What is call appearance and line appearance in IP phones?

[Christopher Chan]

Detlef Lechner wrote:
> Christopher Chan wrote:
>> Detlef Lechner wrote:
>>   
>>> Hello,
>>>
>>> Synaptic: "Twinkle is a voice over Internet Protocol (VoIP) SIP Phone: A 
>>> softphone for making telephone calls using SIP over an IP network. 
>>> Twinkle supports direct IP phone to IP phone communication or a network 
>>> using a SIP proxy to route your calls. Twinkle provides making basic 
>>> voice calls, and in addition the following features (regardless of the 
>>> services that your VoIP service provider might offer): two call 
>>> appearances (lines), ..."
>>> What is a »call appearance«?  I have found a description but I still 
>>> don't understand what a call appearance is: 
>>>     
>>
>> Two call appearances just means that you can handle two internal phone 
>> lines in the phone system. One of them can be tied to a direct number 
>> from an outside line and the other will be your internal extension. Or 
>> however the phone system is setup. One could be your extension and the 
>> other tied to your voicemail.
>>   
> Thank you for commenting. But I would like to know more exactly, what a 
> call appearance _is_, not only what it _means_.
> 

A call appearance is basically a sip line. Two call appearances means 
you can connect two sip lines. How those lines work, however, depends on 
the configuration on the line provider. The line provider can be an 
internal PBX system or a telco. So, I really should not have said 'phone 
line' when they are really sip lines but that is what a sip line is 
supposed to act as.