Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563884
A. Morea, J. Poirrier
Translucent optical networks are considered an interesting option for future optical transport networks instead of opaque optical networks. The translucent architecture does not require an OEO conversion at each optical node, but only when the signal is too degraded. Nevertheless a translucent optical network requires higher performance devices, to ensure a minimum number of OEO conversions. In previous studies, translucent optical networks have always proven to be an economically interesting alternative. But the prices of OEO devices have significantly dropped; so down to which point translucent networks are still economically attractive? Asked in another way, up to which point the extra cost of the high performance devices used by translucent networks is lower than the cost of OEO devices in opaque networks? In this paper it is shown that translucent networks, for current traffic volumes, are not yet very attractive; these networks are advantageous for increasing traffic volume and for system reach covering about half of the connection length distribution. Future evolution of system prices is examined to foresee when translucent networks may become economically attractive.
{"title":"A critical analysis of the possible cost savings of translucent networks","authors":"A. Morea, J. Poirrier","doi":"10.1109/DRCN.2005.1563884","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563884","url":null,"abstract":"Translucent optical networks are considered an interesting option for future optical transport networks instead of opaque optical networks. The translucent architecture does not require an OEO conversion at each optical node, but only when the signal is too degraded. Nevertheless a translucent optical network requires higher performance devices, to ensure a minimum number of OEO conversions. In previous studies, translucent optical networks have always proven to be an economically interesting alternative. But the prices of OEO devices have significantly dropped; so down to which point translucent networks are still economically attractive? Asked in another way, up to which point the extra cost of the high performance devices used by translucent networks is lower than the cost of OEO devices in opaque networks? In this paper it is shown that translucent networks, for current traffic volumes, are not yet very attractive; these networks are advantageous for increasing traffic volume and for system reach covering about half of the connection length distribution. Future evolution of system prices is examined to foresee when translucent networks may become economically attractive.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115732883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563879
A. Capello, S. Milani, C. Moriondo, G. Rossi, P. Salamandra, M. Perrone, M. Barone
This document analyzes the "High Availability" feature recently introduced In high-end IP/MPLS equipment. This feature allows, in specific network conditions, IP/MPLS traMc to be forwarded even during temporary unavailability of the Control Plane. The results of lab experiments with High-End IP Routers wm be highlighted. Index Terms IP, MPLS, High Availability, Non Stop Forwarding, Gigarouter, Terarouter, Control Plane.
{"title":"Non-stop forwarding behaviour and performance in high-end IP routers for ISP's backbone networks","authors":"A. Capello, S. Milani, C. Moriondo, G. Rossi, P. Salamandra, M. Perrone, M. Barone","doi":"10.1109/DRCN.2005.1563879","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563879","url":null,"abstract":"This document analyzes the \"High Availability\" feature recently introduced In high-end IP/MPLS equipment. This feature allows, in specific network conditions, IP/MPLS traMc to be forwarded even during temporary unavailability of the Control Plane. The results of lab experiments with High-End IP Routers wm be highlighted. Index Terms IP, MPLS, High Availability, Non Stop Forwarding, Gigarouter, Terarouter, Control Plane.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"231 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116770108","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563842
S. Ruepp, L. Dittman, L. Ellegard
This paper investigates by simulation whether path restoration in a SDH mesh network is more resource effi'cient than traditional protection for a single link failure. The two examined restoration methods are based on the algorithm by Ford and Fulkerson for finding flow augmenting paths, and on the Dijkstra algorithm for finding the shortest path. The methods are studied for two different link upgrading strategies, and for a restoration strategy that adds links to the network. The different methods are compared by simulation with respect to capacity usage, restoration path length (hop count) and number of necessary link upgrades. Our study shows that network restoration can be more resource efficient and requires fewer link upgrades than traditional protection, particularly when applying the Dijkstra method. However, a longer restoration path is required compared to traditional protection. Index Terms path restoration, restoration simulation
