VoIP
Voice over IP
Hani Aladmaai
Prof. Ali Bicak
IT-520: Enterprise Infra and Networks

Introduction VoIP or Voice over Internet Protocol is an IP based approach to transmitting voice over a computer network. It allows a person to make voice calls using an Internet connection instead of using a phone line. The user can make phone calls free (in certain circumstances), or they may get a service provider and pay a very low rate. How VoIP works is, it converts your voice into a digital signal that will travel over the Internet. First to send voice over a digital network, it must first be converted to digital and converted back to analog at the receiving end. VoIP may allow you to make a call directly from a computer, via VoIP programs such as Skype, a special VoIP phone, or your traditional phone connected to a special adapter. The research paper will begin with an introduction as to what VoIP is, what it accomplishes, what purpose it serves and how it works; also how it is configured. Next it will discuss some of advantages and disadvantages. Legal issues will also present on the usage of the VoIP.

What is VoIP? VoIP or Voice over Internet Protocol is an IP based approach to transmitting voice over a computer network. It allows a person to make voice calls using an Internet connection instead of using a phone line. The user can make phone calls free (in certain circumstances), or they may get a service provider and pay a very low rate.

How does VoIP work? How VoIP works is, it converts your voice into a digital signal that will travel over the Internet. First to send voice over a digital network, it must first be converted to digital and converted back to analog at the receiving end. VoIP may allow you to make a call directly from a computer, via VoIP programs such as Skype, a special VoIP phone, or your traditional phone connected to a special adapter.

How do you setup VoIP? In order to use VoIP, a broadband connection is required, however you may still use a dial-up connection, but the sound quality may be low. If you would like to use your handset for making VoIP calls, you may get an ATA (Analog Telephone Adapter); this connects the regular landline phone to your computer, therefore turning it into a VoIP phone. There is an alternative to the adapter; it’s an Internet Phone (IP Phone). This is a special phone that works and looks like a regular phone, but the difference is that it connects directly to the internet, so the user does not have to keep his/her computer on all the time in order to receive VoIP calls.

How do you use VoIP? There are a few ways to use VoIP. The first one is through your computer. The user may download VoIP software, e.g. Skype, to start making phone calls; this is an example of making PC to Phone calls. Also with Skype and other VoIP software, it allows the user to make free PC-to-PC calling. Another way to utilize VoIP in your home or business is through broadband phone providers (e.g. Vonage). Broadband phone service enables a person to make phone calls over their high-speed Internet connection. Also depending on the VoIP provider, they may bill you (a low cost) per month.

What are the advantages of VoIP? The greatest benefit of VoIP is that it is very inexpensive. There are many VoIP service providers that offer various calling plans that suit the user’s needs. VoIP can save a person a great deal of money. Another notable advantage of VoIP is mobility. You can take VoIP wherever you go compared to your regular landline which stays in place, whether is at the office or your home. With VoIP you never have to deal with your regular landline telephone company, which makes moving from your old residence to a new, a breeze. All the person must do is take their Internet Phone and adapter or the IP phone with them anywhere they go, and just plug it in a broadband connection and you’re ready to make calls. With smartphones, there is even a greater advantage; the user can connect via Wi-Fi and start using VoIP services such as Skype on their phone.
With VoIP you have greater control of how you use your phone. If you miss a call you have the option to direct the voice mail to your email, you can choose any area code and other features offered at the discretion of the VoIP service.

What are the disadvantages of VoIP? Quality of sound is a disadvantage that many users may experience. VoIP is susceptible to all the mishaps/degradation due to inconsistencies in service associated with home broadband services; which may affect, call quality: latency, jitter, and packet loss. Also the conversation may become distorted, garbled or lost due to transmission errors. VoIP also concerns 911 emergency service problems. The issue is that VoIP is not geographically based therefore leading to problems with connecting to local 911. 911 emergency services were traditionally designed around PSTN telephone network and the method used to provide your home address is built in to your phone system. In the case of VoIP, the emergency service that is contacted is dependent on the local address you provide when you register your VoIP service, so it is important to update your information (address) if you move. There may be Internet Service Provider (ISP) issues. Problems with ISP include: connection is down or unavailable, you will not be able to place calls. Therefore having VoIP as a sole method of telephone communications is a risk. Another disadvantage is power outage, which is a major concern. If power failure occurs your VoIP service will be down, because it relies on power to run. Even if your broadband connection is running, if you have a power outage, you will not have power in any ATAs, routers, or modems you may have. VoIP also has may experience security issues. It is not quite as secure as your regular telephone service. Though rare, it is susceptible to viruses, worms, and other attacks (interception of phone calls). However VoIP developers are working on VoIP encryption to counter this.

