Universal Method for Constructing Fault-Tolerant Optical Routers Using RRW

High-speed data transmission enabled by photonic network-on-chip (PNoC) has been regarded as a significant technology to overcome the power and bandwidth constraints of electrical network-on-Chip (ENoC). This has given rise to an exciting new research area, which has piqued the public’s attention. Current on-chip architectures cannot guarantee the reliability of PNoC, due to component failures or breakdowns occurring, mainly, in active components such as optical routers (ORs). When such faults manifest, the optical router will not function properly, and the whole network will ultimately collapse. Moreover, essential phenomena such as insertion loss, crosstalk noise, and optical signal-to-noise ratio (OSNR) must be considered to provide fault-tolerant PNoC architectures with low-power consumption. The main purpose of this manuscript is to improve the reliability of PNoCs without exposing the network to further blocking or contention by taking the effect of backup paths on signals sent over the default paths into consideration. Thus, we propose a universal method that can be applied to any optical router in order to increase the reliability by using a reliable ring waveguide (RRW) to provide backup paths for each transmitted signal within the same router, without the need to change the route of the signal within the network. Moreover, we proposed a simultaneous transmission probability analysis for optical routers to show the feasibility of this proposed method. This probability analyzes all the possible signals that can be transmitted at the same time within the default and the backup paths of the router. Our research work shows that the simultaneous transmission probability is improved by 10% to 46% compared to other fault-tolerant optical routers. Furthermore, the worst-case insertion loss of our scheme can be reduced by 46.34% compared to others. The worst-case crosstalk noise is also reduced by 24.55%, at least, for the default path and 15.7%, at least, for the backup path. Finally, in the network level, the OSNR is increased by an average of 68.5% for the default path and an average of 15.9% for the backup path, for different sizes of the network.

HP-SFC: Hybrid Protection Mechanism Using Source Routing for Service Function Chaining

Service Function Chaining (SFC) is an emerging paradigm aiming to provide flexible service deployment, lifecycle management, and scaling in a micro-service architecture. SFC is defined as a logically connected list of ordered Service Functions (SFs) that require high availability to maintain user experience. The SFC protection mechanism is one way to ensure high availability, and it is achieved by proactively deploying backup SFs and installing backup paths in the network. Recent studies focused on ensuring the availability of backup SFs, but overlooked SFC unavailability due to network failures. This paper extends our previous work to propose a Hybrid Protection mechanism for SFC (HP-SFC) that divides SFC into segments and combines the merits of local and global failure recovery approaches to define an installation policy for backup paths. A novel labeling technique labels SFs instead of SFC, and they are stacked as per the order of SFs in a particular SFC before being inserted into a packet header for traffic steering through segment routing. The emulation results showed that HP-SFC recovered SFC from failure within 20–25 ms depending on the topology and reduced backup paths’ flow entries by at least 8.9% and 64.5% at most. Moreover, the results confirmed that the segmentation approach made HP-SFC less susceptible to changes in network topology than other protection schemes.

Improved Routing and Signaling Functions of PNNI Protocol for High Network Stability

The improved routing and signaling functions of PNNI protocol is presents in the paper. The improved this function of PNNI protocol are to use topological network redundancy and create backup paths. This improved PNNI provides high network stability, if the network topology changes rapidly.

Packet Transport Network Recovery System with Examination of Data Transmission Quality

A packet transport network recovery system based on failure pattern under examination of transmission quality is proposed. Network failures are segmented into one of the three patterns: single failure of a node, failures of multiple nodes, and failures of multiple network areas. The single failure is recovered by a protection scheme. For failures of multiple nodes or multiple areas, recovery is performed by a node-based multiple-backup operation plane scheme or by an area-based multiple-back operation plane scheme, respectively. A unique recovery ID is assigned to each failure pattern and backup paths with the recovery ID are stored in each node. When network failures occur, the network management server determines the type of failure and sends the appropriate recovery ID to the nodes. Then recovery paths are configured. Our proposed system took about 0.5[Formula: see text]s to configure 1000 backup paths after failures were detected, compared to about 4[Formula: see text]s by a conventional scheme. For the examination of data transmission quality, multiple paths that do not share the same link are grouped and configured concurrently. The number of groups is regarded as the performance of the configuration. The performance of the proposed system is about three times faster than a configuration without grouping.

Proteção e roteamento multicaminho em redes ópticas elásticas com multiplexação por divisão espacial

The introduction of space division multiplexing in optical networks brings new challenges for network protection since the lightpath can span high capacity and transmit data at different rates. In addition, these networks suffer from the fragmentation of the spectrum that hinders contiguity and continuity constraints and, therefore, increases the block. To address these problems, in this paper, we propose the protection algorithm for elastic optical networks with spatial division multiplexing through multipath routing and shared backup paths.