Companies such as Z-Wave, ZigBee, and INSTEON have a vision to transcend this and create a more whole-home wireless infrastructure that intercommu- nicates and functions more like a wireless LAN, focused on these home automation applications, but they’re not there yet. When these features are routinely available, we expect vendors like HAI to support these wireless interfaces. 287 Chapter 14: Wirelessly Securing, Monitoring, and Automating Your Home Who’s going to beat X10 for home automation? The X10 standard for home automation has been around for a long time, serving as a glitchy means to automate your light switches, ther- mostats, security devices, sprinklers . . . heck, even your Christmas tree. But major efforts are underway to replace the aging X10 standard — the ZigBee Alliance ( www.zigbee.org), Z- Wave (Zensys, www.zen-sys.com), INSTEON (Smarthome, www.insteon.com), and Univer- sal Powerline Bus (Powerline Control Systems, www.pcslighting.com). Each of these approaches promise two-way, low-power, nar- rowband mesh networking that will enable all consumer electronics and other devices in the home to communicate with each other and with sources outside the home via Internet gateways. The ZigBee Alliance has an IEEE open standard (IEEE 802.15.4) at the core of its technology. Although it has not shipped any product yet, it does have several big companies as members and expectations of products sometime in 2006 if not sooner. Zensys’s Z-Wave technology has had chips on the market for more than three years and now is into its second generation chip. Consumer products based on Z-Wave first hit the market in 2005. INSTEON is the most compatible with the X10 customer base: It is the only one of these prod- ucts that is backwards-compatible with X10. Consumers with X10 devices installed don’t have to rip them out — they can just add on INSTEON units to complement them. Where ZigBee and Z-Wave are both wireless only, INSTEON also uses a home’s existing wiring or powerline together with wireless. Products are already on the market at www.smarthome. com . Powerline Control Systems has also set out to top X10 and has lighting control-focused prod- ucts on the market using its Universal Powerline Bus (UPB) technology. The firm has lined up some players in the home automation space to support UPB in their products, but the other three mentioned initiatives appear to have more industry backing at this time. There’s no telling who the ultimate winner in this race will be, if there is a single winner. However, all these products will likely be on the market for a while before any clear winners and losers appear. For now, know that each of these com- panies are rapidly expanding their product lines in the home automation space, and you can expect to hear more about them in the major magazines and online stores. 21_595830_ch14.qxd 8/26/05 7:59 PM Page 287 288 Part IV: Cool Wireless Toys 21_595830_ch14.qxd 8/26/05 7:59 PM Page 288 Chapter 15 It’s Your Dime: IP Calls and Your Wireless Network In This Chapter ᮣ Understanding VoIP ᮣ Figuring out the VoIP pieces and parts ᮣ Choosing Wi-Fi VoIP hardware ᮣ Looking at VoIP services ᮣ Using softphones ᮣ VoIPing on the road W e’ve long been proponents of Voice over Internet Protocol (or VoIP, as it’s more commonly known). In fact, the first For Dummies book we ever wrote, ten (long) years ago, was Internet Telephony For Dummies, which explained how to make free PC-to-PC phone calls over the Internet. In those intervening ten years, a lot has changed. For one thing, you don’t need a computer to make a phone call over the Internet (or over networks running Internet Protocol — many “IP phone calls” run partially or totally over private IP networks owned by the VoIP service providers). All you really need is a broadband connection (cable modem or DSL), an Analog Telephone Adapter (ATA), and a phone service that uses IP (like Vonage). In fact, VoIP has become so mainstream (at last count, more than 600,000 homes were using Vonage, and there are hundreds more companies offering similar services) that it’s almost not worth writing about. But VoIP has begun to move into the wireless networking world, and it has brought with it an entirely new way of thinking about telephone calls. In this chapter, we tell you what you need to know about VoIP-ing your wire- less network. We start off by giving you an understanding of how VoIP phone calls work, and what kind of