What are the legal issues concerning VoIP? Governments are regulating VoIP, in a similar manner to how they regulate PSTN telephone services. Another legal issue concerning VoIP is that there is no clear line of a person’s location when they use VoIP compared to when a person is using a traditional phone system. So for example, when a government agency like the NSA is intercepting communications the location of the user of VoIP will not be clear. Also all interconnected VoIP service providers must meet with requirements similar to traditional phone service providers, according to the Federal Communications Commission (FCC) They must also provide E-911 service; this sends the address (the address registered with your VoIP service provider) of the user in electronic form to the local 911 emergency service in the area. The concern revolving this is that, if your information is not updated, the 911 operator doesn’t have the proper address information.

What are the VoIP types of service providers? There are few types of VoIP services providers in the current world of telecommunication: Residential VoIP, Business VoIP, and PC-Based VoIP services. Residential VoIP uses the Internet connection to place and receive calls. People benefited from this VoIP for saving hundreds of dollars a year. Home phone service with a VoIP company is cheaper than the traditional phone company. Most plans include unlimited local and long distance calling. Instead of using traditional phone lines, VoIP uses high speed Internet, VoIP phones and adapters to work. Usually, voicemail, caller ID with name, call waiting, call forwarding, and 3 way calling systems are free. Unfortunately, they don’t support emergency calls such as 911, and the service can’t function when power outage occurs, and members have to pay monthly fee and the activation fee when they join the system, and some services are not available to the countries where the VoIP services are not significant. The best example for this residential VoIP would be Internet Telephone Provider (ITP), one of the leading VoIP industries in the United States. To remain competitive in any business, companies need to have the best communication. Most of the companies provide PBX phone service that supports any type of business. It links the users among internally with employees and externally with customers. Business VoIP system generally assigned with a unique phone number and the applications such as: auto attendant, virtual extensions; call forwarding, visual voicemail, and online fax service. Incoming and outgoing are remotely controlled via single device. Business VoIP allows the communication with multiple users. Communications in offices are generally at a low cost. Depend on how big the companies are; Business VoIP has a very wide coverage, or even worldwide. However, the voice quality of this VoIP service is generally poor due to inadequate bandwidth use, and business VoIP is not easy to use. The example for this kind of VoIP services are: Vocalocity, OnSIP, Jive PBX, etc. PC-Based VoIP systems have become one of the most common VoIP systems that almost everyone uses today. Software-based services have become available to all other countries, and they are free from downloading, installing, and using as long as the other uses the same system. International communication is very easy, and it reaches to all destinations without any jamming. However, if the caller uses any type of Smartphone devices, they are likely vulnerable to the security threats. The call quality on Softphone is not as good as PCs. The biggest problem for this PC-Based VoIP is that the hardware device is required for the system to operate. The best and the most popular PC-Based VoIP service is Skype, which was founded in 2003 from Denmark and Sweden. The development took place in Estonia, and first version was released on August 2003, and now it is the biggest PC-Based VoIP service in the world.

