Digital Phone Service

Online communication is not restricted to sending text messages anymore. You can have a telephonic conversation with an online friend through VoIP phones. VoIP means Voice-over-Internet protocol that is a mechanism to transmit voice via Internet or other packet-switched networks. VoIP provider first came into play in 1973 for the ARPANET as a cheap means of carrying both voice and data. VoIP software functions by speech data compression techniques that carry telephony signals as digital audio over IP. VoIP services are availed by both direct inward dialing (DID) and access numbers.

How VoIP software functions

The ability to transmit multiple voice tasks over a single broadband network makes VoIP an inexpensive alternative to the PSTN. For this reason, VoIP services are used for call forwarding, conference calling, automatic redial, and caller ID. VoIP phones are independent of location since it requires only an internet connection for access. In addition, it can happily merge with other online services like video conversation, simultaneous exchange of message or data file with the conversation, audio conferencing, managing address books etc.

With VoIP phones, you will also get some of the advanced telephony facilities like call routing, screen pops, and IVR implementations in far less costing and hassles. The problem of mobility previously restricting VoIP usage is now being solved by (Wi-Fi)-enabled cordless phones that function upon WiMAX technology.

Problems of VoIP implementation  

If you are already smitten by such wide range of possibilities, you must consider the flip side of VoIP services as well. VoIP implementations encounter problems of latency and jitter because sequential ordered delivery is not guaranteed by UDP. As a result, if you face long round-trip propagation delay you must get the IP packets restructured by the receiving node.

Often routing VoIP traffic through firewalls and address translators may prove difficult. You need Private Session Border Controllers to let VoIP calls pass from and between protected networks. VoIP calls pass through the firewalls only after the service provider uses certain protocols to route them through similar NATs.

Other VoIP problems include packet loss and echo. A VoIP provider usually functions by using a pulse-to-tone converter. It tackles with the problems of congestion by tele-traffic engineering technique. Jitters or variations of delay are avoided by storing voice packets in a jitter buffer upon arrival and before producing audio.

Security hazards with VoIP services

Apart from these technical problems, VoIP phones often fall prey to eavesdropping. This is a terrible threat to your privacy as a packet sniffer could interrupt with your VoIP calls and change their entire content. This could result to a number of ill effects like Denial of Service and abrupt discontinuation of your connection. VoIP software is specifically vulnerable to the hackers lying in wait to disrupt network security.

However, this problem can be partially tackled if you can hide your voice data network from the users by limiting access to the virtual local area network. You can also opt for compression to limit the problem of eavesdropping. The other way out is encryption and cryptographic authentication but this is not easily available. What you can actually avail is the patent SRTP and ZRTP protocol from Analog Telephone Adapters (ATAs) and various softphones.

Advantages and disadvantages of VoIP software

The new addition to the advantageous front of VoIP is that it has been molded for mass- market services. This will allow subscribers to use full phone facilities as with any PSTN phone. Under this, you could make regular local locals undistinguished from conventional POTS services. This will allow you to retain your older phone number and enjoying broadband internet facilities from that. On the other hand, you can also make international calls from your landline without any extras charges.

This makes VoIP phones complementary to a PSTN line because it fulfils some of the shortcomings of the latter. However, VoIP services can have their pitfalls too; a power cut would render the VoIP dysfunctional unless you have a UPS backup. Emergency services on VoIP are distributed according to the codes of a VoIP provider and it may not always prove helpful to you. Sometimes you may face problems with your outgoing calls from fax machines, DVR boxes, satellite television receivers and alarm systems.

How VoIP services have been adopted

• VoIP services are regularly availed by telecommunications providers who use IP telephony or IP network. The low-cost factor of the VoIP technology is a big gain for various businesses. By adopting VoIP technology, companies can abstract data easily without having to pay any third party. Carriers also use VoIP phones for international telephone calls. The VoIP software is being considered by many telecommunication companies who want to combine mobile and internet facilities.
• The other form of VoIP is what is commonly known as Radio Over Internet Protocol or RoIP. This has been achieved by connecting repeaters and users with Echolink, IRLP, D-STAR, Dingotel and EQSO. This technology helps Amateur Radio operators to enlarge their repeater networks by planting world over repeaters so that operators can access the system with real ham radios.