ZyXEL Communications Corporation VMG8924B10A Benutzerhandbuch

Seite von 204
Chapter 21 Voice
VMG8924-B10A User’s Guide
250
Click VoIP > Call History > Call History Incoming Calls. The following screen displays.
Figure 150   
VoIP > Call History > Call History Incoming Calls
Each field is described in the following table.
21.10  Technical Reference
This section contains background material relevant to the VoIP screens.
VoIP 
VoIP is the sending of voice signals over Internet Protocol. This allows you to make phone calls and 
send faxes over the Internet at a fraction of the cost of using the traditional circuit-switched 
telephone network. You can also use servers to run telephone service applications like PBX services 
and voice mail. Internet Telephony Service Provider (ITSP) companies provide VoIP service. 
Circuit-switched telephone networks require 64 kilobits per second (Kbps) in each direction to 
handle a telephone call. VoIP can use advanced voice coding techniques with compression to reduce 
the required bandwidth. 
 SIP
The Session Initiation Protocol (SIP) is an application-layer control (signaling) protocol that handles 
the setting up, altering and tearing down of voice and multimedia sessions over the Internet.
SIP signaling is separate from the media for which it handles sessions. The media that is exchanged 
during the session can use a different path from that of the signaling. SIP handles telephone calls 
and can interface with traditional circuit-switched telephone networks.
SIP Identities
A SIP account uses an identity (sometimes referred to as a SIP address). A complete SIP identity is 
called a SIP URI (Uniform Resource Identifier). A SIP account's URI identifies the SIP account in a 
Table 118   
VoIP > Call History > Call History Incoming
LABEL
DESCRIPTION
Refresh
Click this button to renew the received call list.
Clear All
Click this button to remove all entries from the received call list.
#
This is a read-only index number.
time
This is the date and time when the call was made.
phone port
This is the phone port on which you received the call.
Missed means the call was unanswered.
phone number
This is the SIP number that called you.
duration
This displays how long the call lasted.