Optical networks provide the highest-speed links in existence today. With that speed comes a requirement for extremely fast failover mechanisms, to ensure that the massive amounts of traffic flowing through these pipes are disrupted for only a minimal amount of time.
Despite the massive popularity of Ethernet networks, one of Ethernet’s greatest shortcomings has been its lack of network management tools. For years, network administrators have wished for a way to monitor and manage Ethernet networks in the same way they can monitor SONET/SDH, ATM, and Multiprotocol Label Switching (MPLS) networks. This need has become more urgent as Ethernet continues to move beyond the local area network (LAN) and into metro area networks.
After years of waiting, a solution is now available to properly monitor Ethernet networks. Ethernet Operation, Administration, and Maintenance (OAM) provides a set of tools that you can use to monitor and manage the state of Ethernet links. The IEEE has defined two standards for Ethernet OAM: 802.1ah and 802.1ag. The 802.1ah standard, also known as link fault management (LFM), provides fault management for a single directly connected link. The 802.1ag standard, also known as connectivity fault management (CFM), provides OAM across multiple nodes.
Ethernet OAM provides three general features: fault monitoring, path discovery, and fault isolation. High availability ...