infrastructure equipment and services you need 22_595830_ch15.qxd 8/26/05 8:01 PM Page 289 to make them work. We then talk about the hardware and software you use for the calls themselves: Wi-Fi VoIP handsets (think of cordless phones on steroids) and softphones, which use software on wirelessly-equipped laptops or handheld computers. Then, we spend a little time dealing with the security and performance issues that VoIP brings to the Wi-Fi network. We conclude by talking about how Wi-Fi and VoIP can work together not only in your home or business, but also when you’re on the road, to give you cheap (or free) calls from anywhere you happen to be. There’s a lot to VoIP, and much of it is entirely independent of network type — wireless or wired, it doesn’t really matter. In this chapter, we cover some VoIP basics that apply across all network types and then spend our time looking at the intersection of VoIP and Wi-Fi. You could write a whole book on VoIP alone (check out VoIP For Dummies by Timothy V. Kelly, published by Wiley, for example). We just want to hit the highlights here as they relate to wireless. Many VoIP services and systems do not provide a full replacement for a tradi- tional phone’s Enhanced 911 (E 911) service. If you call 911, it may not be routed to the appropriate local emergency services department, and your location information may not be sent to whomever does answer the call. Some services (like Vonage) let you configure your 911 calling so that it does go to the right place and send the right information. But in these cases, if you use your VoIP system on the road, as we discuss in this chapter, you will not have the correct 911 connections. Of course, 99.99 percent of the time, this isn’t a big deal, but you should be aware of it, just in case. Unless you’re sure that things are properly configured in your VoIP system, when an emergency strikes, use a conventional landline first, a cellphone second, and a VoIP only as a last resort. Grasping the VoIP Basics The first thing to understand about VoIP (pronounced voyp, which rhymes with no word we know of in the English language) is that there isn’t a single “kind” of VoIP. Instead, as with most things Internet-related, a variety of stan- dards and protocols define VoIP, and these standards and protocols are impor- tant when you’re choosing VoIP equipment and services. Simply put, the equipment you choose must support the standards and protocols used by your VoIP service provider or network — or, if you’re doing a peer-to-peer call to another user across the Internet, you need to make sure that the standards and protocols that you both use match up. The same thing is true on the PSTN (public switched telephone network) for POTS (Plain Old Telephone Service — that’s an actual industry acronym), and for mobile networks. For POTS, these standards are about 100 years old, so no one thinks about it: Every POTS phone works without a hitch. 290 Part IV: Cool Wireless Toys 22_595830_ch15.qxd 8/26/05 8:01 PM Page 290 Mobile networks, however, are a good comparison to VoIP, as there are still dif- ferences between different providers. Just as you choose a cellular phone built for, say, Verizon’s network, you choose a VoIP phone built for a specific net- work (like Vonage’s). And like mobile networks, if two networks share the same standards (for example, Cingular and T-Mobile both use GSM networks), it’s rel- atively easy to switch from one to the other with your existing equipment. Take a long SIP The most common standard used for VoIP calls is known as Session Initiation Protocol or SIP (pronounced like what you do with a drink of water). SIP is a standardized protocol that can be used to initiate all sorts of communications sessions on the Internet and IP networks, ranging from voice calls (VoIP phone calls, in other words) to videoconferencing or even multimedia collaboration (for things like online meetings, presentations, and Webcasts). SIP’s big function in the network is to provide the mechanism for establishing calls, terminating them when they’re through, and maintaining the connec- tion in the interim. Basically, SIP makes the phone on the other end ring when you dial out on your VoIP phone, and makes yours ring when someone dials in to you. SIP doesn’t define all of the characteristics of VoIP phone calls — there are other important protocols such as the codecs (encoder/decoder algorithms used to compress analog voice