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E&M Ports
7-15
7.4
E&M port Error Messages
Refer to Appendix B in the System Reference Guide for further information on Error 
Messages regarding this port.
7.4.1
E&M port Troubleshooting
The E&M port may be faulty if a voice signal is not received at one end of a circuit, or if E&M 
signaling is not detected. The following are possible causes:
Faulty receiving CPE at the near end (where the problem was first noticed)
Faulty transmitting CPE at the far (opposite) end
Faulty cabling between the CPE and E&M port at either end
Faulty E&M port at either end
T1 network failure
Improper port configuration at either end (e.g., time slot and/or WAN assignments)
First, verify that the T1 network has not failed. Check for a CGA-Red alarm on the associated 
WAN port at the end where the incoming VF signal loss is first noticed. The CGA indicates 
that the incoming network signal was lost (or that the receiving WAN port is out of frame). 
During the CGA, all voice ports with time slots on that WAN port will also be disabled, and 
the associated far-end WAN port will be in a CGA-Yellow alarm state. If the network is faulty, 
you must clear that trouble to restore your circuits.
If the network is okay, verify that the proper WAN ports and time slots are assigned to the 
associated E&M voice ports at both ends, as previously outlined in this chapter. In a 
point-to-point network, the near-end and far-end E&M ports should both be assigned the same 
WAN port and time slot number. Also make sure the other parameters (such as the transmit 
and receive TLPs) are set properly at both ends.
If the E&M port parameters are correct at both ends, and if the network is okay, the trouble is 
isolated to the E&M port or the associated port. Proceed as follows:
1. At the far end, activate an analog loopback on the E&M port.
2. Send a 0 dBm (digital milliwatt) test signal toward the CPE at that end. That signal will 
be substituted for the normal signal coming from the far-end CPE; it will be sent back to 
the CPE at your end via the loopback path.
3. Check your CPE for this signal. If it is present, the far-end CPE or cabling to the far-end 
E&M port is probably faulty. Disable the loopback and test signal there, and fix the 
problem. If you still don’t receive a signal, go to step 4.