e numbers are derived. For example, it would take 500,000,000 simultaneous calls (1 billion people talking on the phone) to generate 30 Tbps at 64,000 bps DSOs. 5. C. Metz, Cisco Materials. 6. Extending the reference/experience horizon from 12 months in the past and 18 months into the future would help technology providers bring better and more revenue-generating products to the market. 7. NP-complete refers to the complexity class of decision problems for which answers can be checked for correctness, given a certificate, by an algorithm whose run time is polynomial in the size of the input (that is, it is NP) and no other NP problem is more than a polynomial factor. Informally, a problem is NP-complete if answers can be verified quickly and a quick algorithm to solve this problem can be used to solve all other NP problems. 8. Gee-Kung Chang, "Optical Label Switching," DARPA NGI PI Meeting, McLean, VA, October 4, 2000. 9. Often technology vendors make the pitch that the cost of bandwidth goes down using this or that technology. However, there is a procedural disconnect. In making those pitches, they are talking to the end user. Yet it is the carriers that are going to purchase the equipment these vendors manufacture. Therefore, the equipment vendors have to talk to Chapter 7 the carrier; they have to stimulate the interest of and show advantages and gains to the carriers. 10. O. Gerstel and R. Ramaswami, "Optical Layer Survivability: A Services Perspective," IEEE Communications Magazine 38, no. 3 (March 2000): 104-113. 11. X. Fang, R. Iraschko, and R. Sharma, "All-Optical Four-Fiber Bidirectional Line-Switched Ring," IEEE Journal of Lightwave Technology 17, no. 8 (August 1999): 1,302-1,308. 12. Adva Optical Networking White Paper, "Applications of Switch Matrices in Metro Optical Networking," May 15, 2001. 13. Neil Jerram and Adrian Farrel, "MPLS in Optical Networks-An Analysis of the Features of MPLS and Generalized MPLS and Their Application to Optical Networks, with Reference to the Link Management Protocol an