What is VoIP Circuit Switching v. Packet Switching? Circuit Switching is a basic system that traditional telephone service providers used, but it wasn’t efficient method for connecting calls, and they have been using this for nearly a century. When a call is made between two parties, the connection is maintained for the duration of the call. Circuit is open until the two parties end the conversation. In the earlier telephone history, every call had to penetrate the pipes which they have the ability to send signals to the receiver. For example, if someone who lives in Chicago tries to call his or her mom in Miami, the pipeline has to go through that far distance to make the proper phone call. Due to the far distance, the quality of the voice is not clear, and maintenance would have to fix the pipe once the problem occurs, and takes long period of time. Circuit Switching is very expensive and old. They also have to lend the lines for the far distance call, which implies that the international calls were very expensive before telephone companies switched to Packet Switching system. Traditional Public Switched Telephone Network (PSTN) uses the analog data and circuit switching. Packet Switching is a system that allows the VoIP to carry the useful voice data in form of packets and transmits them one at a time, and to the other end. This means that only useful voice part is transmitted over the Internet and the useless silence part is left out. During a VoIP call, the connection between two parties of a call opens only when a packet is sent or received. This naturally makes for a lot of savings in the bandwidth usage. In this way Packet Switching has a distinct advantage over the traditional telephone connection, which remains open all the time a conversation goes on. It is because of the efficient use of bandwidth resources by packet switching by the VoIP technology that cheap VoIP service is possible. This is the main reason how the VoIP providers can offer various VoIP solutions free, or almost free. Packet Switching has a distinct advantage over the traditional telephone connection, which remains open all the time when a conversation goes on. For example, packet switching uses more network resources in packets, so it is more efficient in connecting with others. Furthermore, when there are too much traffic in the connection, circuit switching would likely to block the connections until the traffic goes out, but packet switching does not have to deal with the traffic, because they use stone-and-forward way in each networking station. Each node takes faster than circuit switching and since the order of packet is linear, detection of error is much easier than circuit switching.

What is the VoIP Call Monitoring? VoIP has both advantages and disadvantages: The main advantage of VoIP is the relatively cheap price and the main disadvantage is quality of call. For businesses who deploy VoIP phone networks -- particularly those who operate call centers -- call quality issues are both inevitable and intolerable. To analyze and fix call quality problem, most of these businesses use a technique called call monitoring on VOIP. VoIP call monitoring, also known as quality monitoring (QM), it uses hardware and software solutions to test, analyze and rate the overall quality of calls made over a VoIP phone. Call monitoring hardware and software uses various mathematical methods to measure the quality of a VoIP call and produce a score. The most common score is called “the mean opinion score (MOS)”. The MOS is calculated on a scale of 1 to 5, although 4.4 are technically the highest possible score on a VoIP network. 3.5 Score is considered a "good call" on MOS. Call monitoring hardware and software analyzes a number of call quality parameters, the most common being, latency, jitter, and packet loss. Latency is the time delay between two ends of a VoIP phone conversation. It can be measured either one-way or round trip. Round-trip latency contributes to the "talk-over effect" experienced during bad VoIP calls, where people end up taking over each other because they think the other person has stopped speaking. Jitter is latency caused by packets arriving late or in the wrong order. Most VoIP networks try to get rid of jitter with something called a jitter buffer that collects packets in small groups puts them in the right order and delivers them to the end user all at once. VoIP callers will notice a jitter of 50ms or more. Packet loss is part of the problem with a jitter buffer is that sometimes it gets overloaded and late-arriving packets get "dropped" or lost. Sometimes the packets will get lost sporadically throughout a conversation “random loss” and sometimes-whole sentences will get dropped “bursty loss”. Packet loss is measured as a percentage of lost packets to received packets. There are two different models of call monitoring these are: active and passive. Active call monitoring occurs before a company deploys its VoIP network. Devices and network specialists that use a company’s VoIP network wholly for testing purposes often do active monitoring. Active testing can't happen when VoIP network is deployed and employees are already using the system. Passive call monitoring analyzes VoIP calls in real-time while they're being used by actual users. Passive call monitoring can sense network traffic issues, buffer overloads and other glitches that network admin can fix them in network down time. Another method for call monitoring is recording VoIP phone calls for later analysis. This type of analysis is not wide used. However, what can be heard during the call, not what's happening on the actual network, this type of monitoring is usually done by human beings, not computers, and is called the quality assurance?

What is the Future of Call Monitoring? The PSTN is still the main method of carrying phone calls and will remain the same for a while, but the time is coming when VoIP will be the standard of calls and replace the PSTN. The standards for VoIP are in an evolutionary state. These standards will allow conference calls from VoIP H/W and S/W phones completely dependable without the need for PSTN. With these improvements coming, VoIP would give customers an IP infrastructure that carries both voice and data fast and reliable. Also, The PSTN provides a limited audio range up to 3 kHz. While using the VoIP for speech CODECs, the range can be extended to 7 kHz, with more audio clarity. With the growth of international users on conference calls, the ease of use of high definition audio will make international calls more productive. With the deployment of additional VoIP conferencing systems world regions, VoIP will be able to serve customers within their region. These regional systems when unified will give the client “local” dialing access, reducing the need for International Free Phone (ITF) numbers. In addition, audio issues will be minimized with the reduction in audio links. Conferences, once started, will be maintained throughout the call. In the event of a failure, the system will pass all of the call details from the non-working to a working resource. The feature will virtually eliminate dropped calls.