into signals that can be sent digitally). And not every VoIP phone call uses SIP for call setup and initiation. Indeed, some services (like the very popular Skype service that we discuss later in this chapter) use their own proprietary protocols for call control (though Skype’s protocol is at least based on SIP). The great thing about SIP is that it is a widely accepted protocol (Skype notwithstanding), and that makes it easier to mix and match equipment and services. Although a bit of tweaking and configuration may be necessary, if a VoIP phone supports SIP, it theoretically works with any VoIP service that supports SIP. It’s sort of like Wi-Fi, where different vendors get along. Unfortunately, VoIP doesn’t have an organization like the Wi-Fi Alliance (we discuss them in Chapter 2) who spend time and money making sure this is true. Do a bit of double-checking before you make any purchases. The precise name of the SIP protocol we’re discussing here is SIP v2 (version 2), compliant with the RFC 3261 protocol (just in case you ever have to take a test on the subject!). 291 Chapter 15: It’s Your Dime: IP Calls and Your Wireless Network 22_595830_ch15.qxd 8/26/05 8:01 PM Page 291 Compressing your voice Another important protocol in any VoIP system is the compression codec used to turn your digitized voice into a signal that can easily be carried over the Wi-Fi network and through a broadband Internet connection. When you speak into the headset or handset while making an IP phone call, two things happen: ߜ Your voice is converted from analog to digital signals that can be carried as bits of data. This process (called digital-to-analog conversion) creates a relatively large (or high bit rate) digital file of your voice. Bit rate simply refers to the degree of compression of a codec. Lower bit rate codecs require less bits per second of network bandwidth and are therefore more highly compressed. ߜ This digitized voice file is compressed to a lower bit rate format using the compression codec. This makes the voice data more suitable for trans- mission across networks of unknown bandwidth or quality of service. Depending upon what kind of VoIP call you’re making (for example, from a PC, from a Wi-Fi handset, and so on), these two steps may be performed by the same device and be relatively indistinguishable. We mention them as sep- arate tasks just so you’ll understand what’s happening. Here are two important things to keep in mind about the codec you are using in a VoIP phone call: ߜ You need to use a codec that is “understood” on both ends of the call. Particularly if you’re making some sort of peer-to-peer call (making a call between two SIP phones, for example), you need to have equipment ter- minating your call on the far end that supports the same codec you’re using to make a call. This isn’t usually a problem, but can come into play if you’re getting fancy and trying to call directly to another VoIP user without going through a service. For the vast majority of calls, you never need to worry about “matching up” codecs. ߜ The lower the bit rate of the codec, the lower the perceived sound qual- ity. To put this another way, higher bit rate codecs usually sound like someone’s natural speaking voice — low bit rate codecs tend to sound sort of artificial. Relatively high bit rate calls (using codecs that require about 64 Kbps or higher in most cases) are often referred to as “toll quality” (equivalent to a standard telephone call), whereas relatively lower bit rate calls sound more like a cellphone call. 292 Part IV: Cool Wireless Toys 22_595830_ch15.qxd 8/26/05 8:01 PM Page 292 There isn’t an absolute and linear relationship between bit rate and voice quality on a call. All of the codecs used for VoIP phone calls are lossy — which means that some of the digital information captured when your voice is converted to digital signals is thrown away in the process of compressing those digital signals. The science behind compression systems improves every day, and some relatively low bit rate codecs sound subjectively better than other older and higher bit rate codecs. The impact of your VoIP codec is on your local (wireless) and access (DSL or cable modem, for example) network bandwidth requirements. Many VoIP software programs (if you’re using a PC to make calls) and hardware systems (if you’re using a dedicated VoIP device) use codecs of 64 Kbps or higher per call — actually, it will always be higher