|Issue:||Latin America III 2000|
|Topic:||ATM Forum – The Internet in Latin America “Moving the Message – Backbone Transmission and Access Strategies”|
|Organisation:||The ATM Forum|
Often touted as a competitor to IP (Internet Protocol), ATM (Asynchronous Transfer Mode) is actually at the heart of business-class IP services. Although it is ATM that makes possible many IP services, it also provides a platform for many non-IP services as well. ATM is a highly flexible and scalable networking transport technology supporting mixed voice, data, and video applications. ATM technology can be utilised in the LAN (local area network), MAN (metropolitan area network), and WAN (wide area network). ATM is used in both private and public networks.
In enterprise networks, ATM is used in LAN backbones, in LAN up-links to the WAN as well as in MANs, in WAN access and backbones as a consolidation and convergence platform. Service providers of all types (e.g. voice, Internet, and application service providers) use ATM to provide cost effective replacements for leased line networks, platforms for frame relay services, and integrated access services – from fractional high speed (T1/E1 to nxT1/E1) connections. ATM is also used as a business-class foundation for IP-based services such as e-Commerce. ATM is the fastest growing transport technology for next generation networks worldwide. Deregulation in Brazil has spurred recent growth in ATM deployments in that country. Brazilian service providers (incumbents and mirrors) are utilising ATM in satellite networks, in core backbones and to provide VPN (virtual private network) services. Other countries in Latin America are developing similar ATM applications. In fact, Latin America is the fastest growing region for ATM deployment according to Yankee Group. IDC shows significant growth in ATM ports in Latin America. ATM Value Proposition ATM networks have a low Total Cost of Ownership (TCO). This includes not only the equipment costs, but also the recurring transmission costs, fault and performance management costs, moves /adds and changes costs. TCO, in the case of a service provider, also includes the operations, administration, billing, service qualification and service activation costs. Additionally, because ATM networks have high reliability and availability (e.g. built-in automatic re-route on failure), they provide the most cost-effective platform for mixed voice, video, and data applications requiring guaranteed quality-of-service. Many case studies exist for ATM deployments that have saved users 20-50% of their total networking costs. Existing network providers benefit from ATM. In many enterprises, data networks exist separately from voice and video networks. They use separate equipment utilise and require separate staff to manage them. Many have at least six separate operational networks on average. There are significant cost savings by integrating these disparate networks onto an ATM platform. ATM is unique in the breadth of services and applications it can interwork with. Because of such capabilities, ATM is viewed as a universal “convergence” technology. For new “green-field” networks, ATM is also beneficial. Many new service providers realise that they will have to provide more than a data-only or voice-only network service in order to be competitive and profitable. ATM is unique in its ability to provide guaranteed quality of service for delay-sensitive services such as voice. ATM is being deployed in these networks as a “multi-service” platform – enabling the service provider the greatest flexibility for provisioning new hi-margin services. ATM Backbone Transmission Strategies What makes ATM powerful in backbone transmission strategies? 80% of service providers today have an ATM core in their network. These service providers have discovered that ATM is the best solution for aggregating their network traffic over the WAN. ATM provides a highly scalable (from nxDS0 to OC-48+) and highly reliable (carrier-grade) technology for backbone trunking. Current work items in The ATM Forum ensure that an ATM backbone investment is future-proof: FAST (frame-based ATM over SONET/SDH) for efficiently transporting 64KB frames in the core, UTOPIA 5 (OC-768 (40 Gbps) physical interconnect) for scalability, and MPLS Interworking for convergence with the next generation IP world. Many backbones, especially green-field backbones, are built with fiber optics cable. Three recent ATM Forum work items ensure ATM remains a great transport technology for optical networking: a cell-based 1000 Mbps interface, a frame-based 10Gpbs interface, and optical channel mapping. The cell-based 1000 Mbps physical interface allows for efficient transport of ATM cells directly on the physical media without using any frame structure. The frame-based ATM interface (level 4) is an interface for packet and cell transfer between a physical layer device and a link layer device, for aggregate bandwidths of OC-192 ATM and Packet over SONET/SDH (POS), as well as 10 Gbps Ethernet applications. ATM Access Strategies ATM is also key to access strategies where more than just low speed data is being transmitted. ATM allows for the most efficient transmission of compressed voice and video simultaneously with data. The voice and video are compressed and are still “carrier-quality”. Silent intervals in voice calls allow other information bits to be transferred over the access line via a technique called silence suppression. These techniques have enabled users of ATM access strategies to realise 8-fold to 200-fold increase