Pub Date : 2009-06-01DOI: 10.1109/INM.2009.5188846
Alvaro Coelho, F. Brasileiro, P. D. Maciel
In this paper we consider a peer-to-peer grid system which provides multiple services to its users. An incentive mechanism promotes collaboration among peers. It has been shown that the use of a reciprocation-based incentive mechanism in such a system prevents free-riding and, at the same time, promotes the clustering of peers that have mutually profitable interactions. On the other hand, an issue that has not been sufficiently studied in this context is that of service portfolio selection. Normally, peers are subject to resource limitations, which force them to provide only a subset of all services that can be possibly provided. Clearly, the subset of selected services impacts the profit that the grid yields to the peers, since each service will have a different cost and will return a different utility. Moreover, the utility generated by a service is strongly influenced by the behavior of the other peers, which in turn may change over time. In this paper we explore the use of heuristics to select the portfolio of services to be offered by peers in such a grid. The main contributions of this work are the use of heuristics to improve the average profit of peers and a study on the impact of some system characteristics on the heuristics behavior.
{"title":"Using heuristics to improve service portfolio selection in P2P grids","authors":"Alvaro Coelho, F. Brasileiro, P. D. Maciel","doi":"10.1109/INM.2009.5188846","DOIUrl":"https://doi.org/10.1109/INM.2009.5188846","url":null,"abstract":"In this paper we consider a peer-to-peer grid system which provides multiple services to its users. An incentive mechanism promotes collaboration among peers. It has been shown that the use of a reciprocation-based incentive mechanism in such a system prevents free-riding and, at the same time, promotes the clustering of peers that have mutually profitable interactions. On the other hand, an issue that has not been sufficiently studied in this context is that of service portfolio selection. Normally, peers are subject to resource limitations, which force them to provide only a subset of all services that can be possibly provided. Clearly, the subset of selected services impacts the profit that the grid yields to the peers, since each service will have a different cost and will return a different utility. Moreover, the utility generated by a service is strongly influenced by the behavior of the other peers, which in turn may change over time. In this paper we explore the use of heuristics to select the portfolio of services to be offered by peers in such a grid. The main contributions of this work are the use of heuristics to improve the average profit of peers and a study on the impact of some system characteristics on the heuristics behavior.","PeriodicalId":332206,"journal":{"name":"2009 IFIP/IEEE International Symposium on Integrated Network Management","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123784430","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 : 2009-06-01DOI: 10.1109/INM.2009.5188889
S. Davy, B. Jennings, J. Strassner
We present a policy conflict analysis process that makes use of pre-defined semantic models of an application to perform effective and efficient conflict analysis. The process is effective as it can be used to analyse for policy conflicts that may occur in different applications due to the separation of application specific information and constraints from the algorithms to semantic models, such as information model and ontologies. The process is efficient as it incorporates a pre-analysis policy selection step that reduces the number of policies that need to be analysed more extensively. Experimental results show that this process results in a significant reduction in the number of policies that needed to be analysed for potential conflict and that it is flexible enough to detect for policy conflict both for many popular applications and between different applications.
{"title":"On harnessing information models and ontologies for policy conflict analysis","authors":"S. Davy, B. Jennings, J. Strassner","doi":"10.1109/INM.2009.5188889","DOIUrl":"https://doi.org/10.1109/INM.2009.5188889","url":null,"abstract":"We present a policy conflict analysis process that makes use of pre-defined semantic models of an application to perform effective and efficient conflict analysis. The process is effective as it can be used to analyse for policy conflicts that may occur in different applications due to the separation of application specific information and constraints from the algorithms to semantic models, such as information model and ontologies. The process is efficient as it incorporates a pre-analysis policy selection step that reduces the number of policies that need to be analysed more extensively. Experimental results show that this process results in a significant reduction in the number of policies that needed to be analysed for potential conflict and that it is flexible enough to detect for policy conflict both for many popular applications and between different applications.","PeriodicalId":332206,"journal":{"name":"2009 IFIP/IEEE International Symposium on Integrated Network Management","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115509963","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 : 2009-06-01DOI: 10.1109/INM.2009.5188856
S. García-Jiménez, E. Magaña, D. Morató, M. Izal
One of the challenging problems related with network topology discovery in Internet is the process of IP address alias identification. Topology information is usually obtained from a set of traceroutes that provide IP addresses of routers in the path from a source to a destination. If these traceroutes are repeated between several source/destination pairs we can get a sampling of all IP addresses for crossed routers. In order to generate the topology graph in which each router is a node, it is needed to identify all IP addresses that belong to the same router. In this work we propose improvements over existing methods to obtain alias identification related mainly with the types and options in probing packets.
