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This topic describes how to analyze and rectify the CLIP fault.
Symptom
The unified gateway is connected to the PSTN through an AT0 trunk. When a PSTN user makes a call to an intra-office user, the calling number is not displayed.
Possible Causes
The possible causes are as follows:
ϒ⁄The CLIP function is disabled at the carrier side.
ϒ⁄The AT0 trunk line is too long and signal attenuation occurs. As a result, the unified gateway cannot detect analog signal tones.
ϒ⁄The CLIP signal (FSK or DTMF) used at the carrier side is different from that used on the unified gateway.
Parent Topic: AT0 Trunk Faults