{"title":"Simulation and comparison of path restoration techniques in SDH mesh networks","authors":"S. Ruepp, L. Dittman, L. Ellegard","doi":"10.1109/DRCN.2005.1563842","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563842","url":null,"abstract":"This paper investigates by simulation whether path restoration in a SDH mesh network is more resource effi'cient than traditional protection for a single link failure. The two examined restoration methods are based on the algorithm by Ford and Fulkerson for finding flow augmenting paths, and on the Dijkstra algorithm for finding the shortest path. The methods are studied for two different link upgrading strategies, and for a restoration strategy that adds links to the network. The different methods are compared by simulation with respect to capacity usage, restoration path length (hop count) and number of necessary link upgrades. Our study shows that network restoration can be more resource efficient and requires fewer link upgrades than traditional protection, particularly when applying the Dijkstra method. However, a longer restoration path is required compared to traditional protection. Index Terms path restoration, restoration simulation","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"64 4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128369453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563919
J. Farkas, Csaba Antal, Gábor Tóth, L. Westberg
The authors proposed an enhanced resilient Ethernet architecture that is based on multiple pre-established spanning trees to connect a set of edge nodes. Fast failover is achieved so that edge nodes switch to a non-affected tree after a link or node failure. A fast and robust procedure was also proposed for edge nodes to detect failures and notify other edge nodes. The other contribution of the paper is an algorithm that calculates multiple spanning trees for input topologies so that at least one tree provides connectivity after a node or a link failure. The algorithm provides minimal number of spanning trees to make input networks fault tolerant. The performance of the algorithm was tested via simulations.
{"title":"Distributed resilient architecture for Ethernet networks","authors":"J. Farkas, Csaba Antal, Gábor Tóth, L. Westberg","doi":"10.1109/DRCN.2005.1563919","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563919","url":null,"abstract":"The authors proposed an enhanced resilient Ethernet architecture that is based on multiple pre-established spanning trees to connect a set of edge nodes. Fast failover is achieved so that edge nodes switch to a non-affected tree after a link or node failure. A fast and robust procedure was also proposed for edge nodes to detect failures and notify other edge nodes. The other contribution of the paper is an algorithm that calculates multiple spanning trees for input topologies so that at least one tree provides connectivity after a node or a link failure. The algorithm provides minimal number of spanning trees to make input networks fault tolerant. The performance of the algorithm was tested via simulations.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121482670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563915
R. Lent
This paper studies the dynamic discovery of reliable paths by smart packets in ad hoc cognitive packet networks with the aim of supporting robust communications and services. The reliability of nodes is characterized by time-dependent probability variables that packets observe as they move to their destinations. A feedback system allows the distribution of network information to be exploited by future routing decisions to improve or maintain the reliability of paths. Reliability conditions are continuously monitored by packets and a signal is sent to the source node to restart a discovery process whenever a potential risk is detected. Finally, a simulation study reports the resulting performance of a wireless network when smart packets have routing goals based on hop count and reliability-based metrics.
{"title":"Smart packet-based selection of reliable paths in ad hoc networks","authors":"R. Lent","doi":"10.1109/DRCN.2005.1563915","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563915","url":null,"abstract":"This paper studies the dynamic discovery of reliable paths by smart packets in ad hoc cognitive packet networks with the aim of supporting robust communications and services. The reliability of nodes is characterized by time-dependent probability variables that packets observe as they move to their destinations. A feedback system allows the distribution of network information to be exploited by future routing decisions to improve or maintain the reliability of paths. Reliability conditions are continuously monitored by packets and a signal is sent to the source node to restart a discovery process whenever a potential risk is detected. Finally, a simulation study reports the resulting performance of a wireless network when smart packets have routing goals based on hop count and reliability-based metrics.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131239055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563841
Dongmei Wang, Guangzhi Li, R. Doverspike
Multi-Path routing splits a service flow into multiple flow members and each flow member is routed in the network independently. This paper addresses the reliability issues in networks with multi-path routing capability. We provide a novel distributed restoration solution, including the optimal number of service paths and the optimal restoration path based on the total bandwidth requirement. The proposed solution is efficient, scalable, and easy to be implemented in real networks. To assess the quality of the proposed solution, the total bandwidth requirement is first compared between single path routing and multi-path routing. Then the total restoration bandwidth requirement for multi-path routing is compared between disjoint shortest restoration path selection algorithm and the proposed restoration path selection algorithm. Simulation results show that multi-path routing is able to reduce total bandwidth requirement more than 12% than single path routing and the proposed restoration path selection algorithm can further reduce the total restoration bandwidth about 20% on multi-path routing. Index Terms on-line restoration, multi-path routing, distributed algorithm, routing and signalling.
