olution to ROADM interoperability. With ROADM MSA, carriers can add and drop single wavelengths to ROADMs manufactured by other vendors. See Figure 4-6 for an example of an open source ROADM. AT&T announced they were able to add and drop single 100 Gigabit wavelengths between Ciena and Fujitsu ROADMs. Legacy ROADMs may not be upgradeable due to older, fixed optical parts that are not programmable for compatibility to the Open ROADM Akamai-The Largest Content Delivery Network in the United States People that watch live sporting events, play online games, or stream movies over the Internet expect to stream these events and movies without experiencing delays that interrupt content they're watching. Content delivery networks are an important factor in their ability to seamlessly watch high-quality live and streamed video and sporting events over broadband networks. As the name implies, content delivery networks deliver content over broadband networks. They route the growing amounts of live-streamed sports events, streaming television and movies, and real time gaming traffic. Content delivery network customers are the content providers that create and film content including large social networks, financial firms, and online gaming companies. Online retailers and large banks also use content delivery network services. The above content providers, online retailers, and financial firms hire www.TechnicalPDF.com content delivery networks to ensure that traffic to their customers is not delayed or interrupted because of congestion resulting in dropped packets. At Akamai, technicians monitor networks at their Network Operations Centers (NOCs) in Cambridge, MA, Santa Clara, CA, Krakow, Poland, and Bangalore, India. A NOC is a location where network engineers monitor live traffic. Monitoring software used in these NOCs depict live traffic in real time. The software provides engineers information on paths packets travel, congested routes, and alternate routes available in the event of outages and congestion. NOC staff reroute 