Consultant Wil Allsopp highlights some of the risks inherent in Voice over Internet Protocol.

During the past few years the two most significant focuses for remaining IT budget have been security and cost saving systems capable of demonstrating rapid ROI. But in almost all areas of business there is a trade off between risk and cost. As companies have double-locked the doors by spending on security for the data network, they may have left the windows open by pursuing saving in areas such as VoIP (Voice over Internet Protocol).

The VoIP ‘revolution’ has been talked of since the 1990’s as the ‘next big thing’ in the enterprise telecoms sector; saving companies vast amounts of money on both call charges and internal network infrastructure and support costs. But just as the VoIP market is finally taking a cautious step towards delivering some of its long-overdue promise, the increasing priority of IT security may force it two steps back.

Recent research, by Secure Test, on the Cisco 7900 series VoIP phones have revealed serious security concerns (Note: Secure Test have independently tested the Cisco 7900 as this is the most widely used enterprise VoIP solution. Similar problems may well exist in other vendors products). With susceptibility to both DoS (denial of service) attacks and interception issues, it is clear that transferring phone systems to an IP network opens them up to many of the same security concerns as Ethernet data networks. More worryingly, phone systems may be harder or even impossible to patch.

Like many IP devices Cisco’s VoIP phones are vulnerable to ARP (Address Resolution Protocol) spoofing, allowing ‘man-in-the-middle’ attacks and including data interception and packet injection. This means that any VoIP phone can be tapped by anyone else with a phone on the same network, any individual VoIP phone can be crashed easily and any VoIP network infrastructure is heavily vulnerable to DoS attacks.

Looking first at the vulnerabilities of VoIP phones to DoS attacks, Secure Test’s initial research has shown that Cisco 7900 series phones, specifically where running the default Skinny (SCCP) protocol for messaging, can be crashed relatively easily using one of several methods. By attaching a PC to the VoIP network it is possible to send malformed messages to a target phone or to cause a buffer overflow on one of several fields resulting in a crash. By performing any of these attacks on the switchboard phone, research demonstrated that it would be relatively trivial for an attacker to disable an entire phone system in minutes.

Further research then went on to show that using a similar DoS attack, a Cisco 1760 VoIP enabled router was also vulnerable. Sending a message of 50,000 characters plus to port 2000 (the TCP port used by the router to communicate with the phones) causes every VoIP phone on the network to reboot or crash, completely disrupting communications.

Given the number of Cisco VoIP implementations in companies where the telephone constitutes a business critical system this vulnerability quite rightly send chills down the spine of many a communications manager, especially as avoiding the problem is difficult. Ideally, Cisco would release a patch to better handle malformed or malicious traffic and recover from network errors. However, whilst Secure Test responsibly informed the vendor of the problems several months ago, as yet, there have been no visible signs of progress. Understandably there may be greater problems in patching ‘dumber’ devices such as telephone hardware, relative to providing security updates for PC’s and servers. But, if the window of exposure cannot be effectively shortened by a company with the development capacity of Cisco, this could be seen as a good argument not to run phones on open IP networks until these problems have been overcome.

Having discovered the vulnerabilities with regard to DoS attacks, tests then moved on to see whether the ARP spoofing attacks, specifically data interception, were possible. Any fan of spy films will know that telephone tapping is perfectly possible on traditional PSTN based phones. Since this usually requires a hardwire tap to be set into the PBX, however, this becomes a question of the physical security of the core infrastructure. Initial tests on VoIP phones, however, have shown that where data is not encrypted, it is relatively easy to intercept, listen-in on or record conversations on any phone, from any other phone point on the network. Worryingly, most of the commonly used VoIP phones do not encrypt traffic by default and currently, many do not even support the necessary protocols to make this possible.

Initial tests on the Cisco 7900 have proved that it is possible to carry out an ARP attack on a target phone which draws the data stream through the attacker’s computer. As any conversation is transmitted in the clear using standard RTP (Real time Transfer Protocol), this can easily be decoded, listened in-on and recombined in real time, leaving the victim(s) none the wiser.

As researchers found it relatively simple to develop a tool to automate this process, it can safely be assumed that such tools are freely available on the Internet. This means that where VoIP handsets do not support the secure RTP protocol necessary to protect traffic (as with all current Cisco phones) it should be assumed that all communications could be intercepted.