{"title":"On-line restoration for multi-path routing","authors":"Dongmei Wang, Guangzhi Li, R. Doverspike","doi":"10.1109/DRCN.2005.1563841","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563841","url":null,"abstract":"Multi-Path routing splits a service flow into multiple flow members and each flow member is routed in the network independently. This paper addresses the reliability issues in networks with multi-path routing capability. We provide a novel distributed restoration solution, including the optimal number of service paths and the optimal restoration path based on the total bandwidth requirement. The proposed solution is efficient, scalable, and easy to be implemented in real networks. To assess the quality of the proposed solution, the total bandwidth requirement is first compared between single path routing and multi-path routing. Then the total restoration bandwidth requirement for multi-path routing is compared between disjoint shortest restoration path selection algorithm and the proposed restoration path selection algorithm. Simulation results show that multi-path routing is able to reduce total bandwidth requirement more than 12% than single path routing and the proposed restoration path selection algorithm can further reduce the total restoration bandwidth about 20% on multi-path routing. Index Terms on-line restoration, multi-path routing, distributed algorithm, routing and signalling.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130918716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563836
Federico Losego, M. Tornatore, G. Maier, A. Pattavina
Studies concerning G-MPLS based optical networks have often so far neglected the effects of control procedures on the system performance: in path provisioning, in particular, set-up and tear-down of an optical circuit have been modelled as ideal events occurring instantaneously. Actually, the state-of-the-art optical networks are often equipped by semi- or nonautomatic control systems, characterized by manual or temporized procedures. These procedures enforce time constraints in the provisioning of optical circuits. Based on these constraints, in this paper we have classified a set of connection set-up and release policies and we have described how to associate these policies to realistic network control system layouts. Finally we have evaluated the effect on performance of the various policies, applying our control scenarios to the connections offered in two well-known case-study networks. Simulation results are analyzed and commented, keeping our conclusions independent of the specific control system realization and time scale.
{"title":"Time constraints in an OTN semi-automatic control system","authors":"Federico Losego, M. Tornatore, G. Maier, A. Pattavina","doi":"10.1109/DRCN.2005.1563836","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563836","url":null,"abstract":"Studies concerning G-MPLS based optical networks have often so far neglected the effects of control procedures on the system performance: in path provisioning, in particular, set-up and tear-down of an optical circuit have been modelled as ideal events occurring instantaneously. Actually, the state-of-the-art optical networks are often equipped by semi- or nonautomatic control systems, characterized by manual or temporized procedures. These procedures enforce time constraints in the provisioning of optical circuits. Based on these constraints, in this paper we have classified a set of connection set-up and release policies and we have described how to associate these policies to realistic network control system layouts. Finally we have evaluated the effect on performance of the various policies, applying our control scenarios to the connections offered in two well-known case-study networks. Simulation results are analyzed and commented, keeping our conclusions independent of the specific control system realization and time scale.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133114352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563857
R. Andreassen, Aasmund Sudbö, S. Bjornstad, B. Helvik, Erik Hodne, Sigbjörn Wikshaland, E. Zouganeli
This paper presents a study of dependability aspects of a switch architecture for optical burst switching based on tuneable lasers and array waveguide gratings. For this architecture, we carry out analyses of failure modes, alternative fault tolerance schemes and the relation between redundancy dimensioning and the dependability properties one might expect.
