IP Phone Technology Issues - Essay Example

Topic: IP phone Introduction An IP Phone utilizes Voice over IP technology to place and transmit telephone calls through an IP network like the internet rather than using the traditional PSTN used by the analog telephone systems. Digital IP based telephone systems use control protocols like the Session Initiation Protocol and different other proprietary protocols in its functioning. IP phones may be simple softphones that are based on specific software or purpose built hardware devices which have an appearance similar to that of the ordinary telephone or a conventional cordless phone. The traditional analogue phones may be used as IP phones when integrated with analogue telephone adapters. Two interfaces of signal and power wire cables that are combined for common use to necessitate communication between computer networks and IP phones that are separate physical are used; power over Ethernet and USB. Power over Ethernet is favored in places like large-scale call centers or PBX replacements since has some benefits compared to USB. Therefore, numerous industrial users as well as manufacturers of telephone switches that are employed in the building markets for VoIP that ultimately shifts towards more robust PoE technology developed by Siemens and other makers of switches usually see USB as well as softphone PC applications as transitional. Technology issues Software VoIP is an approach and a set of technologies that delivers voice communications as well as multimedia sessions through Internet protocol networks like the internet. Additionally, the phrase internet telephony particularly defines provisioning of communication services including SMS, voice and fax through a public internet instead of the conventional PSTN (Solomon, 2013). The stages and principles employed in the origination of IP calls are the same as those employed in digital telephony and entails signaling, channel set ups, digitizing of analogue voice signals along with encoding. Nonetheless, rather than being transmitted through a circuit switched network, the digital information is put into packets with transmission taking place as packets through a packet switched network. This form of transmission includes carefully considering the management of resources through various time division multiplexing networks. Initially, the providers of Voice over IP service provided business models as well as technological solutions that were similar to the structure of the conventional telephone network. On the other hand, the second-generation providers like Skype have developed closed networks to be used by private users while offering free calls along with convenience. The potentially charge users if they wish to access other communication networks like the PSTN which has restricted the liberty of the users to only mix-and-match third-party components. The third generation providers like Google Hangouts have embraced the idea of federated VoIP, which departs from the structure that is used by the legacy networks. These solutions characteristically enable dynamic interconnection between users on different domains on the internet when they want to place a call to each other. VoIP systems use session control and signaling protocols to regulate signals, set-up as well as tearing down calls and they also carry audial streams through IP connections by encoding audio, video and voice through audio and video codecs like Digital audial through streaming the media. There are different codecs that are used for optimization of media streams based on the requirements of the applications as well as network bandwidth, some aspects depend on narrowband and compressed speech, but others support high fidelity stereo codecs. There are VoIP applications on numerous smartphones, PCs and on devices that access the internet that allows calls and SMS to be sent through 3G or Wi-Fi. DHCP is responsible for assigning IP addresses through a consistent and accurate manner that is similar to the manner in which computers work. Without the IP addresses provided by DHCP, users of IP phones would not be able to get any information they request (Rooney, 2010). A DHCP client can be utilized in the configuration of TCP/IP parameters as well as server details in the event that a network segment employs dynamic IP configurations, further, the DHCP client provides a central and programmed management of the configuration of IP Phones. DHCP has more than one fixed and particular IP address with majority of computers being assigned one that is available from a subnet assigned to a specific network. The IP addresses provided by the DHCP expire since when it assigns an address, it leases that connection identifier to the computer beng used for a particular amount of time with the typical lease lasting five days. Hardware By all measures, the phone is the easiest component of IP telephony to understand and evaluate as it is among the most understood items of technology in the globe. As far as telephones are concerned, everyone understands the basics including how to answer and the protocol associated with its use. In a business environment, most of the likely users do not have an understanding if the common mechanisms involved in using the most advanced aspects like voicemail, transfer of calls, conference calls, holding as well as menu systems among others. All the phones must adhere to these standards while at the same time