A translucent wavelength switched optical network (WSON) is a cost-efficient infrastructure between opaque networks and transparent optical networks, which aims at seeking a graceful balance between network cost and service provisioning performance. In this paper, we experimentally present a resilient translucent WSON with the control of an enhanced path computation element (PCE) and extended generalized multi-protocol label switching (GMPLS) controllers. An adaptive routing and wavelength assignment scheme with the consideration of accumulated physical impairments, wavelength availabilities and regenerator allocation is experimentally demonstrated and evaluated for dynamic provisioning of lightpaths. By using two different network scenarios, we experimentally verify the feasibility of the proposed solutions in support of translucent WSON, and quantitatively evaluate the path computation latency, network blocking probability and service disruption time during end-to-end lightpath restoration. We also deeply analyze the experimental results and discuss the synchronization between the PCE and the network status. To the best of our knowledge, the most significant progress and contribution of this paper is that, for the first time, all the proposed methodologies in support of PCE/GMPLS controlled translucent WSON, including protocol extensions and related algorithms, are implemented in a network testbed and experimentally evaluated in detail, which allows verifying their feasibility and effectiveness when being potentially deployed into real translucent WSON.

The first global interoperability experiment of GMPLS controlled Ethernet with VLAN tag swapping between two different implementations is successfully demonstrated. High definition video streaming is realized through a newly established Layer 2 Label Switched Path (L2-LSP). The results of this experiment can be applied to designing reliable Layer 2 networks.

We propose a novel adaptive segment repair mechanism to improve traditional MPLS (Multi-Protocol Label Switching) failure recovery. The proposed mechanism protects one or more contiguous high failure probability links by dynamic setup of segment protection. Simulations demonstrate that the proposed mechanism reduces failure recovery time while also increasing network resource utilization.

In this research, we focused on fair bandwidth allocation on the Internet. The Internet provides communication services based on exchanged packets. The bandwidth available for each customer is often fluctuated. Fair bandwidth allocation is an important issue for ISPs to gain customer satisfaction. Static bandwidth allocation allows an exclusive bandwidth for specific traffic. Although it gives communications a QoS guarantee, it requires muany bandwidth resources as known as over-provisioning. In contrast with static control, dynamic control allocates bandwidth resources dynamically. It therefore utilizes bandwidth use more effectively. However, it needs control overhead in monitoring traffic and estimating the optimum allocation. The Transmission Control Protocol, or TCP is the dominant protocol on the Internet. It is also equipped with a traffic-rate-control mechanism. An adaptive bandwidth-allocation mechanism must control traffic that is under TCP control. Rapid feedback makes it possible to gain an advantage over TCP control. In this paper, we propose an Adaptive Bandwidth Allocation (ABA) mechanism as a feedback system for MPLS. Our proposal allows traffic to be regulated adaptively as its own weight value which can be assigned by administrators. The feedback bandwidth allocation in the previous work needs round-trip control delay in collecting network status along the communication path. We call this "round-trip feedback control." Our proposal, called "one-way feedback control," collects network status in half the time of roundtrip delay. We compare the performance of our one-way feedback-based mechanism and traditional round-trip feedback control under a simulation environment. We demonstrate the advantages of our rapid feedback control has using experimental results.

In this paper, we proposed a photonic packet switching control method by used optical correlator for optical packet label packet-switched networks for next Generation networks. The main advance is rely on using the Optical Code Division Multiplexing (OCDM) code to labeling optical packets based on source routing. Based on OCDM labeling either header modification or any label swapping techniques can be avoids. With advantage of existing OCDM coding called OCDM-labels schemes to encapsulate the packets, together with optical correlator to decode the label in optical domain, which can achieve optical packet switching without header modification/label swapping techniques. The O/E/O conversion procedure at each switching device can also be eliminated. This method not only simplifies the design of switch devices in the optical domain to simplify the packet forwarding process, but also speeds up packet forwarding and increases throughput significantly.

We have successfully applied Generalized Multiprotocol Label Switching (GMPLS) architecture to the Wavelength Assignment Photonic Switching System (WAPS) to create an internet access system that can provide, between terminals, not only conventional best-effort type of IP packet forwarding, but also high-speed and Quality of Service (QoS)-guaranteed IP forwarding. In this paper the system architecture, system specifications, and system hardware/software implementations are described.