{"title":"Fault tolerance in a TWC/AWG based optical burst switching node architecture","authors":"R. Andreassen, Aasmund Sudbö, S. Bjornstad, B. Helvik, Erik Hodne, Sigbjörn Wikshaland, E. Zouganeli","doi":"10.1109/DRCN.2005.1563857","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563857","url":null,"abstract":"This paper presents a study of dependability aspects of a switch architecture for optical burst switching based on tuneable lasers and array waveguide gratings. For this architecture, we carry out analyses of failure modes, alternative fault tolerance schemes and the relation between redundancy dimensioning and the dependability properties one might expect.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114661067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563837
M. Koubàa, N. Puech, M. Gagnaire
Lightpath rerouting is a viable and cost effective solution to improve the network throughput conditioned by the wavelength continuity constraint in all-optical networks. Two traffic classes have been considered referred to as scheduled lightpath demands (SLDs) and random lightpath demands (RLDs). SLDs correspond to high priority traffic whereas RLDs correspond to best effort traffic. An incoming lightpath demand (LD) is rejected when no path-free wavelengths are left in the network to accommodate it. It may happen that by rerouting a certain number of already established LDs, the incoming connection can be set up. In this paper, we propose a new lightpath rerouting algorithm minimizing the amount of rerouted WDM channels. SLD rerouting is forbidden while the establishment of a new RLD may require the rerouting of one or several RLDs. Simulation results show that our algorithm improves the rejection ratio and is less CPU time consuming than rerouting algorithms previously presented in the literature.
{"title":"Lightpath rerouting for differentiated services in WDM all-optical networks","authors":"M. Koubàa, N. Puech, M. Gagnaire","doi":"10.1109/DRCN.2005.1563837","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563837","url":null,"abstract":"Lightpath rerouting is a viable and cost effective solution to improve the network throughput conditioned by the wavelength continuity constraint in all-optical networks. Two traffic classes have been considered referred to as scheduled lightpath demands (SLDs) and random lightpath demands (RLDs). SLDs correspond to high priority traffic whereas RLDs correspond to best effort traffic. An incoming lightpath demand (LD) is rejected when no path-free wavelengths are left in the network to accommodate it. It may happen that by rerouting a certain number of already established LDs, the incoming connection can be set up. In this paper, we propose a new lightpath rerouting algorithm minimizing the amount of rerouted WDM channels. SLD rerouting is forbidden while the establishment of a new RLD may require the rerouting of one or several RLDs. Simulation results show that our algorithm improves the rejection ratio and is less CPU time consuming than rerouting algorithms previously presented in the literature.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115003911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2005-12-27DOI: 10.1109/DRCN.2005.1563880
T. Schwabe, C. Gruber
Demand traffic matrix shifts have a dramatic impact on the required capacity of a network. This paper evaluates the influence of inter-domain failures onto the intra-domain demand traffic matrix. It is observed that some demand matrix values of an autonomous system increase up to 54% (with a 99.5% quantile) for some inter-domain link failures. However, in the evaluated scenarios, an average of 7% additional capacity on intra-domain links were sufficient to route and survive 99.5% of all traffic-shifts that were caused by single inter-domain link failures.
{"title":"Traffic variations caused by inter-domain re-routing","authors":"T. Schwabe, C. Gruber","doi":"10.1109/DRCN.2005.1563880","DOIUrl":"https://doi.org/10.1109/DRCN.2005.1563880","url":null,"abstract":"Demand traffic matrix shifts have a dramatic impact on the required capacity of a network. This paper evaluates the influence of inter-domain failures onto the intra-domain demand traffic matrix. It is observed that some demand matrix values of an autonomous system increase up to 54% (with a 99.5% quantile) for some inter-domain link failures. However, in the evaluated scenarios, an average of 7% additional capacity on intra-domain links were sufficient to route and survive 99.5% of all traffic-shifts that were caused by single inter-domain link failures.","PeriodicalId":415896,"journal":{"name":"DRCN 2005). Proceedings.5th International Workshop on Design of Reliable Communication Networks, 2005.","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117002584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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