Possible VoIP Disadvantages That Users Should Be Aware ofByMichael Ventimiglia|January 24, 2013
VoIP services come equipped with tons of features and benefits that range from cost efficiency to greater accessibility. With a long list of positives, some of the services disadvantages are often overlooked. While many of the disadvantages have been addressed by providers, they still continue to surface within the service. Although there are a number of potential and possible solutions, users should still be aware of these factors and the affect they can have on their service.
Reliability: With VoIP, all calls are subject to the limitations of common computer issues. While traditional phone lines typically offer more stability, VoIP phones are susceptible to a number of reliability issues. VoIP is dependent on wall power source. While traditional landline phones run off of power that is provided from the central office, VoIP calls need power from the wall. Though this doesn’t sound too significant of a setback, it can often prove problematic. In the event of a power outage VoIP phones would not work—unless there was a stable power source dedicated. Traditional phone service providers typically have backup generators to keep systems up and running; however, VoIP service does not typically offer this. Additionally, if the ISP (internet service provider) is having problems and connection is not available, users will not be able to place VoIP calls. While most ISP’s are very reliable, this factor should still be considered as it is a distinct possibility. As stated above, backup features do not typically come with VoIP service; however more providers are becoming aware of this and creating some backup capabilities.
In the event that a user’s ISP connection is still operational during a power outage, users would not have the necessary power to their run high speed modem, or any other equipment needed. This would result in users still being unable to reach their VoIP services—again unless there was some type of local backup. With this, many users keep traditional phone lines for emergency use only. While this is practical, it diminishes the cost efficiency benefit of the service.
Another factor to consider is the reliability of the internet connection. Even if there aren’t power outages, inclement weather can still impact ISPs. If users’ internet connections or networks are slowed, VoIP service will lose reliability, as well as quality. Since VoIP uses internet connection, it is susceptible to all the issues associated with home broadband services—i.e. latency, jitter, and packet loss. All of these affect the VoIP service causing calls to be distorted, garbled, or lost. Additionally, VoIP is also vulnerable to issues typically associated with home computers including viruses, worms, and hacking. This, however, is a very rare occurrence, and many VoIP developers are working on encryptions to combat this.
Processor speed can also put VoIP users at a disadvantage. VoIP phone systems are dependent on individual PC’s varying specificities and power. With that, a call can suffer greatly by processor drain. Processor drain can occur when a user, who is using a softphone, opens another program. If the second program opened uses too much of the processor, quality loss will become apparent—your system could even crash.
Emergency Calls: With many VoIP services, 911 services are not always available. In many cases, providers offer e911 services as an alternative. In knowing this, it is very important that users know if emergency calling is included with the provider. A good example of this is Vonage. Vonage supports 911 call routing; however users need to activate this feature first.
As mentioned above many providers offer e911, or enhanced 911 emergency calling. Generally, there are few VoIP providers who offer emergency calling, and if a provider does offer the service, users should address its reliability. There is a great difference to understand in discerning traditional 911 from e911 service. Traditional 911 services allow users to call and connect to the local emergency operator based on an address provided. With e911, the user’s address is provided to the operator electronically, meaning that if the user cannot speak, the address is still provided. While this doesn’t sound like a disadvantage, it can prove to be so.
The address the e911 service provides is the address the user gives when he or she first signs up for the service. So, it is crucial that users keep their provider up to date with location. VoIP uses IP addressed phone numbers. With that, there is no way to assign a geographic location based off of an IP address. So, if the caller is unable to tell the emergency operator his or her address, there is no way to know which emergency center to route the call to. In contrast to this, traditional 911 calls are routed directly to the nearest center based on the address given. As with Vonage, most providers require users to activate/register the feature. In doing this, users register the address that appears when using the e911 service. Also, users are responsible for any changes in address.
Additionally, e911 services are subject to VoIP services’ reliability issues. For example, if there is a power outage the e911 service will not be able to work (along with the rest of the VoIP service). Also, broadband connection, reduced network speeds, and congestion may cause slower service.
Call Quality: Though VoIP offers a ton of features and calling options, the most important factor is the call quality. VoIP calls are vulnerable to a number of different external interferences. For example, the standard phone call operates with a delay less than 10 milliseconds. With VoIP delays can reach up to 400 milliseconds. This results in both callers being unable to hear the other fast enough for conversation to occur smoothly. Though this doesn’t happen on each call, it is a very large problem to be aware of.