providing any further functionality that a VoIP system has a capacity to provide. In actual fact, numerous VoIP systems provide most of their functionality through their in-call menus implying that a phone on the desk requires the standard twelve buttons on the dialing pad, a handset to talk into along with a way of plugging it in. However, most phones offer a wide array of additional buttons for controlling options, a display that shows the dialed numbers and the caller ID, a speakerphone with muting capabilities along with volume controls to increase or decrease volumes. These are actually considered as the minimums for a desktop home and any of the newer phone systems. Therefore, the overall hardware looks like a telephone or mobile phone with various hardware components including a speaker and microphone, a touchpad that can be used to enter phone numbers and texts as well as display hardware to provide feedback user inputs and display caller IDs and messages (Wallingford, 2006). They also include a general purpose processor for the processing of application messages, a voice engine or digital signal processor for processing RTP messages, where some IC manufacturers offers GPP and DSP in one chip, and AD and DA converters for converting voice to digital data and digital data to voice. Another component of an IP phone system is an Ethernet or a wireless network for sending and receiving messages on a data network, with most of the IP phones having an Ethernet port for connecting with a PC. This enables computers and phones to use the same data connections that are go through phones to computers. A battery on an AC source usually powers the IP phone but some of them get some electric power from power over Ethernet. Further, some of the IP Phones have an integrated RJ-11 port that allows a connection of the phone to PSTN. Features and weaknesses To begin with, the IP Phone needs an access to the internet in order to make outside the local area network unless a well-matched local private branch exchange exists for handling the calls to and from other lines outside this area. Further, IP phones as well as their routers rely on mains electricity for their power as compared to the PSTN phones that are get their power from the telephone exchange. Nonetheless, this may be mitigated through the installation of a UPS, but the Power over Ethernet interface makes this considerably simple as power may be injected at any connection particularly in the passive mode in cases where all the devices are drawing the same voltage or from the router. This remains the main reason why call VoIP systems used at call centers and PBX depend on PoE entirely making UPS and PoE only valuable if the upstream internet provider also has a dependable power backup installed. Usually, IP networks, especially residential internet connections experience congestions and this may result in poor voice quality or the call being dropped completely. With the incorporation of managed or carrier QoS features by commercial grade routers, this issue has significantly reduced but these features often require to be configured by an expert. Similar to other network devices, IP Phones may be subjected to denial of service attacks along with other attacks particularly if the device has been allocated a public IP address, and this issue becomes more significant for the wireless devices that use 802.11 protocols (Porter, 2006). As a result of the latency that is induced by protocol overhead and other aspects, IP Phones do not work in the same manner on satellite internet, analog cells and other high-latency internet connections while the exceptionally latency sensitive applications like music and control of devices remotely could not exploit the VoIP protocols. Another limitation of the IP phones is that proprietary vendors such as Skype emphasis on the improvement of the quality of calls between their own users in order to increase user base, and this to some level competes and is in conflict with the aim of making connections from Skype to other providers better. The best codecs are usually proprietary and are not licensed to be used by competitors, and this hinders the growth of the industry while at the same time leading to incompatibility. Numerous schemes are in existence with the aim of allowing one internet telephony use to communicate with another completely through the internet and without sustaining the costs associated with a PSTN call. Others are based on SIP addresses while others on proprietary protocols like webcams or internet chat applications. Conclusion An IP phone or application typically has numerous features, which are not supported by an analogue phone including IDs for contacts that are similar to those used for emails, which make them easier to remember compared to phone numbers, as well as easier sharing of the list of contacts to numerous other accounts. In general, the features of IP phones are almost the same as those of Skype and Google Voice, which boast of richer feature sets, but since they depend on the IP support of mainstream operating systems, there are audio problems associated with latency. References Porter, T. (1975). Practical VoIP Security. Rockland: Syngress Pub. Rooney, T. (2010). IP address management. Oxford: Wiley-Blackwell. Solomon, M. (2013). Fundamentals of communications and networking. Jones & Bartlett Learning. Wallingford, T. (2006). VoIP hacks. Sebastopol, CA: OReilly. Read More