In the existing three layers multi-granularity optical switching network based on code group routing entity (CGRE), network nodes can not only achieve the switching of fiber granularity, wavelength granularity, and optical code granularity, but also bundle the associated optical codes into CGRE to transmit in the CGRE pipes. In multi-domain optical networks based on this switching system, the research of routing and optical code allocation is a key point. In the process of optical path establishment and optical codes selection, there is still a phenomenon of network delay and optical code allocation conflict by the traditional serial processing. In order to solve the above problems, based on stateful PCE (Path Computation Element) technology, this paper proposes a strategy for build CGRE pipes (B-CGREP) module and a mechanism for optical code allocation element (OCAE), and introduces the architecture of hierarchical stateful PCE (H-SPCE) in multi-domain network, the architecture consists of a main stateful PCE and multiple sub-stateful PCEs. Add a B-CGREP module to main stateful PCE, and each sub-stateful PCEs is equipped with an OCAE. On the basis of the interaction between the B-CGREP module in the main stateful PCE and the OCAE of each sub-domain, every domain can perform the intra-domain signaling process independently and parallel to achieve fast allocation of cross-domain optical paths and avoid optical code allocation conflicts among domains, as a result, improving the performance of multi-domain intelligent optical networks.
In the existing GMPLS-based distributed control switching network, each network node needs to bear the traffic pressure, not only to calculate the service transmission path, but also to be responsible for data forwarding. In software-defined networking (SDN), the control plane is decoupled from the forwarding plane, which simplifies the network structure and facilitates network maintenance and management. The multi-granularity network is combined with SDN, and the stateful PCE is used as a controller of the network control plane to implement soft control of the network and ensure that the information of the network traffic is controlled in real time. The standard PCEP protocol is extended to add optical code granularity and CGRE (Code Group Routing Entity) related messages, making it suitable for code group switching networks, thereby enabling network services to be transmitted more efficiently and intelligently.
In the traditional multi-granularity switching system, the wavelength is the smallest exchange granularity, but the wavelength granularity is coarse, which is not suitable for small-scale integrated services.Therefore, the optical code packet granularity is introduced, and a three-layer multi-granularity optical cross-connect (MG-OXC) system is established based on optical code division multiplexing (OCDM).Subsequently, the Code Group Routing Entity (CGRE) technology was proposed, which not only improves the utilization of wavelengths, but also reduces the number of ports required for service transmission and reduces network operation costs.In this paper, based on the premise of CGRE technology, a code group routing table is established according to the PCEP general standard and a new code group routing allocation strategy is proposed.The new code group routing allocation strategy can make full use of optical code resources in the wavelength, improve network performance, and reduce network operation costs.
With the growing demand for business communications, electrical signal processing optical path switching can’t meet the demand. The multi-granularity switch system that can improve node routing and switching capabilities came into being. In the traditional network, each node is responsible for calculating the path; synchronize the whole network state, which will increase the burden on the network, so the concept of path calculation element (PCE) is proposed. The PCE is responsible for routing and allocating resources in the network1. In the traditional band-switched optical network, the wavelength is used as the basic routing unit, resulting in relatively low wavelength utilization. Due to the limitation of wavelength continuity, the routing design of the band technology becomes complicated, which directly affects the utilization of the system. In this paper, optical code granularity is adopted. There is no continuity of the optical code, and the number of optical codes is more flexible than the wavelength. For the introduction of optical code switching, we propose a Code Group Routing Entity (CGRE) algorithm. In short, the combination of three-tier multi-granularity optical switching system and PCE can simplify the network structure, reduce the node load, and enhance the network scalability and survivability. Realize the intelligentization of optical network.
At present, as traffic volume which optical transport networks convey and species of traffic grooming methods increase rapidly, optical switching techniques are faced with a series of issues, such as more requests for the number of wavelengths and complicated structure management and implementation. This work introduces optical code switching based on wavelength switching, constructs the three layers multi-granularity optical cross connection (MG-OXC) system on the basis of optical code division multiplexing (OCDM) and presents a new traffic grooming algorithm. The proposed architecture can improve the flexibility of traffic grooming, reduce the amount of used wavelengths and save the number of consumed ports, hence, it can simplify routing device and enhance the performance of the system significantly. Through analyzing the network model of switching structure on multicast layered auxiliary graph (MLAG) and the establishment of traffic grooming links, and the simulation of blocking probability and throughput, this paper shows the excellent performance of this mentioned architecture.
In the existing three layers multi-granularity OCDM switching system (TLMG-OCDMSS), F-LSP, L-LSP and OC-LSP can be bundled as switching granularity. For CPU-intensive network, the node not only needs to compute the path but also needs to bundle the switching granularity so that the load of single node is heavy. The node will paralyze when the traffic of the node is too heavy, which will impact the performance of the whole network seriously. The introduction of stateful PCE(S-PCE) will effectively solve these problems. PCE is composed of two parts, namely, the path computation element and the database (TED and LSPDB), and returns the result of path computation to PCC (path computation clients) after PCC sends the path computation request to it. In this way, the pressure of the distributed path computation in each node is reduced. In this paper, we propose the concept of Learning PCE (L-PCE), which uses the existing LSPDB as the data source of PCE’s learning. By this means, we can simplify the path computation and reduce the network delay, as a result, improving the performance of network.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.