共查询到10条相似文献,搜索用时 171 毫秒
1.
Optical fiber networks have become the foundations of communication system to provide enormous transmission capacity with less cost. Connection blocking is an inherent attribute and influences optical networks’ performance, especially in multi-domain network scenarios. We analyze the reason and effect of blockings including routing blockings and signaling blockings. We regard the cause of signaling blockings as the information asynchronization in resource reservation process. We define the concept of Information Asynchronization Period to describe the effect of signaling blockings. To reduce signaling blockings in end-to-end optical path provisioning for multi-domain scenarios, we propose a novel network routing and control scheme, named Intra-Domain Immediate Reroute based Semi-Proactive Hierarchical Path Computation Element (IDIRSP H-PCE). The proposed routing and control scheme mainly consists of two parts, Semi-Proactive routing and Intra-Domain Immediate Reroute mechanism. Dynamic network simulations verify our proposed scheme. We compare the network performance with Reactive Backward Recursive PCE-based Computation (BRPC) based PCE, Reactive H-PCE and Proactive H-PCE. Simulation results indicate that IDIRSP H-PCE can provide connection with a very low blocking probability in light load case, which is close to Proactive H-PCE, and obviously better than BRPC based Reactive PCE and Reactive H-PCE. For heavy load case, IDIRSP H-PCE has a remarkably lower blocking probability than other three methods. Moreover, we test our proposed routing and control scheme when facing link faults. Simulation results indicate that IDIRSP H-PCE can greatly improve the traffic access rate and optimize the network performance. 相似文献
2.
Shengfeng Zhang Shu Du Yunfeng Peng Xiaolong Yang Keping Long 《Photonic Network Communications》2011,22(3):276-287
Survivability has been widely recognized as an important design issue for optical networks. In practice, as the network scale
keeps expanding, this design problem becomes more critical. Due to scalability and domain privacy, designing the protection
scheme in multi-domain networks is more difficult than that in single domain networks. The path computation element (PCE)
is known as an efficient architecture to compute optimal traffic engineering (TE) paths in multi-domain multilayer networks.
Based on the PCE architecture, we first propose a new dynamic domain-sequencing scheme that considers the load balance of
inter-domain links and then propose an improved segment-shared protection approach called DDSP. It can provide 100% protection
ability for multiple failures that each single domain has only one failed link. Finally, the protection based on the optimal
dynamic domain-sequencing scheme, called OPT, is designed, to evaluate performance of our algorithm and to provide the good
bounding for the dynamic domain-sequencing scheme with limited intra TE information. Simulation evaluation shows that the
proposed scheme is effective in multi-domain path protection with more efficient resource utilization, lower blocking probabilities
and less inter-domain cost. Furthermore, the performance of it is near to OPT. 相似文献
3.
4.
Wajdi Halabi Kris Steenhaut Marnix Goossens Thu-Huong Truong Ann Nowé 《Photonic Network Communications》2012,23(3):217-229
Routing, connection setup, and path computation are well-known problems in multi-domain networks, which have been largely
analyzed in pure IP (packet) networks. In circuit-switched optical multi-domain networks, there remain, however, a number
of routing and path computation challenges. Traffic grooming means combining a number of low-speed traffic streams so that
the high capacity of each lightpath may be used as efficiently as possible, as path computation implements the core of the
grooming function, it is obvious that solutions for the traffic grooming problem in optical multi-domain networks are still
not sufficiently investigated. In this study we propose a methodology to address the problems of routing, connection setup,
and traffic grooming in optical multi-domain networks, which adapts a two-level hierarchical routing scheme and full-mesh
topology abstraction algorithm to improve routing scalability and lower inter-domain blocking probabilities; additionally
our proposed methodology adapts a scheme for traffic grooming in DWDM multi-domain networks to improve the resources usage.
To test our proposed methodology we propose a detailed IP/MPLS-based ASON/GMPLS multi-domain multilayer test framework. 相似文献
5.