Asynchronous optical packet switching (OPS) is a promising solution to support the continuous growth of transmission capacity demand. It has been, however, quite difficult to implement key functions needed at the node of such networks with all-optical approaches. We have proposed a new optoelectronic system composed of a packet-by-packet optical clock-pulse generator (OCG), an all-optical serial-to-parallel converter (SPC), a photonic parallel-to-serial converter (PSC), and CMOS circuitry. The system makes it possible to carry out various required functions such as buffering (random access memory), optical packet compression/decompression, and optical label swapping for high-speed asynchronous optical packets.

Integration of the MPLS network and the optical mesh network is a promising approach to realize an efficient backbone network. Because large volumes of traffic incur damage from failure, survivability is important in the backbone network. In the MPLS over optical networks, a pair of primary LSP (Label Switched Path) and secondary LSP needs to be established on two optical link-disjoint routes assuming all single optical link failures. However, two link-disjoint routes in the MPLS layer may not correspond to two link-disjoint routes in the optical layer. Thus, a pair of primary and secondary LSPs should be routed considering link-disjointness in the optical layer. In the MPLS over optical networks, secondary LSPs can mutually share lightpath bandwidth if those secondary LSPs correspond to the primary LSPs that never fail simultaneously. Thus, routing of secondary LSPs should promote sharing of the lightpath bandwidth among the secondary LSPs. The primary and secondary LSPs with variable bandwidths should efficiently be packed into fewer lightpaths with a fixed bandwidth. Moreover, if all the LSPs accommodated in a lightpath can be re-routed to other lightpaths, this lightpath can then be released. By re-routing only secondary LSPs, unnecessary lightpaths may be released without disturbance of the conveyed traffic. This paper proposes an efficient routing scheme to establish primary and secondary LSPs with variable bandwidths through the MPLS over optical network. This routing scheme satisfies the above conditions. The bandwidth of each lightpath is efficiently utilized by this routing scheme, and the loss rate of LSP requests can be reduced. This paper also proposes an efficient re-routing scheme to remove secondary LSPs from selected lightpaths through which the efficiency of channel utilization in the optical links is increased, and the loss rate of LSP requests can be reduced as a result. Both the proposed routing and re-routing schemes are quantitatively evaluated and the effectiveness of those schemes is verified by computer simulation.

In order to transport an ever-increasing amount of IP traffic effectively, Photonic IP networks that employ wavelength routing and Layer 3 cut-through are very important. This paper proposes a new network design algorithm that minimizes the network cost considering IP traffic growth for multi-layered photonic IP networks that comprise electrical label switched paths (LSPs) and optical LSPs. We evaluate the network cost obtained from the developed network design algorithm that considers IP traffic growth and compare it to the results obtained from a static zero-based algorithm. The static zero-based algorithm does not take into account the history of progressive past IP traffic changes/growth until that time. The results show that our proposed algorithm is very effective; the cost increase from the cost obtained using the zero-based algorithm is marginal. The algorithm developed herein enables effective multi-layered photonic IP network design that can be applied to practical networks where IP traffic changes/increases progressively and that can be used for long term network provisioning.

Implementation issues on generalized multi-protocol label switching (GMPLS) -based photonic switching networks are experimentally analyzed. A resilient control plane architecture using in-fiber and out-of-fiber control channels is proposed to resolve issues of establishing the control plane in out-of-band networks. The resilient control plane is demonstrated in a photonic cross-connect (PXC) -based GMPLS network involving a 1,000 km transmission line. Fast signaling for provisioning and restoration operation is accomplished by implementing in-fiber control channels as primary, and the out-of-fiber control channels effectively operate as secondary and restore messaging of the control information between neighbors. The control channel protection is initiated by the link management protocol (LMP). Using the test bed, optical layer routing operation is investigated to assess the effects on the signal quality of wavelength paths, and transparent routing of the wavelength paths over one-hop and two-hops route is demonstrated within 1 dB difference regarding the Q factor. Stable operation of loss of light (LOL) -triggered restoration is demonstrated by setting the optical level threshold 5 dB higher than the amplified spontaneous emission (ASE) noise level.

In recent years, requests for new advanced features, decentralization, and improvements in the forwarding speed, have been made for IX. A new IX architecture using MPLS (Multiple Label Switching) technology (MPLS-IX) is proposed to solve these requirements and rectify the problems. In this paper, a comparison between current IX and MPLS-IX based on router's packet forwarding performance is examined, and the feasibility of MPLS-IX is discussed. Moreover, the QoS requirements to provide IX service are discussed.