in the number of “connections” they can support over the same access line. For this reason, the DSL Forum has decided to support Voice over DSL (VoDSL) or Loop Emulation Service (LES) over ATM. While VoDSL is an ATM access strategy for areas with large in-ground copper infrastructure, this same ATM-based access architecture for LES works just as well with other types of physical access and is especially suited to the growing area of broadband wireless access. Beyond Speeds & Feeds So, ATM is integral to both backbone and access strategies. However, the value proposition for ATM is based on more than its capability to provide efficient aggregation and high-speed transmission for mixed applications. ATM provides more than just speeds and feeds. Whether it is ATM in the backbone or access, there are other aspects of the technology that make for a sound business case: network and service management, physical media supported, test and security. ATM is specified for more than 30 different physical media types including several forms of copper twisted pair, coax, wireless, and both plastic and glass fiber optics. The ATM Forum has developed more than a dozen specifications for network and service management – encompassing all elements in the management domain. Work is now focusing on CORBA-based management and billing between providers. There are more than 30 test specifications for inter-operability, conformance, and performance testing. There are specifications for security of the data, control/signalling, and management information in an ATM network. In combination, these aspects make ATM unique among transport technologies for its capability to provide multi-vendor networks meeting the requirements of a secure, reliable, flexible platform for VPN, ASP or IP-based applications such as e-Commerce. Two additional factors explain why ATM is essential for all xSPs (x=any type of service or short-hand for application service provider, data service provider, Internet service provider, broadband content service provider, voice service provider, VPN service provider, etc.) The robustness of the ATM routing algorithms, including provisions for re-route on failures, is essential for xSPs. Also, the ability to dynamically establish connections for new network users and to auto-configure these connections for fast service provisioning is key. ATMs Chief Rivals ATM is often stated to be “in competition” with frame relay, IP, gigabit Ethernet, packet over SONET/SDH (POS), and IP over photons. While all of these other technologies may exist stand alone (i.e. without ATM), service providers and enterprise network managers have found that ATM works synergistically with all of these technologies – providing for a more robust network. In some cases, these “competitors” are just another physical layer which ATM can run over or another service that ATM can support. Today, ATM brings necessary traffic engineering to IP and high-speed backbone and network interconnection to frame relay and leased line services. It can readily support gigabit Ethernet links – providing a robust WAN connection. ATM connections can run over POS links – providing a robust end-to-end service. IP over photons is a new technology that is useful in a high-speed core. However, new technologies take time to become cost-effective and business-class or carrier-grade. MPLS interworking is currently being developed. MPLS interworking will be the key glue in assimilating the promised speed and simplicity of IP over photons with the strengths of an ATM architecture. Putting it in Perspective ATM is not a senior citizen nor is it a newborn in the world of networking technologies. ATM is well developed and proven and is now enjoying significant deployment worldwide. The business case for ATM is now extending well beyond the largest first tier networks and those with the most demanding applications. Small city governments and retailers are proving that ATM is the most cost-effective technology to meet their total needs. Service providers are starting to address the needs of 3rd and 4th tier markets – using ATM to provide cost effective networking services to small and medium businesses. Currently, ATM carrier switches represent the largest category of ATM equipment sales worldwide. More than 80% of the Internet today runs on ATM. ATM ISP switches represent the fastest-growing category of ATM equipment sales. While IP networks get all the hype, ATM is getting deployed-typically in order to provide a reliable platform for IP services. ATM provides a robust platform providing lower total cost of ownership for enterprise, public carrier and service provider networks. ATM is central to a good backbone transmission and access strategy – for IP, frame relay, leased line, or integrated voice, video and data services. Conclusion More than 170 ATM Forum specifications exist. So, where does one start? You do not have to order the whole menu – only the necessary pieces for your specific application (the remaining pieces are future options). The ATM Forum was founded in 1991 to promote the development of ATM technology while supporting international standards and to promote awareness of ATM and its applications. Membership in The ATM Forum provides a venue to interact with the community of experts on ATM, to enhance your knowledge of what is happening in the marketplace and the opportunity to position your company as a credible player in the broadband communications arena. You can find out more about ATM technology and its application at The ATM Forum web site – www.atmforum.com.