due to some protocol overhead, so expect a 64 Kbps codec to actually need about 90 Kbps of bandwidth in each direction. Although this shouldn’t overtax your Wi-Fi network (even with a very conservative throughput assumption, 802.11b can handle many such calls, and 802.11g and a even more), the real bottleneck comes into play with your broadband access connection. Most residential and small business users have relatively slow upstream connections — 128, 256, or maybe 384 Kbps. (Folks outside of North America do much better — like the folks in Hong Kong who can buy a gigabit per second connection into their homes over fiber optic cabling!) In a perfect world, with no overhead (extra bits required for underlying network protocols), you might be able to support only two calls (or a single three-way call) before you ran out of all of your bandwidth for other applications. Luckily, most VoIP systems provide a range of codecs, starting at very low bit rates (as low as 24 Kbps), to support a wider range of users. In many cases, you don’t have to do anything — the system autoconfigures itself with the best codec based upon network conditions. For example, Skype (which we discuss in the section titled “Skype-ing Your Way Around the World”) auto- configures a codec between 24 and 128 Kbps based upon your connection speed, the connection speed of the party you’re speaking with, and the con- nection between you and across the Internet. Some VoIP systems allow you to manually select a codec. The higher bit rate codecs (those above 64 Kbps) can actually sound better than a conventional POTS phone call. In fact, some of the VoIP providers we know use this as mar- keting differentiator — trying to move VoIP from “cheaper” to “better than traditional” phone services. Peer-to-peering versus calling regular phones Besides the underlying call control protocols and codecs — which are the tech- nological underpinnings of VoIP calling — the big distinction among different 293 Chapter 15: It’s Your Dime: IP Calls and Your Wireless Network 22_595830_ch15.qxd 8/26/05 8:01 PM Page 293 types of VoIP phone calls is how the calls themselves are routed across the Internet or other IP networks. There are two main methods of routing VoIP calls: ߜ Peer-to-peer: Some VoIP calls are routed directly between the two users (although the initial connection may involve a separate directory server that tells users how to find each other on the Internet). The most com- monly used peer-to-peer VoIP solution is Skype, which we mention ear- lier and which we discuss in more detail shortly. Skype has millions of users making phone calls from PC to PC across the Internet. Most peer-to-peer VoIP systems use software on PCs (or on handheld computers) to place calls. You can, however, use a special VoIP phone (a SIP phone) to place calls peer-to-peer as well by using the IP addresses or SIP address of each phone to place the call. The great thing about peer-to-peer calls is that they are usually free. You can use a peer-to-peer system to call anyone in the world for nothing, as long as you both have compatible VoIP systems and adequate (high speed) Internet connections. We’re using the term peer-to-peer somewhat loosely here. A server of some sort is often involved in the process (usually as a means of finding the people you’re calling on the Internet), but the calls themselves usu- ally travel directly from party to party across the Internet, and do not route through a centralized server. ߜ Through a service provider: Other VoIP calls travel across your Internet connection and into the network of VoIP service provider. Having this ser- vice provider in the middle of your call opens up the possibilities greatly because it expands the number of people you can place calls to (or receive calls from). In fact, with most service providers, you can make or receive calls from just about anyone in the world with a phone — just as you can with your non-VoIP phones. You get more flexibility going through a service provider, but you do have to pay for it. Whereas most peer-to-peer VoIP phone systems are free, you have to pay a monthly service charge (and often per-minute rates for at least international calls) with a VoIP service. The good news is that most VoIP services are considerably cheaper than traditional phone services. Hardware? Software? Both? As we’ve already alluded to throughout the chapter, VoIP phone calls can be made using either