Hack58.VoIP Hacks

Hack 58. VoIP Hacks

The Voice over Internet Protocol (VoIP) lets you make phone calls over the Internet for less money than the normal phone system. But VoIP services can sometimes be flaky. Here's a grab bag of hacks for getting more out of your VoIP service.

VoIP technology has been around for several years, but only recently has it begun to take off and be available directly to consumers. With a VoIP service, you pay a monthly fee, just as you do to your normal telephone provider, and you get services such as call waiting, caller ID, and similar features. Typically, VoIP phone plans are less expensive than traditional phone plans, and they're often much less expensive for when you make overseas calls. They also offer low-priced "all-you-can-eat" plans for making phone calls in the U.S. They require that you have a broadband Internet connection such as a DSL modem or cable modem because lower-speed service doesn't have a high enough bandwidth to deliver good enough voice quality.

When you use a VoIP service, you plug a special VoIP phone into your home router, DSL modem, or cable modem via an Ethernet cable.

If you plug the phone into your DSL modem or cable modem, you then plug your PC into a port on your phone via an Ethernet cable so that your PC can also get Internet access.

Calls made over VoIP travel over the Internet, as do any other Internet packets. They are then transferred to the normal phone system via a gateway so that you can call any phone in the world as you would with any telephone. You receive calls in the same way. Someone makes a call on a normal telephone, and that call travels over the normal telephone system, then is sent to a gateway where the call is broken into IP packets and delivered over the Internet to your telephone. With this type of VoIP service, you get your own phone number, just like any phone number. In fact, you might even be able to keep your existing phone number.

There are also software-only VoIP services, in which you don't use any special hardware or equipment. Instead, you download a piece of software and use your PC's speakers and microphone to talk, or else plug a headset into your PC's microphone jack. Generally, these only let you call others who use the same software that you do; in other words, you can't make calls to normal telephones, but can make them to those who also use the same VoIP software you're using. In this scenario, the phone call travels over the Internet. It never actually travels to the normal phone system because the calls aren't made to normal telephones.

These VoIP services are typically free. They don't offer full service plans, and so don't have caller ID, call waiting, and similar features. In fact, instant messenger programs such as AOL Instant Messenger, Yahoo! Messenger, and Windows Messenger let you make calls this way. Some of these services let you make phone calls to regular telephones as well, although for that they charge you a fee. And for now, anyway, you can't receive normal phone calls on them; you can make phone calls only. But that is expected to change.

The best-known full-featured VoIP service that lets you make phone calls to anyone and receive phone calls is Vonage (http://www.vonage.com). It offers a variety of service plansfor example, $14.99 per month for 500 minutes of calls per month to anywhere in the U.S or Canada, or $24.99 per month for unlimited calls per month to anywhere in the U.S. or Canada. All plans include a variety of free services, such as voicemail, caller ID, call waiting, call forwarding, call transfer, and three-way calling. And international calls are as low as 2 cents per minute to London, Paris, Rome, and Hong Kong. A variety of other companies are entering the VoIP market, including ISPs and AT&T. The best-known software-only VoIP service is Skype (http://www.skype.com), which is available for free when you make calls to other Skype users.

But using VoIP can sometimes be a frustrating experience. So, use these hacks to solve some common VoIP woes.

5.11.1. Troubleshoot VoIP Phone/Home Router Problems

Some people have had problems when using Vonage VoIP service with their home routers. Instead of incoming calls being sent to their phones, the calls go directly to voicemail. How you solve this varies from router to router, but here's how to do it with the popular Linksys router line. Other routers should have similar fixes.

You're going to set up your router so that it uses its port forwarding feature to send calls directly to your IP telephone. First, turn off your cable modem or DSL modem, all the computers on your network, your router, and your IP telephone. Then, turn your cable modem or DSL modem and your router back on. Turn on your IP telephone, and make sure that turn it on before turning on any PCs on your network. This will make sure it is given the network's first IP address via DHCP.

Your caller ID service on either your normal telephone or VoIP phone can easily be subject to caller ID spoofing so that the caller ID number you see before you pick up the phone isn't really the person calling you. Normally, in caller ID, whenever someone makes a phone call his Calling Party Number (CPN) is sent along with it. Sent along with the CPN is a privacy flag; if the caller has requested that his number not be shared, the flag tells the phone network to block the CPN from being sent.

But VoIP changes all that. Using the open source Linux-based PBX software Asterisk with certain VoIP providers, someone can change the CPN sent along with his call, making it appear to come from any number he wants. So, keep in mind that increasingly, caller ID is being subject to spoofing and hacks.

Once you've turned on your IP telephone and your PCs, log into the Linksys administrator's setup screen by opening your browser, typing, and pressing Enter. Leave the username blank, and use the password admin and press Enter. (That's the default password for the router; if you've changed it, use the password you've changed it to.)

