A “Carrier of Carriers” is a wholesale bandwidth service provider that sells bulk bandwidth to other communication service providers, who in turn resell connectivity services to enterprises or retail customers. Wholesale bandwidth providers include large integrated telecom operators having surplus capacity in their networks or fiber-rich utilities such as railways, electricity companies, oil and gas utilities that have significant fiber assets and right of way along railway tracks, power lines or oil & gas pipelines. In many countries, central or state governments choose to invest in building a high-capacity optical fiber network using a universal service obligation fund (USOF) and lease bandwidth to other communication service providers.
Bandwidth Scalability: Since wholesale networks are designed to deliver bandwidth services to multiple customers, the scalability requirements are typically huge. DWDM networks with 40 or 80 channels and each channel carrying 10, 40, 100/200/400 Gbps of traffic are not uncommon. Also, at intermediate locations large scale switching/grooming of wavelengths, circuit or packet traffic is required.
Technology Diversity: Since the client networks can be running on multiple technologies and interfaces, a wide variety of technologies and interface speeds need to be supported. Some of the most common interfaces are PDH, SDH/SONET, OTN, Ethernet on the client side. The connection speeds desired can range from megabits gigabits. Also the nature of network-side services could be at L0 (wavelength layer), L1 (circuit layer), L2/L3 (packet layer) depending on end-customer requirements.
Product Flexibility: Many a times, it’s difficult to predict upfront as to what services will be adopted by the market. As a result, the optical platforms used should not be rigid and must have the necessary flexibility to continuously evolve and support an arbitrary mix of circuit and packet services ranging from 100% circuit to 100% packet or anywhere in-between. The product architecture should use reprogrammable hardware and software modules to ensure greater reusability in dynamic network scenarios.
Differentiated Services: Another key requirement for wholesale service providers is the ability to offer a range of “right-fit” service level agreements (SLAs) in terms of protection (e.g., unprotected, shared protection, dedicated protection), quality of service (mission-critical, real-time, non-real-time, best effort) and performance metrics (e.g., latency, jitter, packet loss). This requires a sophisticated traffic processing engine along with a comprehensive network management implementation.