Remote Digital Loopback Testing (At&T6, At&T7); Granting A Digital Loopback Test Request (At&T4); Canceling All Digital Loopback Test Requests (&T5) - 3Com 56K Command Reference Manual

14-6 C 14: T
HAPTER ESTING THE
Remote Digital
Loopback Testing
(AT&T6, AT&T7)
Granting a Digital
Loopback Test
Request (AT&T4)
Canceling All Digital
Loopback Test
Requests (&T5)
C
ONNECTION
The remote digital loopback test, verifies the condition of both devices
and of the phone line. Data flow is shown in the figure below.

 



 


  


Data Flow During Remote Digital Loopback.
The request for and granting of remote digital loopback testing requires
that both devices use ITU-T V.22 standard signaling. If the remote device
does not have the capability or is not set to respond (with
get an ERROR result code.
There are two remote digital loopback options.
If you want to
Send keyboard data to the modem and verify it when it is
returned over the phone lines and to your screen
Have the modem send its internal test pattern and return
an error count to your screen
Example: Sending
AT&T6
returning it over the phone lines and displaying it on your screen.
Using causes the Business Modem to grant a remote device's
AT&T4
request for a remote digital loop-back test.
Using cancels
AT&T5 AT&T4
acknowledge remote digital loopback test requests. This is the default so
that your Business Modem isn't subject to another user calling and tying
up your Business Modem without your permission.




will verify keyboard data sent to the modem by
, and the Business Modem fails to

 



 


  
 
), you will
AT&T4
Command
AT&T6
AT&T7