A method and system for providing a customer network with high speed access to a carrier network is provided The system comprises an access device for providing a communication path for the customer network, a first concentrator device that is operable to establish a communication path with the carrier network, and a second concentrator device that is operable to establish a communication path with the carrier network The access device is operable to receive data traffic from the customer network and to forward the data traffic within the system The access device and the first concentrator device cooperate to form a first virtual channel for allowing data traffic to flow from the customer network to the carrier network and from the carrier network to the customer network and wherein the first virtual channel is the primary communication channel for the customer network The access device and the second concentrator device cooperate to form a second virtual channel for allowing data traffic to flow from the customer network to the carrier network and from the carrier network to the customer network and wherein the second virtual channel is a backup communication channel for the customer network The system is operable to switch the primary communication channel from the first virtual channel to the second virtual channel upon detection of a failure in the first virtual channel

Ip multi-homing

Keywords: Optical network ; failure ; alarms Reference LCA-ARTICLE-2001-004 Record created on 2004-08-31, modified on 2017-05-12

A review on Fault Location Methods and their application to optical networks

Networks used in mission-critical applications must be highly fault-tolerant. The authors propose an FDDI-based reconfigurable network (FBRN) that can survive multiple faults. An FBRN consists of multiple FDDI trunk rings and has the ability to reconfigure itself in the face of extensive damage. They consider three classes of FBRNs depending on their degree of reconfigurability: N-FBRN (nonreconfigurable), P-FBRN (partially reconfigurable) and F-FBRN (fully reconfigurable). They analyze the performance of FBRNs in terms of their available bandwidth in the presence of faults. In mission-critical systems, it is not enough to ensure that the network is connected in spite of faults; the traffic carrying capacity of the network must be sufficient to guarantee the required quality of service. They present a probabilistic analysis of the available bandwidth of FBRNs given the number of faults. They find that a fully reconfigurable FBRN can provide a high available bandwidth even in the presence of a large number of faults. A partially reconfigurable FBRN is found to be an excellent compromise between high reliability and ease of implementation. >

On available bandwidth in FDDI-based reconfigurable networks

The first high-speed network to meet the Safenet standard's bandwidth requirements, the Fiber Distributed Data Interface (FDDI) needs help to meet Safenet's fault tolerance requirement. Researchers have proposed a number of FDDI-based network architecture designs for improving fault tolerance. An architecture called FBRN (FDDI-Based Reconfigurable Network) provides enhanced fault tolerance by using (a) multiple FDDI networks to connect hosts, and (b) efficient fault detection and network configuration algorithms. To provide fault-tolerant real-time communication with the FBRN architecture, users must manage network resources properly. We sought to accomplish this by using a fault-tolerant, real-time management mechanism with online and offline components. We focused on achieving high performance by designing efficient and effective online and offline management algorithms to work around multiple faults.

Fault-tolerant, real-time communication in FDDI-based networks

Fault identification and location in optical networks must cope with a multitude of factors: (i) the redundancy and the lack of coordination (internetworking) of the managements at the different layers (WDM, SDH/SONET, ATM, IP); (ii) the large number of alarms a single failure can trigger; (iii) the difficulty in detecting some failures and the resulting need to cope with missing or false alarms.

/pdf/failure-location-in-wdm-networks-k1v6gro62b.pdf

Failure Location in WDM Networks

An automatic reconfiguration of counter-rotating rings that significantly increases the reliability of a network is described. The automatic failure isolation and reconfiguration methodology (FIRM) uses flags and management frames to bypass both single and multiple link failures as well as cable failures. FIRM uses WRAP-D switching along with the beaconing process to locate some failures which cannot be located by beaconing process alone. Examples illustrating the reconfiguration procedures are presented. >

R. Sankar

Papers

Automatic failure isolation and reconfiguration (ring networks)