Ip Phone Features and Disadvantages

Common features of IP phones

• Caller ID
• Dialing using name/ID: This is different from dialing from your mobile call register as the user does not need to save a number to a sip phone.
• Locally stored and network-based directories
• Conference and multiparty call
• Call park
• Call transfer and call hold
• Preserving user name/ number when choosing a different service provider (not widely supported).
• Applications like weather report, Attendance in school and offices, Live news etc.

[edit]Disadvantages of IP phones

• Requires internet access to make calls outside the Local area network unless a compatible localPBX is available to handle calls to and from outside lines.
• IP Phones and the routers they connect through usually depend on mains electricity, unlike PSTNphones which are supplied with power from the telephone exchange.
• IP networks, particularly residential internet connections are easily congested. This can cause poorer voice quality or the call to be dropped completely.
• IP Phones, like other network devices can be subjected to Denial of service attacks as well as other attacks especially if the device is given a public IP address^[1]
• Due to the latency induced by protocol overhead they do not work as well on satellite internet and other high-latency internet connections.