Additionally factors such as bandwidth, equipment/hardware, frequencies, weather conditions, jitter, latency, and location all affect the call quality (in addition to the reliability). A lack of bandwidth results in spotty reception. Users must be sure their network(s) provide enough bandwidth to support the service. As with any service, the equipment/hardware used also affects call quality. Poor quality (typically the cheapest) equipment/hardware greatly affects calling as well. Even if users believe they have top of the line equipment, they should research their options to make sure they have the equipment that best suits their needs.
The frequency of a users IP phone can sometimes effect other VoIP equipment. For example, some have experienced problems using 5.8 GHz phones. A good way to go about fixing this problem is by trying a lower frequency (2.4 GHz). As mentioned under reliability, weather conditions can greatly impact call quality. Though there are ways of dealing with other circumstantial factors, weather is not something users can change. Also, the location of VoIP equipment can cause issues too. Some VoIP equipment will interfere with one another when they are located in certain ways. If this occurs, users can try moving their hardware around to eliminate the problem.
Jitter, one of the most common VoIP problems, is also a factor that can cause quality issues. With VoIP information is sent through packets that can travel by different paths from sender to receiver. When packets arrive out of the sent order, the audio will be scrambled. In technical terms, Jitter is the measure of the variability over time of latency across a network. A good way to help decrease Jitter is by using a Jitter Buffer, which temporarily stores arriving packets in order to decrease delay variations.
Latency is also another factor users should consider. Latency, which typically sounds like echo, is the delay between speech leaving the speaker’s mouth and reaching the listener’s ear. This can be due to various delays such as:
Propagation Delay: this accounts for the delays between the speed of light and electrons through fiber or copper—this is almost imperceptible to the human ear, but in conjunction with handling delay, it could cause noticeable loss of quality.
Handling Delay: this occurs when devices forward the frame through the network. While this can affect traditional phone networks, it is a much bigger issue within packet environments.
Queuing Delay: this occurs when packets are held in a queue due to congestion of outbound interface. This delay is greater when the amount of packets is greater than the amount the interface is capable of handling.
Lastly, compression can also decrease call quality. VoIP sends compressed voice data packets. As a result the transmitted load is significantly lighter. This compression software is called codecs. Each codec is assigned a specific use. If they are used for something other than what it is designated for, the quality of the call will suffer.
Security: As with many internet technologies, security is a big concern with VoIP. Though there are many providers developing methods and practices to better manage and implement security in their systems, there are still a variety of threats VoIP users should be aware of. As mentioned under reliability, VoIP is vulnerable to viruses and malware, as well as denial of service, spamming, identity theft, service theft, call tampering, and phishing attacks. While traditional phone calls are unlikely to be intercepted, VoIP calls are transmitted over the Internet, which makes interception (theoretically) possible. Despite this possibility, users should not worry too much, as some traditional phone carriers use the Internet to carry some long distance calls.
As mentioned above, phishing attacks represent a serious threat to VoIP security. They are an attack against data privacy in which the victim gives out his or her personal data after being baited. For example, a data thief sends and email that appears like an official message (i.e. Facebook, your bank, PayPal, eBay, etc.) from a company you have interest (financial or otherwise) in. In the email, a problem will be mentioned that needs your personal data (i.e. credit card, passwords, etc.) to fix. This would be the bait. Users that provide their information are then subject to this attack. This technique is becoming increasingly common, and while there are some techniques to help users avoid this, it is still a common occurrence, and therefore a substantial security risk.
Another good example of a VoIP security issue can be found with Google Voice and privacy theft. The Google Voice service gives you a free number and many features; however, the provider stores your call transcripts in a massive database, which can be indexed on Google’s web searches. Additionally, hackers, government officials, and other third parties can gain access to your personal data as well.
As mentioned above, VoIP comes with a ton of features. While there are a few setbacks inherent in the service, there is no service free of disadvantages. As the VoIP industry continues to grow and expand, new solutions will undoubtedly spring up. While some may wait for this to occur, prospective users should know that the benefits far outweigh the disadvantages.