Specifications

E&M Ports 7-5
CODING
The Coding field sets the PCM companding (coding) method used for a port. Changing the
coding field will apply the coding type selected to all four ports. Generally, the North
American T1 environment uses u-law (mu-law) coding. The coding default setting is defined
by the type of associated WAN port.
LB
The LB setting allows you to loop a port back toward the network and far end for testing and
troubleshooting. Figure 7-2 shows the available loopbacks. The dgtl (digital) loopback sends
the incoming digital signal from the network back toward the far end, without decoding it. The
anlg (analog) loopback sends the decoded analog signal back to the far end. To disable either
loopback after testing, set this field to off.
Figure 7-2. E&M port Loopbacks
PATTRN
The Pattern is the outgoing test pattern to be sent to the selected port by the system. You can
send a different pattern to each port. The none setting disables the test pattern. The D-mW
(Digital milliwatt) option sends a 1 kHz tone at 0.0 dBm. The setting of the Rx TLP field
adjusts the D-mW signal level before sending the signal to the CPE.