Abstract
Ethernet has become the predominant technology in the Local Area Networks (LANs) due to its simplicity and cost effectiveness. It has been evolved over the past years from a simple shared medium protocol to a full duplex switched networking solution, from which originates almost 90 percent of the overall IP traffic that flows throughout the internet. Its dominance has led many players in the telecommunication market (equipment manufacturers, network and service providers, end users, etc) to consider Ethernet also as a candidate networking solution to the MAN (Metropolitan Area Networks) and WAN (Wide Area Networks) environment Already several efforts are underway by international standardisation bodies and forums like the Institute of Electrical and Electronics Engineers (IEEE), Internet Engineering Task Force (IETF), International Telecommunications Union (ITU) and Metro Ethernet Forum (MEF) to extend Ethernet into the MAN environment. The focus of this article is to provide a concise overview of these initiatives and analyze the challenges that must be faced for the transformation of Ethernet into a carrier-class networking solution capable of providing telecommunication services (Ethernet Services) into the MAN.
Key Terms in this Chapter
MAN: Metropolitan area network (MAN) is a network connecting different LANs and is usually located in a large geographical area, which can be a city.
SLA: Service level agreement is the contract between the user and the service provider and describes technical parameters of the service. The most common parameter of a SLA is the latency, packet loss and network availability.
MAC Address: The media access control (MAC) address is a unique address identifier allowing the identification of a network device attached to a network. The MAC address is assign to every device by its manufacturer and is a 48 bit hexadecimal number.
LAN: The term local area network (LAN) is used mainly to describe a network of computers, servers, switches and other network devices that are located in a small geographical area like an office or a building. In some cases, the term is also used to describe the network of a campus.
UNI: User network interface is the demarcation point between the user’s network and the network provider’s network.
SDH: Synchronous digital hierarchy, the European counterpart to SONET, is a networking technology based on time division multiplexing allowing the transmission of data in speeds of STM-1 (155 Mbps), STM-4 (622 Mbps), STM-16 (2.5 Gbps), or STM-64 (10 Gbps).
VLAN: The virtual LAN is a logical segregation of a physical LAN into many different logical LANs. A computer connected to one Virtual LAN cannot communicate directly with a computer connected to a different virtual LAN, even if they are both connected to the same physical LAN.
WAN: Wide area network (WAN) is the network covering a large geographical area connecting different LANs and MANs.