Administration Guide
Page 238
... the phone is set to have rolling lines or a wavy pattern, it might not be interacting with certain types of older fluorescent lights in the switch console log: HALF_DUX_COLLISION_EXCEED_T HRESHOLD To resolve this problem, re-enable the port from the switch. 9-18 Cisco Unified IP Phone 7906G and 7911G for Cisco Unified Communications Manager 6.0 OL11954-01 Dual-Tone...
... the phone is set to have rolling lines or a wavy pattern, it might not be interacting with certain types of older fluorescent lights in the switch console log: HALF_DUX_COLLISION_EXCEED_T HRESHOLD To resolve this problem, re-enable the port from the switch. 9-18 Cisco Unified IP Phone 7906G and 7911G for Cisco Unified Communications Manager 6.0 OL11954-01 Dual-Tone...