Basic VoIP Overview
Voice over IP (VoIP) allows voice traffic to be transmitted over a data network, such as the public internet or your company data networks. Using VoIP phones, VoIP adaptors, PCs or laptops, it is possible to make telephone calls over the internet and any VoIP enabled private network. Calls can be routed over the most cost effective path eliminating costs of calls between company sites (toll by-pass).
Using an adapter such as an ATA (Analogue Telephone Adapter), an IP Phone, IP PBX (private branch exchange - telephone switch) or PC software you can speak to anyone in the world with a regular phone number on a plain old telephone (POTs) line or on another VoIP enabled device or even a microphone and speaker connected to a PC.
In the past companies have used their own telephone switch (PBX) to switch telephone calls from the Telco provider circuits to the extension number within the site. Each site was connected together with expensive circuits to carry call signals between the PBX devices. The same company may have had a separate network of circuits used to carry the data traffic between the company servers and computers (often terminating in the same buildings). The data circuits were also expensive dedicated circuits for for the data networks. Since the early 1990's equipment has been available to make use of the single set of data circuits to carry voice and data (and now video), computers and routers replace the traditional expensive TDM (time division multiplexor) and analogue PBX switches and vast savings can be made.
The Hardware Approach.....a simple and flexible approach requires the addition of an ATA (Analog Telephone Adapter). An ATA is an analog-to-digital converter which connects your traditional phone to connect to your Internet connection or existing networks. The ATA allows a gradual move to VoIP by using existing telephones and connecting ATAs to allow them to be used on the new VoIP equipment.
Another hardware-based option is an IP phone, which integrates an ATA. An IP Phone is similar in appearance to a standard telephone but includes a built-in adapter. The IP phone connects directly to the switch or router with a standard RJ-45 Ethernet connector. These phones are available in several different standards: MGCP, H.323, SCCP (or skinny), IAX and SIP (Session Initiation Protocol). Each protocol has its benefits and drawbacks and are designed for different applications and sizes of installation.
An IP PBX performs the same functions as the traditional PBX, but makes use of the data network to route traffic. A typical IP PBX will have incoming circuits for Direct Inward Dialing (DID) from the main area telco, interfaces to internal company networks to allow connections to IP Phones, PCs and ATAs, analogue connections to backup PSTN circuits and FAX machines etc. and proprietary connections to existing legacy PBX equipment within the company. ... features can also be combined to allow full integration with the company applications. From menu driven IVR (Interactive Voice Response) to full blown call center applications with intelligent call routing and agent selection etc.....
IP Phones and ATAs are not too expensive; a basic ip phone starts at about $100 with a more complex multi-line ip phone with graphics display about $350 and ATAs start about $80. A traditional PBX costs many thousands of dollars and requires very expensive support contracts and circuit rentals. An IP PBX can cost as little as $1800 and make use of existing data networks.
As the traditional PBX was such a major expense many companies want to continue to use their investment and merge the technologies to permit them to move to VoIP as and when the company is ready. VoIP Consultants can provide the design and implementation skills required.
The Software Approach............. works a little differently.... with the most basic and least expensive software voip solution allowing people with the same installed software to call each other over the Internet. With almost all solution providers these "in-network" calls are for free. Rather than using a telephone, callers use speakers and a microphone connected to their computer or an inexpensive USB phone.
Software-based solutions such as Skype and Vonage etc. are suited for home use and do not adapt to business very well.
ENUM (electronic number) - is one solution to the problem of finding someone's VoIP number in order to route your call the most cost effective way. Enum provides an electronic lookup service (much the same as DNS used for web addressing) so that a telephone number can be checked against an enum list to see if there are any VoIP routes available for that call. In this way a PSTN number can be registered for enum and any calls made to the PSTN number from another VoIP user anywhere in the world, the resulting lookup would provide the VoIP equipment the address of the corresponding VoIP route to that PSTN telephone.
Due to the cost savings aspect and new features , more and more businesses around the world are cutting the landline costs using VoIP solutions. It is very easy to demonstrate the savings to a company with more than three remote offices as they we see obvious savings in calls and circuit costs between their own offices. Even a single office site can benefit from calls routed over the Internet from VoIP customers and suppliers.
Rich features on top of the standard Caller ID, Call Waiting, 3-Way Calling, Voice Mail, email and SMS Forwarding and Standard Call Forwarding such as extension mobility, IVR menu and call center features help present a professional image to the customer.
Callerid pre-selection (calls are routed from the standard PSTN line or VoIP to the department configured to received that call), cost effective routing of outbound calls (any call made is first looked-up on the network to see if the call can be made over the Internet or networks prior to using the expensive PSTN landline), call records and billing information is kept for each user. With hotspots and WiFi more and more available it is now an easy matter to have your own telephone number follow you no matter where you go. Hand sets are available that combine cellphone GSM technology and WiFi technology to allow you to merge your cellphone communications with PSTN and VoIP no matter where you roam. ....... so many options