IP Telephony and VoIP Tutorial

Welcome to the IPitomy tutorial. 

The modules below contain the basics of IP Telephony and VoIP. This tutorial includes information which will help you to decide how to use IP Telephony and VoIP technology in the most advantageous way for your business environment. Reading through the tutorial will allow you to become more familiar with the terminology and technology.

Don’t let the terms confuse you. IP Telephony is the term we use to describe the telecommunications application that provides the PBX services for your business. The IP Telephony application in a business environment is sometimes called an IP PBX. VoIP is the technology that puts voice into packets so it can be used on a Data Network.

Principles of VoIP

VoIP converts voice into data and sends the voice packets over the network. These packets get mixed with other voice and data packets and are reassembled into voice by an endpoint device (telephone). The result is a telephone call. When the network is well designed, the quality is as good as or better than that of the traditional public switched telephone network (PSTN).

IP Telephony and VoIP systems function by using standard protocols to communicate. The major protocols to consider in a business communications system are largely invisible to the users, and most likely result in the same application and quality. The most important consideration with standards is what protocol will provide the richest application and the most interoperability. SIP (Session Initialization Protocol) is the most promising standard and is the most widely adopted. When you utilize SIP based telephones, which adhere to open standards, you secure a great degree of investment protection as the phones can be used with any SIP based IP PBX.

An IP Telephony system consists of several components. There are the endpoints, also known as telephones. These can be either an IP telephone or a soft-phone residing on a PC. The role of an IP telephone is identical to that of a traditional telephone. An IP telephone connects directly to a LAN (local area network) instead of a traditional telephone connection. The soft-phone is a program that runs on your PC while performing all of the same functions of a telephone using your multimedia speakers and microphone (plus video in some instances). In an IP PBX, the endpoints are very intelligent.

To control routing calls to and from endpoints there is an IP PBX. This performs similar functions to a legacy PBX/Key System. The IP PBX is the server that all of the endpoints log into. When a smart endpoint wants to make a call, it tells the IP PBX who they want to communicate with. The IP PBX checks to see if that endpoint is available. If it is logged in and the called party will accept the call, then the call is put through. Many of the features in an IP PBX reside in the endpoint, as opposed to a traditional PBX where the features are housed in the central control unit.

When an IP endpoint requires connection to a phone number on the PSTN, a gateway is required. The endpoint tells the IP PBX that it wants to make a call to a specific number. The call is then routed to a gateway device, where the number gets dialed into the PSTN and the call progresses as a normal telephone call. A traditional PBX/Key System that supports IP Telephony and VoIP is referred to as a converged system. This means that the PBX supports traditional telephones, IP endpoints, IP Telephony and VoIP access to another PBX, remote offsite endpoints or all of the above.

Another IP Telephony and VoIP system configuration is called an infrastructure based system. It is identical to the above converged system except it does not support traditional telephones. All of the control for the infrastructure based system resides on a server in the network and in the IP telephones.

Most business solutions will require connection to the PSTN for the majority of their telephone calls. To connect to the PSTN from your legacy PBX, there is nothing to do since PSTN lines are already connected. To connect to the PSTN from a LAN based IP PBX solution, you must install a gateway. A gateway converts LAN based IP Telephony and VoIP packets to traditional telephone transmission and provides a connection to the PSTN. IPitomy utilizes internal analog and T1 gateway modules to connect to the PSTN.

The equipment for IP Telephony and VoIP varies depending on your application needs. The exact list of equipment will be determined by the specific requirements of your business. IP Telephony and VoIP over the LAN often require some infrastructure changes and add traffic to the LAN. Extending IP Telephony and VoIP calls outside of the LAN to remote users over the Internet or WAN (wide area network) links require additional bandwidth planning.

Installing an IP PBX is fairly straight forward. It is actually less complicated than installing a legacy PBX. Since the IP PBX and your IP telephones are located on your LAN, there is no need for additional wiring. The most important issue will be ensuring that your LAN is well designed and working optimally.

The major advantage to using an IPitomy IP PBX is that it is an all in one solution. All of the features you need to provide a great business application are included in one comprehensive package. The phone system, voice mail, conference bridge, ACD system and music on hold are all included. This design also makes everything much easier to set up, configure and operate. The web based administration features are simple and easy to use.

Advantages of IP Telephony and VoIP
From a purely technical sense, one must consider the way the PSTN currently handles telephone calls. Each call is set up and delivered from a pair of dedicated copper wires from the caller to the called party. This creates a dedicated physical connection for a single call with extremely good quality. The technology is sufficient to carry one call at a time over the pair of dedicated copper wires.

VoIP technology “packetizes” the voice turning it into data packets. These packets are then sent to the network. The same copper wire is now capable of carrying significantly more than one conversation. Now, the device used to send voice is also capable of sending other “packetized” information simultaneously like data, video, and instant messages. Consequently, IP Telephony and VoIP are much more effective at transporting voice. Additionally, they will produce a much richer experience for the user when one considers the enhanced features of IP Telephony like remote users, enhanced conferences, and lower costs.

