This chapter is targeted at readers who are new to Skype, or who have only heard about Skype and would like to try it. Experienced Skype users might want to skip this chapter and move on to more advanced stuff in Chapter 2 and beyond.
By reading this chapter, you will achieve three important goals: you will know what Skype is and what it can do; you will acquire a "Skype vocabulary" that will help you make better use of the hacks that follow in subsequent chapters; and you will be able to make a smooth transition to becoming a dyed-in-the-wool "Skyper." Moreover, you will achieve these goals in an action-oriented way—by doing hacks!
Additionally, by reading this chapter—an alternative title for which could be "A Whirlwind Tour of Skype's Features"—you will also see links among later hacks that would otherwise remain hidden. In short, if you are new to Skype, this chapter is for you.
Skype is both software and a bundle of services. It is an implementation of Voice over IP (VoIP) that enables people to have two-way telephone conversations over the Internet using a softphone (a piece of software that emulates the functions of regular phone hardware to make and receive calls). Many VoIP offerings are available. What makes Skype so different, and revolutionary, is that it is based on Peer-to-Peer (P2P) technology similar to Kazaa (this is not surprising, really, given that Skype was developed by the same people who brought us Kazaa). Using P2P technology means that Skype runs on a mesh of interconnected PCs spread across the global Internet (see Figure 1-1). This provides two important benefits to Skype users. First, Skype scales very well and there is little risk that it will run out of resources.
In Figure 1-1, a Skype node is simply a computer running the Skype application (also sometimes called a Skype client). Likewise, a super node is also simply a computer running the Skype application, but Skype has nominated it to take on some of the administrative and coordinating activities of its P2P network. As Skype has not made public the rules under which a node can become a super node, becoming a super node is not something over which you have any real control; though, clearly, your chances of becoming a super node are greater the more P2P friendly your Internet connection is. Of course, in reality, there are millions of nodes and thousands, or perhaps tens or hundreds of thousands, of super nodes.
A node must register and authenticate itself with a Skype server during login. Once a call is established between two nodes, where possible, a direct Internet link between the two is used. By directly connecting two nodes for calls, Skype minimizes network routing overhead and therefore can deliver better voice quality.
Skype-to-Skype calls are free. Similarly, Skype users can conference call, chat, and transfer files with each other at no cost. A conference call enables several people to participate in the same call, just as though they were sitting around the same conference table. Chat is a generic term for what people generally refer to as instant messaging services, which allow instant text communication between two or more people over the Internet.
All Skype traffic is encrypted end to end (which makes your communication more secure by obscuring information from eavesdroppers along the communication path), so it's somewhat more secure than most alternatives, including regular phone lines. End-to-end encryption means that you and the recipient of your communication have free and open access to the exchanged information, but at any point along the communication path in between, that same information is unintelligible. Skype-to-Skype calls are encrypted end to end. Incoming calls for SkypeIn and outgoing calls for SkypeOut are only encrypted while on the Skype network and are not encrypted for the part of their transmission that goes over the public telephone network.
If this were all that Skype offers, Skype would be an island unto itself and of rather limited interest. However, Skype also offers six prepaid add-on services—all at extremely low cost—that allow Skype users to make and receive calls to regular phones (as well as make free calls to other Skype users), and much more. In brief, here are the six services:
Allows you to call regular telephones, anywhere in the world, at very low rates—as low as ₠ >0.017 (about $0.021) per minute. However, rates do vary, and calls to mobile phones and some destinations can cost substantially more than ₠0.017 per minute.
Gives you a dial-in telephone number that regular phones can call. The number will be routed automatically to wherever you happen to be logged onto Skype. Phone numbers are available for several countries and their regions. Currently, a SkypeIn number costs ₠30 (about $37) per year. As an added bonus, SkypeIn comes bundled with voicemail.
Allows you to receive voicemail messages from anyone and listen to them at any time and from anywhere you are logged onto Skype. Using this service, you can also send voicemail to other Skype users, even if they are not subscribers to Skype voicemail.
This software add-on for Skype gives mobile Skype users access to thousands (more than 18,000 at the time of this writing) of wireless hotspots dotted around the globe from which to use Skype and its services. It is important to note that this is a Skype-only service and it does not support other Internet activities—for example, web browsing.
Allows you to buy custom ringtones and pictures for your profile from Skype's online store to give a personal sound and look to your Skype experience.
This Skype service simplifies the management of, and payment for, other Skype services for groups of people. Using Skype Groups, an administrator for a group can allocate SkypeOut credits, SkypeIn numbers, and voicemail to all members of a group. And all this can be done without the need for multiple credit cards and separate payments! Plus, reports can be generated to keep the managers and accountants happy.
You should also be aware that Skype is unlike any telephone system you have known before. It is based on technologies totally unlike your existing Plain Old Telephone System (POTS) that uses the Public Switched Telephone Network (PSTN), which is run by large telephone companies that we've all come to know, and in many cases hate! Nor does it use industry-standard protocols, such as the Session Initiation Protocol (SIP), which means that it does not interoperate with other VoIP services. Also, Skype has only rudimentary Private Branch Exchange (PBX) features (which allow phones within an organization to connect to each other as well as to the outside world), though this may well change as Skype matures.
Skype delivers surprisingly good voice quality calls over the Internet using surprisingly low data-rate requirements. The data rate that an Internet connection can support usually is referred to as its bandwidth. Dial-up modems have typical connection bandwidths in the range of 28.8 to 56 kilobits per second (Kbps), or 3.6 to 7.0 kilobytes (KB) per second, where 1 byte equals 8 bits. Broadband connection speed is typically measured in hundreds of kilobits per second, and possibly in megabits per second (Mbps) for fast connections, where 1 Mbps equals 1,000 Kpbs. Skype typically consumes between 3 and 16 kilobytes per second (24 Kbps to 128 Kbps). However, obviously your Skype experience will improve with higher available bandwidths. This is especially true if you are doing other things—such as browsing the Web or downloading files—while making a Skype call.
Skype works with almost any type of Internet connection: dial-up (where you connect with a modem over a regular telephone line); broadband Digital Subscriber Line (DSL, or its cousin, Asymmetric DSL or ADSL); cable broadband; local area network (LAN); Personal Area Network (PAN, usually using Bluetooth, which is a short-range wireless technology); Wireless Fidelity (WiFi) or hotspot (a public wireless connection); and even satellite Internet services (which usually connect through a radio dish pointing skyward at a geosynchronous satellite in space). Given any one of these types of Internet connections with enough bandwidth, and chances are you'll be Skyping in no time! However, you should understand that good call quality depends a great deal on having sufficient bandwidth and low latency, which is a challenge if your connection is through dial-up (poor bandwidth) or satellite (poor latency).
As you will no doubt discover, you can do things with Skype that you simply cannot do using your existing telephone system or other VoIP offerings. These "things" are not just technological, either, as many of them represent ways to save money that were just impossible before. Skype is revolutionary because of the technology it uses. For that reason, you are limited only by your imagination. Happy hacking!
Mac OS X and the Pocket PC platforms don't support the mouse right-click action. In the hacks that follow, for those cases where an item of functionality is supported by Mac OS X or Pocket PC but is not available through right-clicking, the equivalent actions to access such functionality are stated explicitly.