c node identified through the E.164 number. In a nutshell, ENUM involves the following steps: 1. ENUM turns a phone number into a fully qualified domain name (FQDN). It does this by first adding the city, or area, and country code. For example, 555-1234 dialed in Washington, DC, becomes +1-202-555-1234, where 202 Chapter 9 IP Services is the area code, the 1 represents the North American country code, and the + indicates that the number is a fully qualified E.164 number. Then ENUM removes all the characters except for the digits and reverses the order (e.g., +1-202-555-1234 becomes 43215552021). Finally, it places dots between the digits and appends the domain E164.ARPA to the end of the string (e.g., 4.3.2.1.5.5.5.2.0.2.1.E164.ARPA), 2. ENUM issues a DNS query on the FQDN created in step 1. 3. DNS returns a list of URIs that contain information about what resources, services, and applications are associated with that specific phone number. An important feature of the ENUM protocol is that more than one type of contact information can be stored in the DNS record that belongs to a specific ENUM number. An ENUM record associated with The LIDO Organization might contain instructions for a VoIP call (e.g., h323:info@server.lidoorg.com or sip:info@sip.lidoorg.com), a fax call (e.g., fax:office@fax.lidoorg.com), and e-mail communications (e.g., mailto:info@lidoorg.com). Additional services can be devel- oped in the future and included in the ENUM name records. The phone number in ENUM can therefore be the single contact number for multiple types of com- munication, such as voice, fax, e-mail, mobile, text messaging, location-based ser- vices, and Web pages. ENUM does not replace the numeric IPv4 or IPv6 addresses that will be used to interact within IP directly. ENUM performs no conversion of signaling messages and media streams. Instead, ENUM is a framework for mapping and processing addresses of different network types. ENUM provides another way to determine the desired destination to be used to initiate communicatio