general-purpose hardware (a PC or handheld, in other 294 Part IV: Cool Wireless Toys 22_595830_ch15.qxd 8/26/05 8:01 PM Page 294 words) or using specialized hardware (like purpose-built VoIP phones). Generally speaking, you’re likely to see three options: ߜ Softphones: Software that runs on a PC or other computer (Mac, hand- held, Palm, and so on) and that uses the audio and networking sub- systems of that computer. Skype is an example of a softphone, as is Windows Messenger (included with XP) or iChat AV on the Mac. Some VoIP service providers (like Vonage) are now offering softphones as an adjunct to their phone-to-phone service. Although many softphones are used primarily for PC-to-PC calling, you can use some softphones with a service provider to make PC-to-telephone calls or to receive telephone-to-PC calls. ߜ ATAs: ATAs, or Analog Telephone Adapters, are hardware devices designed to connect to your local area network and broadband Internet connection. They provide a connection between traditional POTS phones and a VoIP service provider. Essentially, an ATA is a network device that converts POTS into VoIP (and back). We won’t focus on ATAs too extensively in this chapter because they are not wireless devices. However, keep in mind that ATAs are very common (and increasingly inexpensive) devices that are used by many VoIP ser- vice providers. We focus on Wi-Fi VoIP in this chapter, but you can always hook up a conventional cordless phone system to a VoIP ATA for a quick wireless connection to VoIP in your home or office. You can find ATAs that are built into a wireless router from companies like Linksys. The phone connection remains wired (there are a couple of phone jacks on the back of the router), and the Wi-Fi part of the system is meant for data only. These devices don’t have wireless VoIP, but they can be a good way to reduce clutter in your office or wherever you are placing the AP. Check out Linksys’s WRT54GP2 (designed for the Vonage network) for an example of these devices ( www.linksys.com/products/ product.asp?prid=657&scid=35 ). ߜ Dedicated VoIP phones: Many manufacturers build VoIP handsets that can communicate using SIP and have all of the pieces and parts (like DSP — digital signal processing — hardware to handle analog-to-digital and digital-to-analog conversions and codec work) to initiate and termi- nate VoIP phone calls on their own. These phones (usually called SIP phones) don’t need an ATA or a conventional phone — you just give them a network connection and the configuration data appropriate for your VoIP service, and you’re set. In the forthcoming section titled, “Taking your VoIP service wireless,” we dis- cuss a few of the more interesting dedicated VoIP phones. Staying true to our WNH&M For Dummies theme, we focus on Wi-Fi VoIP phones that leverage your wireless network for VoIP calling. 295 Chapter 15: It’s Your Dime: IP Calls and Your Wireless Network 22_595830_ch15.qxd 8/26/05 8:01 PM Page 295 Skype-ing Your Way Around the World The easiest way to bring VoIP to your wireless network is to try out Skype ( www.skype.com). It’s really painless: It’s absolutely free and it works really well, a combination that we’re particularly fond of. Skype is available for the following platforms: ߜ Windows XP or Windows 2000 PCs ߜ Mac OS X 10.3 (Panther) or later ߜ Linux (Skype provides builds for several distributions of Linux; check www.skype.com/products/skype/linux/ for the latest details.) ߜ PocketPC handheld computers using Windows Mobile 2003 for Pocket PC or newer Figure 15-1 shows the main Skype window in Windows XP (the other operat- ing systems look relatively similar). As we mention earlier in the chapter, Skype is a softphone client that uses a proprietary SIP-based system for establishing and receiving calls. Skype also includes a range of codecs that are automatically configured during the call, ranging from 24 to 128 Kbps (the codec used is based upon the quality of your end-to-end connection). Skype provides several options for calling over your wireless network (or over any broadband-connected LAN): Figure 15-1: Getting into Skype. 296 Part IV: Cool Wireless Toys 22_595830_ch15.qxd 8/26/05 8:01 PM Page 296 [...]... mind with wireless VoIP if you’re a Windows XP user is a behavior of XP’s Wireless Zero Configuration system Zero Config is a great tool for finding wireless networks and getting online — it’s so easy and so integrated into the OS that we use it all the time, instead of using the software included with our wireless client adapter hardware Chapter 15: It’s Your Dime: IP Calls and Your Wireless Network. .. 