om a customer's perspective, the principal advantages of VoIP include consolidated voice, data, and multimedia transport; elimination of parallel systems; the ability to exercise PSTN fallback in the event that the IP network becomes overly congested; and reduction of long- distance voice and facsimile costs. For an ISP or CLEC, the advantages are different but no less dra- matic, including efficient use of network investments due to traffic con- solidation, new revenue sources from existing clients because of demand for service-oriented applications that benefit from being offered over an IP infrastructure, and the option of transaction-based billing. These can collectively be reduced to the general category of customer service, which service providers such as ISPs and CLECs should be focused on. The challenge they face will be to prove that the service quality they provide over their IP networks will be identical to that provided over traditional, circuit-switched technology. Major carriers are voting on IP with their own wallets, a sure sign of confidence in the technology. As we observed earlier, the key to IP's success in the voice provision- ing arena lies with its "invisibility." If done correctly, service providers can add IP to their networks, maintaining service quality while dramat- ically improving their overall efficiency. IP voice (not to be confused with Internet voice) will be implemented by carriers and corporations as a way to reduce costs and move to a multiservice network fabric. Virtually every major equipment manufacturer-including such notables as Lucent, Nortel, and Cisco-has added SS7 and IP voice capability to their router products and access devices, recognizing that their primary customers are looking for IP solutions. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Telephony Chapter 3 IP-Enabled Call Centers Ulti