From the setup screen, choose Advanced Forwarding. You'll come to the port forwarding screen. Set up port forwarding to route these port ranges to your IP telephone. Forward each port to the IP address of your IP phone, such as (The IP address will be the first one assigned by your network.) Set the protocol to UDP. Use the port settings in Table 5-8.

Table 5-8. Port ranges for your IP telephone

Port range


IP address

53 to 53


Your phone's IP address

5060 to 5061


Your phone's IP address

123 to 123


Your phone's IP address

69 to 69


Your phone's IP address

10000 to 20000


Your phone's IP address

Your screen will look like Figure 5-6.

Figure 5-6. Setting up a Linksys router to work with a Vonage IP phone

If you're not sure of your Vonage phone's IP address, it's easy to find out. Take the phone off the hook. The red function button on the top of the phone will light up. Press the illuminated red button and then dial 80#. Your IP address will be displayed.

When you're done, click Apply. The port forwarding will take effect immediately, so your problems should be solved.

5.11.2. Get Your Vonage IP Phone to Work with DSL

The nature of some DSL services cause conflicts with Vonage IP telephones, so when you use DSL, you might not be able to get your IP phone to work. Even if the phone previously worked with a cable modem, when you switch to DSL it might stop working.

The problem is that DSL services often require the use of PPPoE, but if you don't also turn on PPoE in your Vonage phone, the phone won't work. To turn on PPPoE in your Vonage phone, open a web browser in the computer that has the phone connected to it. Go to and press Enter. (That's the default address for configuring Vonage phones. If you have another type of phone, or if your Vonage phone has a different configuration address, use that instead.)

The phone's Basic Configuration screen will appear. Select the Enable PPPoE option, and type the DSL service name, username, and password that your DSL provider gave to you. Click Save Changes. You'll get the message "This will require a reboot of the unit. Are you sure?" Click OK. Your phone will reboot. Wait five minutes, and pick up your phone. It will now work.

Is VoIP a Telephone or Internet Service?

When you use VoIP, are you making a phone call or using the Internet? The logical answer, of course, is both. But state and federal governments are not logical, so that question makes an enormous difference in how VoIP services will be regulated. If VoIP is treated as if it were a telephone service, for example, VoIP companies could be required to provide Enhanced 911 emergency phone services and pay into federal and state universal service funds that are used to help pay for telecommunications service to low-income areas, schools, and libraries. Also unclear is whether VoIP services must comply with federal wiretap laws.

At the time of this writing, the Federal Communications Commission hasn't made a definitive decision on the matter, but it has made a series of rulings related to VoIP. It ruled that software-only VoIP that makes PC-to-PC phone calls only is not a phone service and therefore does not have to comply with phone service regulation. It also ruled that state governments do not have regulatory authority over VoIP services that use the telephone system to let you make and receive phone calls to anyone, anywhere, as a phone service. Instead, the federal government has that authority. But as of this writing, it still hasn't ruled on whether it will treat that service like a telephone call, like Internet access, like some hybrid of the two, or in some other way.

5.11.3. Cut Your DSL Costs with VoIP

Many DSL services let you make phone calls as well as get high-speed Internet access over the same telephone line. So, if you use VoIP in concert with DSL, you're paying double for your phone serviceonce for DSL, and the second time for VoIP.

There's a solution: get a DSL service that offers only Internet access, not phone service. It's sometimes called Naked DSL. Qwest and Verizon both offer Naked DSL, and other DSL providers might follow suit.

A federal law says that when you switch telephone providers, you should be allowed to keep your existing phone number. But you'll have to ask for it; it doesn't happen automatically. And there might be circumstances in which you can't keep your existing phone number. If you're switching to Vonage, go to http://www.vonage.com/identity/vonage/includes/lnploa.pdf and fill out the form online. You'll be told whether you can transfer your phone, as well as the steps you have to take to have it switched. The change might not take effect immediately, and you might get a temporary phone number that you can use with your Vonage phone while the changeover happens.

5.11.4. Make Skype Calls at Work

If you try to make Skype calls at work, you might get a "Skype error #1102" and be unable to make a connection. If that happens, it means your business's firewall won't let you through. To make the calls, you'll have to tell the system administrator to open up unrestricted outgoing TCP access to all destination ports above 1024, or to port 80. (Destination ports above 1024 is a better bet, however.) That will let you make the connection. If you want better voice quality, tell the administrator to also open up outgoing UDP traffic to all ports above 1024, and to allow UDP replies to come back in.

    Windows XP Hacks
    Windows XP Hacks, Second Edition
    ISBN: 0596009186
    EAN: 2147483647
    Year: 2003
    Pages: 191

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