In an Multi-Protocol Label Switching (MPLS) network domain, Asynchronous Transfer Mode--Label Switch Routers (ATM-LSRs) are considered the best candidate for providing the highest forwarding capability. ATM-LSRs implement a VC-merging scheme that allows many IP routes to be mapped into the same VPI/VCI label, hence supporting scalability. The VC-merging requires reassembly buffers to reconstruct an original packet from its segmented but interleaved AAL-5 cells. In this paper, we analyze the performance of an ATM-LSR with partial VC-merging capability and investigate the impact of VC-merging on the requirement of the reassembly and output buffer. The numerical computation complexity of the mathematical analysis can be reduced from O(M4) to O(M2), where M is the total number of ON-OFF sources. We also propose a closed-form equation, which approximates the distribution of the output buffer with satisfactory accuracy. Numerical results show that when incoming cells are severely interleaved, the VC-merging needs the reassembly buffer size to be of the same order as the output buffer size, which cannot be ignored.

LSR (Label Switching Router)s in MPLS (Multiprotocol Label Switching) networks map arriving IP flows into some labels on Layer 2 switching fabric and establish LSP (Label Switching Path)s. By using LSPs, LSRs not only transmit IP datagrams fast by cut-through mechanism, but also solve traffic engineering issue to optimize the delay of some IP datagram flows. So far, we have analyzed the performance of LSR focusing only on the maximum number of LSPs which can be set on Layer 2. In this paper, we will also consider the bandwidth allocated to each LSP and analyze the IP datagram transmission delay and the cut-through rate of LSR. We suppose the label mapping method as the data-driven scheme in the analytical model, so that the physical bandwidth of LSR is shared by both the default LSP for hop-by-hop transmission and the cut-through LSPs. Thus, we will investigate the impact of the bandwidth allocation among these LSPs on the performance.

In order that they fully support human activities, new network services and applications are overwhelming conventional ones, such as telephony, facsimile, and telegraph. Demands for digital networks are exploding, not only in terms of quantity but also quality. Nobody can predict where these demands will lead. Traffic engineering, which is impossible in pure Internet protocol (IP) -based networks, is recognized as being indispensable for quality of service (QoS) control. It includes guaranteed services in terms of bandwidth, delay, delay variation (jitter), and service protection. The "engineered tunnel" through IP network supports virtual private networks (VPNs) and allows us to develop voice-over-IP (VoIP), teleconferencing and other secure private network services. This paper proposes the "photonic router" which makes use of wavelength-based networks for signal routing. IP packets having the same destination are bundled into a wavelength path. Interchange nodes along the path route control path routing on the basis of wavelength information, not on IP headers, which can not be read or processed with current optical techniques. In short, wavelength path routing offers "cut-through" in the photonic layer. This paper shows its feasibility by describing the combination of an optical cross-connect, payload assembler/disassembler, label controller, and IP router. Optical cross-connect systems, which are now being intensively studied worldwide, are deemed to be key equipment for a wavelength-path network with centralized control system. This paper proposes to apply the cross-connect to an IP network with distributed autonomous control.

A closed-loop queueing model of flow-based label switches, supporting label reservation protocols of different label-setup and release policies, is presented. This model can emulate the behavior of TCP under the label switch when the maximum window size has been achieved and the packet loss rate is negligible. The label-setup policy is that the IP controller does not start to set up a label until the accumulated packets of the same flow in the switch buffer have exceeded a triggering threshold. Meanwhile, the reserved bandwidth is released when the flow is detected idle and the label-release timer has expired. This policy can achieve higher channel utilization with minimal label processing overhead in spite of suffering from certain delay penalty. To avoid unnecessary TCP timeout or large packet delay under such policy, we also introduce a label-setup timer. Norton's theorem is applied to obtain approximate solutions of this queueing model. Although the analytical method is an approximate one, the simulation results show that the accuracy is high and this model can clearly illustrate how the label-setup and the lable-release timer affect the system performance. Besides, one can observe the trade-off between the throughput and the channel utilization.

This paper proposes and performs the primary feasibility evaluation on Flow Attribute Notification Protocol (FANP), which is a protocol between neighbor CSR (Cell Switch Router) nodes for the management of cut-through packet forwarding, in order to apply label switching paradigm. In cut-through packet forwarding with label switching, a router doesn't have to perform conventional IP packet processing for the received packets. FANP indicates the mapping information between a data-link connection and a packet flow to the neighbor node. FANP defines two key procedures, i. e. , one is the VCID Notification Procedure, and the other is the Flow-ID Notification Procedure. The VCID Notification Procedure lets the label switching paradigm over the label swapped data-link, such as ATM link, though the other label switch architecture can not work over the label swapped data-link. The primary evaluation of FANP has been performed using the prototype system and with the actual packet statistics. The result shows that, with a corporate backbone level, the label switch router system with FANP would work well.