All of the attacks outlined above are difficult to guard against as they work using the very essence of convergence; that you do not physically segregate the data network and the phone system. Even where separate IP networks are used, you can simply plug a PC in to the telephone network via the phone port. As one of the major advantages of VoIP is computer telephony integration (ie. screen pop-up with call information and multi-channel CRM systems) most hardware phones contain a built in switch to allow a PC and a phone to occupy the same port.

Looking beyond this, the increased sophistication of an IP based telephone network even makes it easier to create Trojans to carry out these and other attacks remotely. Secure Test most recent studies suggest that once a network has been infected, this makes is perfectly feasible to tap VoIP calls and carry out DoS attacks remotely from outside the company network.

Wil Allsopp is a consultant with Secure Test. Secure Test will be demonstrating VoIP vulnerabilities over Internet Protocols on their stand at Infosecurity Europe 2004, Europe's number one IT Security Exhibition. Now in its 9th year, the show features Europe's most comprehensive FREE education programme, and over 300 exhibitors at the Grand Hall at Olympia from 27th to the 29th April 2004.

As it currently stands, Google’s recent addition of Public Switched Telephone Network voice calling to Gmail is much ado about nothing. While the feature works well enough and Google enjoyed a nice burst of voice traffic right after launch, I can only hope the move is the first step in a more ambitious Unified Communications play, rather than a plan solely to beat Skype or, even worse, yet another Google service thrown against the proverbial wall solely to see where an ad might stick.

Users who look at Skype strictly as a cheap tool may move their voice business to Gmail lbecause it is the cheapest or most convenient alternative. But for others, Skype is more than a phone. It’s a community, isolated in its little walled garden, where contacts both domestic and abroad are reachable for free via voice, video or text. Moving lock, stock and barrel to Gmail means losing access to those contacts.

I fall into the Skype-as-a-tool camp, so I’ve already packed my bags. I was a SkypeOut subscriber for years, but when Skype said it was axing my yearly rate, I got all huffy about it over Twitter, and then passive-aggressively let my subscription lapse when my term ended in August. I needed a new solution, and Google’s works well enough even if I’m forced to swallow massive compromises for the sake of a few free calls.

I was a happy GrandCentral user for the time before Google’s acquisition, but when porting that service to Google Voice, Google forced me to use a new Gmail account since it wouldn’t work in my Google Apps domain. Due to some odd behavior after the transition, the need for a Gmail account I wouldn’t use for anything else and services soon offered by my workplace that made Google Voice redundant, I stopped needing or using Google Voice.

But since the new Gmail voice calling features again only work in Gmail (not Google Apps), and Google integrated my old Google Voice number, it provided a new reason to revisit that dormant Gmail account. The feature works from a browser tab, just like Gmail, although it requires Adobe Flash and Google’s Voice and Video plug-in to make or receive calls. Although the latter can be tricky under certain circumstances to get installed (it’s another AppLocker-unfriendly application from Google), the service works well enough in the few days I’ve spent with it. I can call out from my PC to the PSTN (Public Switched Telephone Network) and mobile phones, and those parties can call me at my Google Voice number, provided I set the service to route calls to Gmail.

But I never built a stable of Skype-only contacts, as I was using SkypeOut for PSTN calls 95 percent of the time. Without SkypeOut, I didn’t need Skype. But for those operating mostly within Skype’s walls, those who have collections of friends, family and associates all over the world whom they talk to and see via Skype, they probably aren’t going anywhere.

So perhaps Google shouldn’t be thinking competition with Skype, but rather thinking about collaborating with them. Instead of luring bandwidth-usurping, low-profit Skype customers to Gmail, perhaps Google could build a massive Skype ConnectZT2e portal on their network, then charge its users a flat-rate fee for calls domestic, international and Skype.

I’ve speculated previously on grander visions for Google to build an interoperability hub for voice and particularly video (in the second half of broad interoperability will be the key to success for Google when it comes to voice and video. And I think Google has coalesced enough pieces such as Gizmo5 and Global IP Solutions to take a stab at something truly interesting.

Competing with Skype for rock bottom Internet voice call pricing–well, that’s not interesting. And not a battle Google needs to wage.

Cisco reportedly is considering buying Skype before the VOIP and video conferencing vendor enters into its planned IPO later this year. It would continue Cisco’s push into video.

Skype officials are in planning stages for their expected IPO, which they announced Aug. 9. But reports are circulating that Cisco Systems may derail those plans by buying the VOIP vendor.

IT blog TechCrunch reported that according to one of our more reliable sources. Cisco officials have made an offer to Skype to buy the company before it completes the IPO process, and that people inside Skype are looking at a $5 billion price tag.