802.11g access point — you can get models with 250GB for $400 and 160GB for $330 D-Link offers several wireless NAS units, such as the 40GB MediaLounge Wireless G Central Home Drive DSM-624H (www.dlink.com, $4 29) , but at almost $10 per gigabyte, it’s a pricey option to choose We mention the wireless options first because, well, this is a wireless book With wireless, you have total freedom to decide where... specific wireless requirement — like you want to put it in your car — check out your wired options as well 313 314 Part IV: Cool Wireless Toys Figure 16-2: Tritton’s wireless NAS units are easy on the pocketbook and network A lot of wireless adjunct gear — including NAS but not just limited to those devices — does not support the latest wireless security protocols embodied in WPA (See Chapter 9 for more... EASYSHARE-ONE Wi-Fi camera (www.kodak.com, $ 599 retail plus $99 for a Wi-Fi card) The EASYSHARE-ONE, shown in Figure 16-1, is a 4megapixel CCD camera with a 3-inch LCD screen, 256MB of onboard memory, and optional 802.11b Wi-Fi compatibility made available by an SDIO 802.11b Wi-Fi card Figure 16-1: Kodak’s EASYSHARE-ONE is easy to share wirelessly With the wireless capability, you can e-mail photos from... that get lost due to network errors, voice has no tolerance for delays and Chapter 15: It’s Your Dime: IP Calls and Your Wireless Network retransmits If the bits that represent a word don’t come through the network in time, you can’t get them back, at least not until the other party says, “Could you say that again?” So Wi-Fi VoIP (and all VoIP, for that matter) is dependent on a network with low latency... softphone client as an optional component For example, Vonage offers a softphone service as an add-on to its basic hardwarebased services For an additional $9. 99 a month, you get the softphone client software, an additional number for your laptop, and 500 local and long distance minutes Vonage has even inked a deal with Boingo (we discuss Boingo in Chapter 9) to integrate the softphone and Boingo’s... connection wirelessly You can also get stand-alone wireless print servers focused on that one task — D-Link’s DP-G321 Wireless Multi-Port Print Server ($ 89) features two USB 2.0 ports and one parallel port, which allows everyone on the network to access and share up to three printers off the one device You could set up a printer farm with that! The nice thing about going wireless is that any 802.11 wireless. .. roaming networks and other Wi-Fi tips for the road But if you had a Wi-Fi finder in your pocket, you wouldn’t need to boot up to figure out where your nearest hot spot is A Wi-Fi finder is a divining rod for wireless access It looks like that plastic remote control for the car locks that you get with new cars these days Operating a finder is usually a matter of pressing a button It sniffs the air for wireless. .. phones offer a simple keypad-based method for inputting ESSID and WEP keys for networks that need them, and both automatically search for open networks that broadcast their SSIDs We weren’t able to play with the beta units of the UTStarcom phone in a hot spot environment, but the ZyXEL phone is particularly easy to use — you can just scroll through a list of available networks and click a button on the phone... 306 Part IV: Cool Wireless Toys You’ll find two forms of SIP acceleration products for your home or small office network: ߜ Stand-alone devices: Stand-alone devices like the D-Link DI-102 Broadband Internet/VoIP Accelerator (www.dlink.com/products/ ?pid=426), which retails for about $60, are installed inline between your broadband Internet connection and your primary router (wired or wireless) All traffic . our WNH&M For Dummies theme, we focus on Wi-Fi VoIP phones that leverage your wireless network for VoIP calling. 295 Chapter 15: It’s Your Dime: IP Calls and Your Wireless Network 22_ 595 830_ch15.qxd. stores. 21_ 595 830_ch14.qxd 8/26/05 7: 59 PM Page 287 288 Part IV: Cool Wireless Toys 21_ 595 830_ch14.qxd 8/26/05 7: 59 PM Page 288 Chapter 15 It’s Your Dime: IP Calls and Your Wireless Network In. options for calling over your wireless network (or over any broadband-connected LAN): Figure 15-1: Getting into Skype. 296 Part IV: Cool Wireless Toys 22_ 595 830_ch15.qxd 8/26/05 8:01 PM Page 296 ߜ