. Since I'm configuring a 7971G phone, I have eight buttons, of which I'll be using five. Buttons can be configured in a number of interesting ways. Here's the system's output from the button help command: R1-PBX(config-ephone)#button ? LINE button-index:dn-index pairs example 1:2 2:5 Configuration line:button with separator feature options: : normal phone lines example button 1:2 2:5 S silent ring, ringer muted, call waiting beep muted example button 1s2 2s5 b silent ring, ringer muted, call waiting beep not muted example button 1b2 2b5 f feature ring example button 1f2 2f5 see also 'no dnd feature-ring' m monitor line, silent ring, call waiting display suppressed example button 1m2 2m5 see also 'transfer-system full-consult dss' watch line (BLF), watch the phone offhook status via the phone's primary ephone-dn example button 1w2 2w5 o overlay lines, combine multiple lines per physical button example button 102,3,4,5 C overlay call-waiting, combine multiple lines per physical button example button 1c2,3,4,5 see also 'huntstop channel for ephone-dn dual-line expansion/overflow, define additional expansion lines that are used when the primary line for an overlay button is occupied by an active call Expansion works with 'button o' and not with 'button c' example button 4021, 22, 23, 24,25 button 5x4 button 6x4 Small-Office VolP Example Different separator options may be used for each button example button 1:2 2s5 3b7 4f9 5m22 6w10 Not all options are available on all versions of CME. This output is from CME v8.0. Though it may seem daunting, the help display explains most of the options pretty well. I'm only going to use two of them, normal and monitor. Normal lines behave as you'd expect-when a call comes into this line, the phone will ring and the button will light up (assuming the phone has button lights). Where it gets interesting is when you have the same extension configured on two phones. When both phones have simple buttons configured, the line rings on both phones. If the phones have lighted buttons like t