There’s no indication whether Cisco’s initial offer was anywhere close to that figure.

Cisco officials have been vocal about their interest in increasing the companys video communications capabilities. The company sees the potential for a $30 billion communications and collaboration business, with video being a significant part of that space. Executives have predicted that by 2014, video will account for more than 90 percent of all Internet traffic.

Video has been a focus of many of Cisco’s recent acquisitions, including Flip video camera-maker PureDigital last year, the $3.4 billion the company paid for videoconferencing equipment vendor Tandberg, and the proposal Aug. 26 to buy ExtendMedia, which specializes in managing online video content.

Such a deal also would come at an important time for Skype. The company has grown rapidly over the past few year, to the point that it now reportedly has 560 million registered users. However, because most of its services, including video chat, are free, it continues to struggle to make money. Skype officials hope the IPO, which would enable the company to be listed on the NASDAQ, would help turn that around.

However, Skype is not getting some serious competition from Google, which last week announced a VOIP (voice over IP);services that integrates directly into a users Gmail account. Google officials said Aug. 27 that the service had wracked up more than 1 million calls during the first 24 hours of operation.

According to TechCrunch, Google also was interested in acquiring Skype, but backed away due to possible antitrust issues.

It would be left to see whether Cisco could turn Skype into a money-maker, something that eBay coudnt do before selling most of its stake in the business last year.

Company started testing a service that would enable Windows users to conduct a conference call with up to four other people.

In addition, Skype announced Aug. 30 that Skype Connect 1.0, which has launched out of beta, will connect with businesses’ existing UC (unified communications) systems or existing IP-enabled PBX systems.

Using Connect 1.0, business can make outbound calls from desktop phones to traditional landline or mobile phones and be billed at Skypes standard per-minute rate, receive calls from Skype users, and manage Skype calls using existing PBX and UC features, such as voice mail and conferencing.

Since its inception, Skype has been used by many businesses wanting to reduce communications costs, David Gurlé, vice president and general manager of Skype for Business, said in a statement. In fact, based on internal research, in the first quarter of 2010, approximately 37 percent of Skype users reported that they use Skype for some business or business-related purposes.

ortsCisco reportedly is considering buying Skype before the VOIP and video conferencing vendor enters into its planned IPO later this year. It would continue Ciscos push into video.

Google said Sept. 1 Gmail users made more than 10 million calls through its new Call Phones from Gmail feature since it launched a week ago.

The company provided tips on how to use the service with Google Voice.

Aug. 25, Call Phones from Gmail lets users place calls to contacts directly from Gmail. Calls placed from Gmail in the United States and Canada are free and start at 2 cents per minute outside those countries.

The tool, which requires Google's voice and video plug-in, lets users click a Call Phone link. This opens a window with a dialer keypad. Users may began typing the names of their contacts to call, or enter a number and click to dial the contact's mobile phone or landline.

Some of Gmail's 180 million or so users tried out the service, resulting in 1 million calls placed from Gmail in 24 hours.

That pace picked up, with more than 10 million calls lodged in the first seven days since the VOIP tool's release, Google Voice Product Marketing Manager Michael Bolognino said.

Google Voice users using Call Phones from Gmail have their personal Google Voice number displayed as their caller ID, thanks to Gmail's integration with that phone management application.

Bolognino offered tips Google Voice users can employ to set up Gmail to receive calls via their Google Voice number.

Google Voice users may navigate to Google Voice, click on settings and check the box next to Google Chat in their list of forwarding phones.

This will allow Voice users to make and receive calls to their Google Voice number from Gmail and access features such as call screening.

For users who cant place the number they're receiving a call from, users can click the "screen" button and the caller will be sent to voicemail to let the Google Voice user listen to it on the sly.

Google Voice users who pick up a call in Gmail but dont have time to chat at home can hit the asterisk on the Gmail dialer during the call to send the call to their mobile phone.

Users may also press 4 on the Gmail dial pad to record a call, clicking 4 again to record or hang up.

Call Phones from Gmail won't be mistaken for the polish and functionality of Skype's VOIP service, but its early adoption is promising, particularly with the continued integration of Call Phones with the Google Voice phone management application.

With Call Phones from Gmail, Google Voice and the Gmail voice and video chat capabilities it's become increasingly clear Google has a comprehensive VOIP platform on its hands, in practice if not in marketing speak.

Google's latest moves have sufficiently impressed Caris and Company analyst Sandeep Aggarwal, who wrote in an Aug. 26 research note:

We think this is among the top low-hanging non-core search opportunities for Google, besides YouTube, Display, Apps and Mobile Net/Android," Aggarwal wrote.