IP Telephony and VoIP Practicality 

Changing over to a new IP PBX system is a major move. The move will affect your company for years to come. The average PBX system has a useful life of 7 years. The decision you make now will be with you for a long time. It makes the most sense to make the move to an IP PBX sooner rather than later. Continuing to invest in older proprietary technology will just increase the risk that the system will need replacing before the seven year useful life. Investing in an IP PBX system will provide a platform for the future that will support software updates and enhancements well beyond the useful life of legacy technology.

Over time, legacy PBX’s will all be replaced with IP Telephony systems. Be sure to consider the underlying technology. SIP is the standard that the industry has embraced. Keep in mind that open standards SIP based IP telephones are the best investment protection you can have.

Benefits of IP Telephony and VoIP

The primary Benefits of an IP Telephony IP PBX System are:

One Wiring system Instead of separate wiring for telephones and separate wiring for data, all data and voice are on the LAN. There is usually plenty of bandwidth available on a well designed LAN.

Web based administration With an IP Telephony IP PBX, all system administration functions are performed on the network, usually through a browser based administration program. If required, the system can be modified from anywhere.

Leveraging the Internet for telephone calls When calls flow over the Internet, long distance charges are avoided. This is ideal for your remote workers who can stay logged into the office all the time without incurring any additional charges.

Peer to Peer phone calls All calls are Peer to Peer. This is a big advantage over the traditional PSTN. After the call is set up by the IP Telephony server the call flows between the two endpoints. All of the voice or video traffic is direct between the two endpoints reducing the congestion at the server.

Unified Dialing Plan Everyone who is logged into the system is capable of receiving and originating calls. If your employee is at a remote office in Seattle and a call comes into the corporate headquarters in Chicago, the call can be directed to the employee in Seattle just as if that person were in Chicago. Use of the corporate communication resources such as voice mail, automated attendant, and email can be centralized simplifying all support and maintenance.

Remote users All users who are logging into the system are part of the IP PBX. This could be a traveling employee at a hotel with Internet access from a room, a user at lunch with a wireless connection at a café, or one of your employees logged in from home when they are feeling under the weather.

Presence Management IP Telephony and VoIP applications can take advantage of presence management. This is a function of the system that allows your users to set how other users view their presence on the system. Most systems have tremendous flexibility. Your presence can be set as busy, available, off line etc.

Reduced Costs Cost reduction in operating an IP Telephony system covers just about all areas of the business.

Investment Protection IP Telephony and VoIP products (particularly those that are SIP based) offer a high degree of investment protection. Since it is apparent that all communications will be IP based within the next 5 years, it makes good sense to begin the shift toward IP Telephony and VoIP as soon as practical. Investing now in an IP Telephony solution that provides interoperability with the new technologies that are available makes a lot of sense.

IP Telephony and VoIP and Security Opening up your network to the Internet poses some inherent risk. Most LANs have some form of security. This security can put some limitations on IP Telephony and VoIP applications. Most LAN administrators are aware of the vulnerabilities of their network to attack from the outside. IP Telephony and VoIP can operate well in a tight Internet security environment.

Multi-site businesses have most likely established a secure data connection between locations making the introduction of IP Telephony and VoIP an exercise in bandwidth management.

Most successful single site IP Telephony and VoIP deployments only use the Internet to connect remote users to the other users in the system. Use of VPNs (virtual private networks) for remote users is a secure way of connecting all of the users without exposing the network to extreme risk.

IP Telephony and VoIP Quality of Service The voice quality of an IP Telephony and VoIP phone call should be at least as good as what the PSTN can provide. This is true as long as enough bandwidth is available for the call. If bandwidth is somehow constrained, quality of service can be affected. In a condition where adequate bandwidth is not available, the call can begin to degrade in quality not unlike a bad cell phone connection.

Quality of service is controlled in several ways. Calls within your LAN environment should not get degraded if the network is well designed. If you extend your IP Telephony and VoIP calls outside of your LAN over a WAN or out on the Internet, then quality of service does become an issue. Routers and switches are available that can prioritize voice packets to maintain good quality of service. On the Internet, there is really very little that you can control when it comes to bandwidth. In real world experiences, the Internet does seem to be able to provide a good option for IP Telephony and VoIP calls with surprisingly good quality when using broadband connections. Use of a high quality bandwidth provider will provide the best quality management. We will be glad to provide you with the assistance required to design your application.

Getting Started with IP Telephony and VoIP IP Telephony and VoIP systems will provide an advantage to just about any business. There is a lot of information to become familiar with when purchasing a new system. We hope this guide has increased your understanding of how the basic technology may fit into your business application.