For example,
to test line No. 0 of NIF No. 1, enter the command lines as shown below:
> test interfaces nif 1 line 0 remote-line [CR]
(Wait about 1 minute.)
> no test interfaces nif 1 line 0 [CR]
*
Note: The result will appear in a similar manner as (a) internal loopback test for WAN line. Make
sure that “Send-NG” and “Receive-NG” are both 0(normal) and “Test Count” is not 0. If
“Test Count” is 0, confirm the line status using the information of the show interfaces
(serial)
information in GR2000 Operations Commands, Vol. 1.
*
Note: The result will appear in a similar manner as internal loopback test for WAN line (a). Make
sure that “Send-NG” and “Receive-NG” are both 0 (normal) and “Test Count” is not 0. If
“Test Count” is 0, confirm the line status using the show interfaces (T1) and show interfaces
(T3) information of the show interfaces (serial) information in GR2000 Operations
Commands, Vol. 1. If “Test Count” is not 0 and either “Send-NG” or “Receive-NG” is not 0,
analyze the result in accordance with (a) Internal Loopback Test for WAN Line.
Note: The test can be executed only when the frame format is ESF.However, the test cannot be
executed in the following cases. Instead, conduct a remote line inband loopback test.
* Frame format = SF
* Frame format = ESF and data link = AT & T T1 lines in T3 synchronous multiplex lines
are not supported.