TY - JOUR AU - Szigeti, János AU - Cinkler, Tibor TI - Evaluation and estimation of the availability of p-cycle protected connections JF - TELECOMMUNICATION SYSTEMS J2 - TELECOMMUN SYST VL - 52 PY - 2013 IS - 2 SP - 767 EP - 782 PG - 16 SN - 1018-4864 DO - 10.1007/s11235-011-9576-3 UR - https://m2.mtmt.hu/api/publication/2669470 ID - 2669470 LA - English DB - MTMT ER - TY - CONF AU - Szigeti, János AU - Gordos, Géza AU - Laborczi, Péter TI - Benchmarking of GPS sources for generating traffic information T2 - 16th ITS World Congress and Exhibition on Intelligent Transport Systems and Services PY - 2011 SP - 1 EP - 7 PG - 7 UR - https://m2.mtmt.hu/api/publication/2694730 ID - 2694730 N1 - cikk száma 3739 LA - English DB - MTMT ER - TY - CONF AU - Szigeti, János AU - Cinkler, Tibor TI - Inaccuracy of the Serial-Parallel Availability Estimation Method T2 - RNDM 2010 - 2nd International Worskhop on Reliable Networks Design and Modeling PY - 2010 SP - 615 EP - 621 PG - 7 DO - 10.1109/ICUMT.2010.5676573 UR - https://m2.mtmt.hu/api/publication/2662395 ID - 2662395 N1 - Export Date: 7 December 2023 Correspondence Address: Szigeti, J.; High-Speed Networks Laboratory, Magyar tudósok krt 2, H-1117 Budapest, Hungary; email: szigeti@tmit.bme.hu AB - Provisioning QoS network connections with the desired availability relies on estimating the availability of the connections in advance. The redundancy of the protection - which denotes how many failures can be survived - gives a good hint on the availability, thus lower bound estimation can be carried out. If we want to achieve a more accurate approximation, we have to use other methods. The Serial-Parallel availability modeling and calculation method, based on the availability metrics of the components of the connection, offers a fast estimation, with the complexity of O(n) in case of n components. However, the result of this estimation can be inaccurate since the model does not take into account the overlapping of components, i.e., when a component is member of more different series. In this paper we analyze the inaccuracy of the Serial-Parallel method. We prove that the estimated availability is always less than the exact one, define an upper bound onto the inaccuracy of the estimated unavailability and show where does this inaccuracy converge by increasing the availability of the network components. LA - English DB - MTMT ER - TY - JOUR AU - Szigeti, János AU - Romeral, R. AU - Cinkler, Tibor AU - Larrabeiti, D. TI - P-cycle Protection in multi-domain optical networks JF - PHOTONIC NETWORK COMMUNICATIONS J2 - PHOTONIC NETW COMMUN VL - 17 PY - 2009 IS - 1 SP - 35 EP - 47 PG - 13 SN - 1387-974X DO - 10.1007/s11107-008-0141-2 UR - https://m2.mtmt.hu/api/publication/32643781 ID - 32643781 N1 - Department of Telecommunications and Media Informatics, High-Speed Networks Laboratory, Budapest University of Technology and Economics, Magyar tudósok krt. 2, 1117 Budapest, Hungary Department of Telematic Engineering, Carlos III University of Madrid, Leganes 28911, Spain Cited By :16 Export Date: 3 February 2022 Correspondence Address: Szigeti, J.; Department of Telecommunications and Media Informatics, Magyar tudósok krt. 2, 1117 Budapest, Hungary; email: szigeti@tmit.bme.hu Funding details: TSI2005-07384-C03-02 Funding details: Seventh Framework Programme, FP7, 216863 Funding details: European Commission, EC Funding text 1: Optical Network in Europe”), a Network of Excellence funded by the European Commission through the 7th ICT-Framework Programme, e-Photon/ONe+ and Spanish grant TSI2005-07384-C03-02. Many thanks to the LEMON-team (http://lemon.cs.elte.hu) for developing and providing their excellent graph template library to accelerate our simulations. AB - 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. © 2008 Springer Science+Business Media, LLC. LA - English DB - MTMT ER - TY - CONF AU - Szigeti, János AU - Laborczi, Péter AU - Gordos, Géza TI - Benchmarking of Floating Car Data Sources T2 - 16th ITS World Congress and Exhibition on Intelligent Transport Systems and Services PB - ERTICO ITS Europe C1 - Brüsszel PY - 2009 UR - https://m2.mtmt.hu/api/publication/2669469 ID - 2669469 AB - Most Floating Car Data (FCD) systems use data of fleet management companies to monitor the currents state of traffic. However, the original task of