Article DetailsA Guide to IP Phone Technology Part One |
| Date Added: March 19, 2009 01:23:49 PM |
| Category: VOIP |
| Perhaps it would be best to start this guide with an explanation as to what an IP phone actually is. Essentially, they are telephones that use VoIP (Voice over IP) technology rather than the traditional PSTN (Public Switched Telephone System). It should be mentioned however that there are telephones available that are able to use both technologies giving the freedom to use a regular phone line and VoIP. IP phones use certain protocols in order to send and receive information such as SIP (Session Initiation Protocol), or SCCP (Skinny Client Control Protocol). There are also some popular VoIP service providers, of which maybe the best known of course is Skype. Both SIP and SCCP are effective methods of VoIP data transfer but SCCP is part of Cisco Systems and is used as a way for Skinny clients and Cisco Call Mangers phones such as the Cisco CP-7940 to communicate. In terms of hardware, IP phones in many cases look just like a regular telephone. As well as the components or feature, we would normally expect such as keypads, speakers and microphones we may well also find some form of caller ID or messaging display. IP phones will also contain a GPP (General Purpose Processor) and a DSP (Digital Signal Processor) which control application messages and RTP (Real Time Transfer Protocol) delivery respectively. IP phones will also need to house ADC and DAC converters for the conversion of digital data to voice and back again. Ethernet ports or Wi-Fi capability are necessary to enable connection to a network and the internet. Power sources may vary since some IP phones use DC power or batteries where others get their power from the Ethernet. STUN (Simple Traversal of User Datagram Protocol) is used on some types of IP phones that use SIP technology. This is because many firewalls try to block SIP data packets and as such, the Stun client makes it possible for this data to travel across networks from one IP phone to another. Obviously, if there is no firewall between the devices in question, STUN is not needed. IP phones provide a cost effective manner of sending and receiving data such as voice calls and messages. They often have the functionality to provide added features such as conference calling, call transfer and various applications such as news feeds or weather reports. Overall, many IP phones are incredibly feature rich but simple ‘no fuss’ versions can be found too if desired. In part two of this guide we will focus more on some of the different types of IP phones available and what they have to offer. |
