Hello KSwinnen,
what do you want to do? Here a feature list refering to the lines.
Avaya Menu in the Active Call State
Directory - the directory allows you access to phone numbers stored on the system. As described above.
Consultation Call (Enquiry Call) - allows you to talk to another party while on a call. During a connection another party can be consulted. See Calling for details on making a consultation call.
Transfer - allows you to transfer a call to another caller. For details on transferring a call, see Calling.
Conference - during a call you can create a conference between callers. When selected, it places the current call on hold, then conferences all held calls together. For details on creating a conference, see Calling.
Park - during a call you can park a call. For details on parking a call, see Calling.