Examples of Converged Networks

Data and voice communications in Internet Protocol packets can be transported over the ”public” portion of the Internet used for email and Web surfing. It also can be sent over separate Internet Protocol networks built by carriers. Sending it over carriers' own networks provides more assurance of quality for voice. Carriers that build their own IP networks engineer them for certain quality of service standards.

Examples of carriers that will carry converged traffic on upgraded networks include:

• Cable TV companies

• Competitive local exchange carriers (CLECs)

• Traditional long distance suppliers and Internet backbone providers such as AT&T, Sprint Communications, Cable & Wireless and WorldCom

• Long distance providers such as Qwest Communications, Inc., Level 3 Communications, Broadwing and Global Crossing

• Cellular carriers between their switches

• Local Bell operating companies such as Verizon and SBC

• Internet Service Providers

• Utilities entering telecommunications

Many startup competitive local exchange carriers and regional carriers are looking for ways to lower the cost of building networks. Optical networking technologies and softswitches are important enabling technologies.

Free Calls or Low Priced Calls over the Internet

Starting in 1995, users made free voice calls over the Internet from their PCs. (See Figure 5.21.) They did so by installing proprietary software from companies such as VocalTec Communication, Ltd. and sound cards into their personal computers. They also plugged telephones, headsets or microphones into their PCs. The quality of these calls was inferior to that available with standard telephones connected to the public switched network. Moreover, PCs could only be used to call people with compatible software. However, many customers were happy to be able to make free long distance calls. This was particularly popular for international calls and calls between college students and their parents.

Both Net2Phone and Dialpad now offer long distance to consumers from either their own telephone or from PCs. The software to enable consumers to place calls over the Internet is available free from the Net2Phone Web site. Net2Phone has sites all over the world from which people with PCs equipped with its software, a headset or microphone and soundcards can place discount calls back to the United States. Users place local calls to Net2Phone switches, which then route the calls over portions of the Internet backbone that Net2Phone rents from other carriers.

H.323—A Way to Make Telephone Calls over IP

In July 1996, Intel Corporation announced a free software program that works on Microsoft Windows™ 95 and later operating systems. The software uses the H.323 standard as an agreed-upon way for users to make voice calls from PCs connected to the Internet. Users with H.323-based software from any vendor are able to call any telephone or PC on the public network, as seen in Figure 5.21. H.323 is the International Telecommunications Union-defined standard originally designed for sending video over packet networks. Intel and Microsoft hoped to increase demand for PCs with promotion of an open standard for voice over the Internet Protocol from computers.

Prepaid Calls over the Internet

Carriers including Net2Phone, Dialpad and Delta Three, Inc. sell telephone service that is routed from customers' telephones to the Internet. To use the service, customers dial a toll-free telephone number and their PIN number. The local telephone company then routes the call to the Internet telephony service provider (ITSP) point of presence (POP). The POP contains the Internet Telephony Service Provider's switch, which:

• Packetizes, digitizes and compresses the voice

• Routes the call to the Internet

• At the receiving end, converts the packets back to a form compatible with the circuit switched network (see Figure 5.22)

  Figure 5.22. Prepaid calls via the Internet.

  

• Tracks billing information

Many of these providers sell the long distance on a debit card basis. For example, Delta Three sells debit cards to users who can charge the card to any major credit card. The cards are available in increments of $25, $50, $100 and $250. This eliminates credit checks and billing by the Internet telephony provider.