What is the VoIP Video Conference? Internet video conferencing has made the world really closed together as it has become such user friendly software with its simplicity. Earlier, video conferencing was projected as useful only for the business as it involved huge cost and it was not meant for individuals and small businessmen. But now, because of the introduction of internet video conferencing, it has become everybody's tool. Online video conferencing works completely on web based technology. This means you don't need any ISDN connection or any specific equipment to do the online meeting. Instead, this being completely online, you need a PC/Laptop, good internet connection, web camera and a microphone. All the settings for video conferencing are ready with this. You just need to create a meeting room using your user id and password and send it to the other participants. They will enter the meeting room with that link. They don't need to buy this software; they can attend the meeting free of cost. This makes meeting very easy and hassle free. Still most of the people are not ready to use video conferencing as they think this it is very costly. They need to buy video conferencing equipment and that should be present on both the sides. They need to install the software and a dedicated person needs to be there to look after the operations as they are not experts in that technology. The advantage with this tool is that this avoids all these things and the major advantage is that it is so cheap that it can be even used by individuals. The two major requirements for VoIP video conferencing these are a camera and sufficient bandwidth. Broadband is a must, meaning a T1 line or equivalent, but a DS3 line is even better if the company plans on doing lots of video conferencing. There are also products available to optimize the network’s IP traffic for data, VoIP and/or VoIP video conferencing as fit. Cameras are relatively inexpensive and increasingly come as standard equipment on both desktop and laptop PCs. Security is only as much a problem with VoIP video conferencing as with any other IP-based communication method, and the solutions are largely the same. Encryption, communication through the Secure Sockets Layer and VPNs (virtual private networks) are all ways of limiting who can participate in or overhear a video conference stream. Some VoIP video conferencing products automatically ensure security at the application level, for example Skype and WebEx encryption. Application developers have made it easy and convenient to start a video conference, generally by choosing from a contact list and sending participants a message inviting them to sign in to the conference. This contrasts with traditional PSTN-based conference-calling and video-conference products, which use pricey dedicated lines and usually must be set up ahead of time. This approach might be worthwhile for large companies that need to broadcast to hundreds or thousands of people at once, but smaller businesses that prize spontaneity and flexibility over reach can choose from dozens of free or low-cost services.

What is the Future of VoIP? Individuals, small businesses, and even large corporations need technology that is both flexible enough to meet the demands of everyday needs, and affordable as well. VoIP technology brings this affordability and flexibility to long-distance phone calls, conferencing, email, and other communication needs. As new possibilities are opened and improvements are offered to customers, there are only positive benefits to VoIP technology. Initially, people were hesitant to accept this new technology. VoIP seemed in many ways to be too good to be true. VoIP technology today seems to be quite secure and well established. VoIP has made advancements in different areas. For example, making long-distance calls around the world for little or no money at one time seemed unheard of. SIP (Session Initiation Protocol) is now part of VoIP reality. SIP is responsible for handling client requests and retrieving server requests. SIP more efficiently manages communication sessions, and call transfers and terminations. Users can easily initiate and receive communication from just about anywhere. Networks are able to correctly identify the user, no matter their location. VoIP technology’s future can be seen as a positive, forward moving future. Not too long ago, Cisco unveiled a VoIP telephone that featured a color, touch screen. Both small and large businesses now had access to a new level of VoIP technology; the phone was user friendly and quite easy to use. Cisco definitely seems to be the leader in the advancement of VoIP technology. Cisco has sold millions of their VoIP capable handsets, more than all their competitors combined. There are however some companies not too far behind, live Avaya for example. Avaya seems determined as well to be a part of the VoIP future. Regardless of the size of the business or corporation, there are countless numbers of opportunities available in the future for VoIP technology.

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