The global communication industry is $1.4 trillion including voice at $1 trillion. Even if Google just scratches the surface with its new offering, this could be a sizable incremental opportunity.

Indeed, while Google may make some money on international calls, this will be wiped clean in the cost to exchanges who connect these calls wherever they are supported.

Google is likely hammering out new ways to advertise against these services and could possibly add some click-to-call adds for these services in the future.

Vonage has joined the ranks of several providers of Voice over Internet Protocol (VoIP) services. They offer a variety of calling plans that include unlimited calls to the United States and Canada along with low International rates. Many of the features that you are accustomed to with a traditional phone are included in their calling plans. There is a one-time activation fee and you will pay a monthly rate.

Vonage bandwidth

Reviewing any product will yield both positive and negative results. One thing to remember is what affects quality service. Vonage offers an excellent VoIP package the variables include whether-or-not you have high-speed cable and what your bandwidth is set at. If you have poor quality, it could be due to the bandwidth setting. In addition, if there are dropped calls Vonage may not be the one with the problem. Possibly the provider of your Internet service is experiencing complications.

Vonage service

The typical complaint regarding Vonage is the customer service. Many people feel that when they call customer service, the representatives lack courteous responses or does not know the product enough to help them. Those who have extensive computer knowledge rarely have a complaint about the service because they have knowledge to fix any problem that may occur with the service. Those who do not have extensive computer knowledge may find the technical support staff at Vonage of little help, although Vonage is in the process of hiring more support staff. With a bit of patience you will be able to find someone who is capable of assisting you.

The majority of customers are pleased with the rates that Vonage offers on International calls and the calling plans that feature unlimited calling through the United States and Canada, although, several of the customers are not happy with the delays in establishing the VoIP service. Overall, once they have the VoIP calling plan up and running were quite pleased with the amount they saved by combining the phone and Internet expenses.

Vonage router

One of the primary issues that customers have with VoIP services from Vonage is the router that you purchase at the store. It comes bundled with hardware that is very difficult to get working. If you buy the router from the store, be prepared to spend some time setting it up. On the other hand, once it is up and running the service is excellent and the quality and clarity of the calls is outstanding.

Vonage is the leader in the Voice over Internet Protocol (VoIP) phone services. As such, they offer several calling plans to its subscribers. Along with the software and adapters that come with the calling plans, Vonage is introducing WiFi phones and V-phones into the market place. 

Vonage soft phone

If you have ever wanted a phone that fits on your keychain, Vonage has read your mind – V-Phone will turn any computer or laptop into a fully efficient Vonage telephone. The V-Phone comes with Vonage Talk software pre-loaded. There is nothing to install on your computer. You simply insert the V-Phone into any USB port, connect your microphone and headset, and begin making and receiving calls. When you are done, remove the drive and you take your phone and all your information with you. The only thing you need for a Vonage V-Phone is:

*  Vonage Talk Software Pre-loaded
*  Headset With Microphone
*  250mb Usable Portable Memory Storage
*  A Vonage Phone Number

Voip telephones

Vetch IP8100 is a cordless broadband phone that works at 5.8GHz and connects easily to your high-speed Internet connection. It does not require any additional wiring, which makes it perfect to use throughout your home. In addition, it does not require a router! Once you purchase this phone, you plug it to the power supply and your computer and begin making your calls. This phone comes with additional handsets so you can have one in every room of your house. It has a long list of features such as a speakerphone, caller ID, and much more.

WiFi UTStarcom F1000 fits in your pocket and is a wireless VoIP phone. This is a great phone for people who are on the go. Use this phone with any wireless Internet network at either home or traveling and enjoy the money you will save with a Vonage Unlimited calling plan.

Uniden UIP1869V operates with 5.8GHz, provides service through your high-speed Internet connection, and does not need the use of a router. Once you purchase this phone, you simply connect the base station to your computer and plug in the power supply. That is all that is required and you are ready to make and receive calls with your new Vonage VoIP phone. This phone comes with features such as customized ring tones, distinctive rings for each of your address book entries, the ability to store up to 100 address book entries, speakerphone, and much more.

Voip telephony

If you would like to take advantage of the low cost and extra features of VoIP, you may decide to replace your traditional telephone service with a VoIP service. Before cutting the line completely, however, there are a few considerations to keep in mind.

It may not be possible to keep your old telephone umber when you switch to a VoIP service. If the service provider offers local phone numbers in your area, there's a chance that you can keep your old phone number, but there is no guarantee. If this is important to you, check with both your telephone company and the VoIP service provider to make sure you keep your old number.