Lei Guo Xingwei Wang Ying Li Chongshan Wang Hongming Li Hongpeng Wang Xin Liu 《Optical Fiber Technology》2009,15(2):192-196
In multi-domain wavelength-division-multiplexing (WDM) optical networks, the inter-domain routing is a challenge since each single-domain cannot view the full network topology. At the same time, survivability is also an important issue in optical networks since the failures of fiber links or network nodes may lead to a lot of traffic being blocked. In this paper, we study the survivability in multi-domain WDM optical networks, and propose a new survivable mechanism called load balanced domain-by-domain routing (LBDDR). In LBDDR, in order to obtain the efficient inter-domain survivable routes, we present the domain-by-domain routing (DDR) method which can find the intra-domain sub-working path and sub-backup path in each single-domain to form the inter-domain working path and backup path for each demand. In order to reduce the blocking probability, we present the load balanced routing method which can encourage the traffic to be uniformly distributed on the links with more free wavelengths. Simulation results show that, compared with conventional mechanism, LBDDR can obtain better performances. 相似文献
6.
Software-defined networking (SDN) scheme decouples network control plane and data plane, which can improve the flexibility of traffic management in networks. OpenFlow is a promising implementation instance of SDN scheme and has been applied to enterprise networks and data center networks in practice. However, it has less effort to spread SDN control scheme over the Internet to conquer the ossification of inter-domain routing. In this paper, we further innovate to the SDN inter-domain routing inspired by the OpenFlow protocol. We apply SDN flow-based routing control to inter-domain routing and propose a fine-granularity inter-domain routing mechanism, named SDI (Software Defined Inter-domain routing). It enables inter-domain routing to support the flexible routing policy by matching multiple fields of IP packet header. We also propose a method to reduce redundant flow entries for inter-domain settings. And, we implement a prototype and deploy it on a multi-domain testbed. 相似文献
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Guillem Hernández-Sola Jordi Perelló Fernando Agraz Luis Velasco Salvatore Spadaro Gabriel Junyent 《Photonic Network Communications》2011,21(2):141-151
The ability of computing optimal routes poses new challenges when extending it to larger multi-domain network scenarios, as
the quality of these computed end-to-end inter-domain routes depends on the selection of the domain sequence to be traversed.
In the scope of the Internet Engineering Task Force (IETF), the Path Computation Element (PCE) Working Group has not provided
definitive solutions to address the domain sequence selection problem, being still a work in progress. To this goal, the Path
Computation Flooding (PCF) approach appears as a possible extension to Backward Recursive PCE-based Computation (BRPC) to
calculate optimal end-to-end inter-domain paths without requiring a pre-configured domain sequence. Nonetheless, PCF presents
major scalability issues in terms of network control overhead and path computation complexity, thus pleading for more accurate
domain sequence selection techniques. This paper describes two novel mechanisms to establish inter-domain paths calculating
the sequence of domains to be crossed when it is not known in advance. Both procedures make a good trade-off between the control
overhead introduced and the accuracy of the computed end-to-end route. The obtained simulation results show the benefits of
the proposed contributions, drastically reducing the control overhead while keeping the connection blocking probability close
to the optimal values. 相似文献
9.
Although multi-domain survivability is a major concern for operators, few studies have considered the design of post-fault restoration schemes. This paper proposes two such strategies, based upon hierarchical routing and signaling crankback, to handle single and multi-link failure events in multi-domain IP/MPLS networks (also extendible to optical DWDM networks). Specifically, the hierarchical routing strategy relies upon abstracted domain information to compute inter-domain loose routes, whereas the crankback scheme applies signaling re-tries to restore paths in a domain-by-domain manner. The performance of these proposed solutions is then analyzed and compared via simulation. 相似文献
10.
János Szigeti Ricardo Romeral Tibor Cinkler David Larrabeiti 《Photonic Network Communications》2009,17(1):35-47
Providing resilient inter-domain connections in multi-domain optical GMPLS networks is a challenge. On the one hand, the integration
of different GMPLS domains to run traffic engineering operations requires the development of a framework for inter-domain
routing and control of connections, while keeping the internal structure and available resources of the domains undisclosed
to the other operators. On the other hand, the definition of mechanisms to take advantage of such automatically switched inter-domain
connectivity is still an open issue. This article focuses on the analysis of applicability of one of these mechanisms: P-cycle-based protection. The proposed solution is based on the decomposition of the multi-domain resilience problem into two
sub-problems, namely, the higher level inter-domain protection and the lower level intra-domain protection. Building a P-cycle at the higher level is accomplished by certain tasks at the lower level, including straddling link connection, capacity
allocation and path selection. In this article, we present several methods to realize inter-domain P-cycle protection at both levels and we evaluate their performance in terms of availability and spent resources. A discussion
on a proposal of implementation of signalling based on extensions of existing protocols such as RSVP-TE and the PCE architecture
illustrates the practical viability of the approach.
相似文献
David LarrabeitiEmail: |