Off-Hook SignalingTrying to get in touch with a co-worker who is busy on a call? UseOff-Hook Signaling to let your co-worker know you're trying to getthrough.There are two types of Off-Hook Signaling: CO Off-Hook Signalingand Intercom Off-Hook Signaling. With CO Off-Hook Signaling, anincoming CO call will send muted ringing to your phone if you are ona handset call or one short burst of tones if on a Handsfree Intercomcall.Intercom Off-Hook Signaling lets you send a signal to a busy exten-sion, then wait for a reply. The signal is one short burst of tones,which comes over the speaker of the busy extension. In addition, theICM key at the busy extension flashes. The busy extension user canchoose not to reply to the signal if it is inconvenient to do so.Signals can be sent manually or automatically. If your system requiresyou to manually send the signal, you simply press a key on the dialpad. The automatic type sends a signal any time you call a busy exten-sion. Intercom Off-Hook Signaling cannot be sent to a busy extensionwhen it is using Handsfree Answerback.You can use other options when you are trying to get through. UseCall Waiting (page 15) to wait in line without hanging up. Or, you canleave a Callback request for a return call (page 22). If you want, sendyour co-worker a Message Waiting indication (page 43). You can alsosend a Selectable Display Message to your busy co-worker, if theyhave a display phone, while they stay on their initial call. They canthen send you a reverse message to your display phone asking you tocall back later, take a message, etc. (page 65).Off-Hook Signaling50