Having reliable 911 service is another consideration. Some VoIP service providers allow you to register your address in case you need to make an emergency call. This information is used to route the call to the correct emergency call center, but once you are connected the operator will not be able to determine your location if you are unable to speak. If emergency 911 services are necessary for you, you are advised to keep your existing phone line or a cell phone for emergency calls -- at least until this snag has been worked out of the VoIP system.

You may also wish to keep a backup line in case of power outages. VoIP service can be sustained throughout a blackout with the use of battery backups, but during an extended blackout the batteries will probably lose power. If your area experiences a lot of blackouts, it may be a good idea to keep a traditional phone line or a cell phone.

Despite these drawbacks, thousands of people are switching their phone systems over to VoIP. If you wish to follow suit, the first thing to do is to choose a VoIP service provider. There are many to choose from and most offer basic services like call forwarding, call waiting, and call display in their standard monthly fee. The real differences in providers are the rates they charge for long-distance or overseas calls. You should choose a plan which will be the most economical for the type of calling that you do.

Most VoIP service providers offer additional phone numbers in various locations. For example, you could have local phone numbers in several different cities allowing people in those cities to call you at any time for the cost of a local call. If you receive a lot of calls from a certain geographic location, make sure your VoIP service provider can give you a local phone number in that place.

When you sign up with a VoIP service provider they will usually supply an ATA (Analog Telephone Adapter) which allows you to use your old analog telephones with VoIP. If you wish to buy your own equipment such as a router and an IP phone, you can probably get a better rate on the monthly fee charged by the service provider.

The basic equipment that you need for VoIP is a broadband modem (either cable or DSL), a router, and an IP phone. Some units are available which combine modem and router -- these cut down on the amount of equipment necessary. A computer is not necessary but makes it more convenient to access your VoIP account.

Hooking up VoIP is easy -- simply plug the router into the modem and plug the IP phone into the router. There is no need for service calls to get equipment installed.

Since VoIP data is travelling through the Internet the same as any other kind of data, it is vulnerable to the same kind of attacks. There are many software tools available to hackers who wish to retrieve information that is being transmitted over the Internet, and these tools are just as effective with voice data as with any other kind of data.

While this may not be a concern when you are calling your Aunt Mary, it is a big concern for businesses that may routinely use telephone communication for discussing sensitive business information. Due to the increasing popularity of VoIP, security is a big concern and is receiving a lot of attention.

There are a number of points in the transmission of a VoIP call that a hacker can retrieve information from. As well as retrieving actual conversations, hackers could also get information like user identities and VoIP phone numbers. With this information, a hacker can make phone calls with someone else's identity.

Attackers could also record phone calls to listen to conversations and possibly even to restructure voice data to create conversations that never actually existed. Log files could also be accessed and altered.

There are a number of ways these security concerns can be addressed. The first is with encryption that provides the same kind of security as when sending credit card information over a secure data connection. The second is to separate VoIP data from other Internet traffic by using a Virtual Local Area Network (VLAN). Both of these methods can adversely affect call quality, but could be used optionally if the calls are sensitive.

Another security threat that hasn't actually been seen yet is the possibility of sending viruses with VoIP data. Viruses could potentially overload VoIP networks causing delays and reduction in sound quality.

VoIP is not invulnerable to spam either. In fact, there is already a name for it -- SPIT -- Spam over Internet Telephony. This refers to receiving unwanted marketing calls from companies trying to sell services or products.

Is My VoIP Service Secure?

For the individual consumer, VoIP security is mostly a matter of preventing others from eavesdropping on conversations.  Some VoIP service providers offer voice security through the means of encryption or separate data routes. Regular precautions for transferring files always need to be followed. Any data or program that is downloaded should be checked for viruses, and a firewall should be in place for protecting your computer from the Internet.

Hardware VoIP devices, on the other hand, are more vulnerable to attack. Some types of equipment can be rendered unstable or don't even work if they receive certain types of data. Some Internet phones are also susceptible to data piracy, revealing private information under specific conditions.

Businesses in particular need to be concerned about security issues surrounding VoIP. Since many businesses operate their own gateways and other equipment for connecting to the Internet, they are more susceptible to the Denial of Service (DOS) attacks or other kinds of malicious hacking.