these systems (e.g., tracking positions and status of taxis or protecting vehicles) are different from measuring travel times. Consequently, it is important to measure the ``quality'' of a given fleet from the Floating Car Data point of view. Usually, the number of vehicles and the mean time between two measurements is used to assess the quality of the data but these numbers are misleading in many cases. Other approach would be to carry out the whole process until travel time estimation and compare the resulting travel times with other sources. This process is very time consuming and cannot be carried out because of lack of data in most cases. FCD source benchmarking method -- proposed in this paper -- is a simple way of estimating, monitoring and comparison of different data sources. The inputs of the method are the data sets only, not even the digital map is needed. The method proved to be efficient in a Floating Car Data project in Budapest. LA - English DB - MTMT ER - TY - JOUR AU - Callegati, Franco AU - Cugini, Filippo AU - Ghobril, Paul AU - Gunreben, Sebastian AU - López, V AU - Martini, Barbara AU - Marińo, Pablo Pavón AU - Perényi, Marcell Ádám AU - Szigeti, János AU - Segovia, Juan AU - Staessens, Dimitri AU - Sengezer, Namik AU - Tornatore, Massimo TI - Optical core networks research in the e-photon-one project JF - JOURNAL OF LIGHTWAVE TECHNOLOGY J2 - J LIGHTWAVE TECHNOL VL - 27 PY - 2009 IS - 20 SP - 4415 EP - 4423 PG - 9 SN - 0733-8724 DO - 10.1109/JLT.2009.2024090 UR - https://m2.mtmt.hu/api/publication/2645131 ID - 2645131 AB - This paper reports a summary of the joint research activities on Optical Core Networks within the e-Photon-ONe project. It provides a reasonable overview of the topics considered of interest by the European research community and supports the idea of building joint research activities that can leverage on the expertise of different research groups. LA - English DB - MTMT ER - TY - CHAP AU - Szigeti, János AU - Cinkler, Tibor AU - Romeral, Ricardo ED - IEEE, null TI - Rule-Based Topology Advertisement Supporting Generalized Protection T2 - ONDM PB - IEEE Press CY - New York, New York SN - 9781424441877 PY - 2009 SP - 129 EP - 135 PG - 7 UR - https://m2.mtmt.hu/api/publication/2639327 ID - 2639327 N1 - High-Speed Networks Laboratory, Department of Telecommunications and Media Informatics, Budapest University of Technology and Economics, Magyar tudósok kit. 2, H-1117, Budapest, Hungary Department of Telematic Engineering, Carlos III University of Madrid, Leganés, 28911, Spain Conference code: 79803 Export Date: 3 February 2022 Correspondence Address: Szigeti, J.; High-Speed Networks Laboratory, Magyar tudósok kit. 2, H-1117, Budapest, Hungary; email: szigeti@tmit.bme.hu AB - Routing in multilayer optical networks can be made efficient if Label Switched Paths are searched in a Wavelength Graph that represents the state and the switching facilities of the network devices very accurately. Maintaining the Wavelength Graph by using the conventional Link State Advertisement control mechanism leads to scalability problem. Much of the link state information is, however, redundant as the set of state changes triggered by a single resource allocation or release are in correlation. By introducing a rule-based topology advertisement and maintenance method, the amount of control messages can be significantly reduced without deteriorating the quality of routing. This paper proposes an extension to the method to be able to handle various protection schemes in the network simultaneously. Although the proposed method is primarily developed for optical networks and Wavelength Graphs it can be applied efficiently also onto pure MPLS networks. LA - English DB - MTMT ER - TY - CHAP AU - Cinkler, Tibor AU - Hegyi, Péter AU - Geleji, Géza AU - Szigeti, János AU - Ladányi, Ákos ED - IEEE, Communication Society TI - Adaptive Multi-Layer Traffic Engineering with Shared Risk Group Protection T2 - 2008 IEEE International Conference on Communications, Vols 1-13 PB - IEEE CY - Piscataway (NJ) SN - 9781424420759 T3 - IEEE International Conference on Communications, ISSN 1550-3607 PY - 2008 SP - 5367 EP - 5371 PG - 5 DO - 10.1109/ICC.2008.1006 UR - https://m2.mtmt.hu/api/publication/2618027 ID - 2618027 N1 - Export Date: 9 January 2024 Correspondence Address: Cinkler, T.; High-Speed Networks Laboratory, , Budapest, Hungary; email: cinkler@tmit.bme.hu LA - English DB - MTMT ER - TY - JOUR AU - Szigeti, János AU - Gyarmati, László AU - Cinkler, Tibor TI - Multidomain shared protection with limited information via MPP and p-cycles JF - JOURNAL OF OPTICAL NETWORKING J2 - J OPT NETW VL - 7 PY - 2008 IS - 5 SP - 400 EP - 409 PG - 10 SN - 1536-5379 DO - 10.1364/JON.7.000400 UR - https://m2.mtmt.hu/api/publication/1789125 ID - 1789125 N1 - Cited By :5 Export Date: 28 May 2020 Correspondence Address: Cinkler, T.; Department of Telecommunications and Media Informatics, High Speed Networking Laboratory, Budapest University of Technology and Economics, Magyar Tudósok Kõrútja 2, H-1117 Budapest, Hungary; email: cinkler@tmit.bme.hu AB - The internet consists of a collection of more than 21,000 domains called autonomous systems operated mostly under different authorities (operators?providers) that, although they cooperate over different geographical areas, compete in a country or other area. Recently, the path computation element concept has been proposed to generalized multiprotocol label switching controlled optical board networks to make routing decisions for interdomain connections taking into account traffic engineering, quality of service and resilience considerations. Still the question of protection shareability emerges. For dedicated protection it is enough to know the topology of the network to be able to calculate disjoint paths. However, to reduce network resource usage by sharing of protection resources (e.g., end-to-end shared protection) it is also mandatory to know the exact working and protection path pairs for all the demands. This can be checked within a domain where not only the full topology and link-state information is flooded but also the working and protection paths are known for each connection; however; over the domain boundaries for security and scalability reasons no such information is being spread. We propose using two techniques that do not require flooding the information on working and protection paths while still allowing the sharing of resources. These two techniques are the multidomain p-cycles and the multidomain multipath routing with protection. After explaining the principles of these methods we evaluate the trade-off between the resource requirement and availability of these techniques by simulations. LA - English DB - MTMT ER - TY - CHAP AU - Szigeti, János AU - Cinkler, Tibor ED - IEEE, null TI - Incremental availability evaluation model for p-cycle protected connections T2 - DRCN 2007, 6th International Workshop on the Design of Reliable Communication Networks PB - IEEE Press CY - New York, New York SN - 1424438241 PY - 2007 PG - 8 DO - 10.1109/DRCN.2007.4762278 UR - https://m2.mtmt.hu/api/publication/32643789 ID - 32643789 N1 - Conference code: 75772 Cited By :4 Export Date: 3 February 2022 Correspondence Address: Szigeti, J.; High-Speed Networks Laboratory, Magyar tudósok krt 2, H-1117 Budapest, Hungary; email: szigeti@tmit.bme.hu AB - QoS routes need availability assurance. Regardless of the applied protection scheme, there are several heuristic algorithms that can approximate the availability of connections based on the availability parameters of network components along the connection path. Accurate approximation can be achieved with simple and fast calculation only for the most basic protection schemes, the more complex the protection scheme is the more complex and long running calculation is required to get the result. Though, the inaccuracy of the heuristic algorithms is negligible in the most cases of practical usage. In this paper we present an availability calculation method for p-cycles that exploits the special properties of the p-cycle protection scheme and provides accurate results without enumerating all the possible network or protection configuration states. The method evaluates the availability of the connection along the working path link-by-link incrementally, pre-calculating also those conditional availabilities of the connection-part that may be used in latter calculations. Theoretically, the complexity of the algorithm is still O(2n), however, in fact n does not get high, moreover, it can be kept moderate low if the size of the cycles is constrained. LA - English DB - MTMT ER -