Your VoIP equipment includes a broadband modem and an ATA (Analog Telephone Adapter) or IP phone. Both the ATA and the IP phone connect directly to the modem but the ATA allows you to use older analog phones for VoIP. No matter which device you use, it has a unique number associated with it that identifies your current IP (Internet Protocol) address. If you are constantly on the move and connect to the Internet at various locations, your VoIP provider keeps track of your current IP address which allows other people to contact you no matter where you are.

Even if you use your Internet phone from just one location, a VoIP provider is still necessary for most people. The majority of residential Internet connections have 'dynamic' IP addresses -- this means that each time you connect to the Internet you are assigned a new IP address by your service provider.

Even if you have a static IP address (a permanent IP address that never changes) the VoIP provider is useful because people can contact you by entering your username rather than your IP address.

Does this mean you can bypass a VoIP provider and enter IP addresses by yourself? In some cases, the answer is yes. Some hardware does allow you to enter IP addresses manually or with some form of shortcut, but this method is very impractical except for testing purposes. As we mentioned above, most people have dynamic IP addresses, so there is no way to know what the IP address is of a certain person at a certain time unless they first contact you and give you this information and then you initiate a VoIP call before they disconnect from the Internet.

So, VoIP providers are very useful, and they are also very cheap. In fact, most providers offer VoIP connections free of charge. They make money by charging for calls to the PSTN (Public Switched Telephone Network). Most service providers allow you to call any phone number in the world for a relatively low price.

Voip Vendors

Some VoIP providers are Vonage, BroadVoice, Diamond, iConnectHere, Lingo, mywebphone, Packet8, and VoicePulse.  Most of these companies are based in the United States but may also have offices in other parts of the world. For relatively low monthly fees (about $8-$20) they offer unlimited calls in certain geographic areas and offer features like voicemail, call forwarding, and conference calls at no extra charge.

When choosing a VoIP provider, keep in mind the protocol they use. SIP seems to be the emerging standard and offers relatively easy connection routes between various VoIP providers. Other protocols include H.323 and IAX -- these are sometimes offered in addition to SIP. Skype (one of the most popular PC-to-PC VoIP systems) uses a proprietary protocol which means that it is not easy to connect to the Skype network from another VoIP provider. Skype has a service called SkypeIn, however, which allows Skype users to receive incoming calls from PSTN networks.

IP Phone Systems

If you want to use a traditional analog phone set with VoIP you can get an ATA (Analog Telephone Adapter) -- a small box which contains the hardware and software necessary to convert your voice into digital data and send it over the Internet. The ATA has an Ethernet connector and a regular phone plug connector.

The advantage of using an ATA is that you don't have to buy new phones -- just plug in the phone you are currently using, either wired or wireless. An IP phone, however, is more convenient for taking advantage of many of the extra features that are included free with your VoIP account -- call display, call routing, call forwarding, voicemail and many others.  You can still use these features with an ATA, but you may need to configure your VoIP account at the service provider's web site.

There are many IP phones on the market ranging from simple residential phones to complex phone terminals designed for business use. Even basic models, however, have an LCD display for caller ID and phone configuration. More advanced models may have features like speakerphones, headset interfaces, customized rings, and programmable keys which allow you to quickly access certain functions of the phone.

=Do you want to go wireless? Although you can't yet get the freedom of a cellular phone with VoIP, you can still use wireless phones within an IEEE 802.11b wireless network. These phones are suitable for residence, campus and enterprise use.

Besides being cheaper, included in the basic service package are things like call waiting, call display, and call forwarding. You can take advantage of all of these features with an IP phone. When your phone rings, the LCD screen displays the caller information. You can choose to accept the call or redirect it to voicemail or an error message.

Rather than manually routing each individual call, you can set up rules for certain types of calls. For example, anonymous calls could be routed to your voicemail, or calls from someone you wish to avoid could be routed to an error message. Calls can also be forwarded to an outside number. 

Some VoIP services operate the same as traditional phone services. Call waiting, for example, allows you to take a second call if you are already using the phone line. When  another call comes in you hear a short beep and you can switch between the two calls by pushing a button.

If you wish to keep your calls anonymous you can block your caller ID. This way, when you are calling somebody with call display, your name or phone number will not be shown. This feature can be set for all of your calls or just for selected ones. 

If you do not wish to be disturbed, you can route all calls to your voicemail or to a message saying that you are unavailable. With this setting, your phone will not ring until you reset it.

A very handy feature of IP phones is the ability to store names and phone numbers. You can scroll through the phone book or set shortcut keys to commonly called numbers. Every call that comes in can be automatically added to your phone book and you can easily edit or delete numbers at any time.