{"title":"Techniques for better alias resolution in Internet topology discovery","authors":"S. García-Jiménez, E. Magaña, D. Morató, M. Izal","doi":"10.1109/INM.2009.5188856","DOIUrl":"https://doi.org/10.1109/INM.2009.5188856","url":null,"abstract":"One of the challenging problems related with network topology discovery in Internet is the process of IP address alias identification. Topology information is usually obtained from a set of traceroutes that provide IP addresses of routers in the path from a source to a destination. If these traceroutes are repeated between several source/destination pairs we can get a sampling of all IP addresses for crossed routers. In order to generate the topology graph in which each router is a node, it is needed to identify all IP addresses that belong to the same router. In this work we propose improvements over existing methods to obtain alias identification related mainly with the types and options in probing packets.","PeriodicalId":332206,"journal":{"name":"2009 IFIP/IEEE International Symposium on Integrated Network Management","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128279056","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 : 2009-06-01DOI: 10.1109/INM.2009.5188783
M. Brunner, D. Dudkowski, C. Mingardi, G. Nunzi
This work proposes a probabilistic management paradigm for solving some major challenges of decentralized network management. Specifically, we show how to cope with 1) the overhead of redundant information gathering and processing, 2) the decentralized management in dynamic and unpredictable environments, and 3) the considerable effort required for decentralized coordination of management functions. To this end, we describe a framework for probabilistic decentralized management in the context of In-Network Management (INM). We demonstrate how this framework can be applied to a network of information, a novel clean-slate approach towards an information-centric future Internet. We show by means of a simulation study in the area of performance and fault management that we can significantly reduce the effort and resources dedicated to management, while we are able to achieve a sound level of accuracy of the overall network view.
{"title":"Probabilistic decentralized network management","authors":"M. Brunner, D. Dudkowski, C. Mingardi, G. Nunzi","doi":"10.1109/INM.2009.5188783","DOIUrl":"https://doi.org/10.1109/INM.2009.5188783","url":null,"abstract":"This work proposes a probabilistic management paradigm for solving some major challenges of decentralized network management. Specifically, we show how to cope with 1) the overhead of redundant information gathering and processing, 2) the decentralized management in dynamic and unpredictable environments, and 3) the considerable effort required for decentralized coordination of management functions. To this end, we describe a framework for probabilistic decentralized management in the context of In-Network Management (INM). We demonstrate how this framework can be applied to a network of information, a novel clean-slate approach towards an information-centric future Internet. We show by means of a simulation study in the area of performance and fault management that we can significantly reduce the effort and resources dedicated to management, while we are able to achieve a sound level of accuracy of the overall network view.","PeriodicalId":332206,"journal":{"name":"2009 IFIP/IEEE International Symposium on Integrated Network Management","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126662797","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 : 2009-06-01DOI: 10.1109/INM.2009.5188786
Arlindo L. Marcon, A. Santin, L. Lima, R. Obelheiro, Maicon Stihler
The decentralization of corporate policy administration aiming to maintain the unified management of user permissions is a hard task. The heterogeneity and complexity of corporate environments burdens the security administrator with writing equally complex policies. This paper proposes an architecture based on Web Services, policy provisioning, and authorization certificates, to build up a loosely coupled unified administrative control for corporate environments. A certificate-based permission management scheme is used to derive new policies in the local domains of each branch. These new policies will update the corporate repository which, in turn, will configure the corresponding policies in the local domains of each branch. The Web Services technology provides the underlying protocols for the development of a prototype which shows the feasibility of our proposal.
{"title":"Policy control management for Web Services","authors":"Arlindo L. Marcon, A. Santin, L. Lima, R. Obelheiro, Maicon Stihler","doi":"10.1109/INM.2009.5188786","DOIUrl":"https://doi.org/10.1109/INM.2009.5188786","url":null,"abstract":"The decentralization of corporate policy administration aiming to maintain the unified management of user permissions is a hard task. The heterogeneity and complexity of corporate environments burdens the security administrator with writing equally complex policies. This paper proposes an architecture based on Web Services, policy provisioning, and authorization certificates, to build up a loosely coupled unified administrative control for corporate environments. A certificate-based permission management scheme is used to derive new policies in the local domains of each branch. These new policies will update the corporate repository which, in turn, will configure the corresponding policies in the local domains of each branch. The Web Services technology provides the underlying protocols for the development of a prototype which shows the feasibility of our proposal.","PeriodicalId":332206,"journal":{"name":"2009 IFIP/IEEE International Symposium on Integrated Network Management","volume":"37 10","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120998832","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 : 2009-06-01DOI: 10.1109/INM.2009.5188843
J. Famaey, W. D. Cock, T. Wauters, F. Turck, B. Dhoedt, P. Demeester
A generic and self-managing service hosting infrastructure, provides a means to offer a large variety of services to users across the Internet. Such an infrastructure provides mechanisms to automatically allocate resources to services, discover the location of these services, and route client requests to a suitable service instance.
{"title":"A latency-aware algorithm for dynamic service placement in large-scale overlays","authors":"J. Famaey, W. D. Cock, T. Wauters, F. Turck, B. Dhoedt, P. Demeester","doi":"10.1109/INM.2009.5188843","DOIUrl":"https://doi.org/10.1109/INM.2009.5188843","url":null,"abstract":"A generic and self-managing service hosting infrastructure, provides a means to offer a large variety of services to users across the Internet. Such an infrastructure provides mechanisms to automatically allocate resources to services, discover the location of these services, and route client requests to a suitable service instance.","PeriodicalId":332206,"journal":{"name":"2009 IFIP/IEEE International Symposium on Integrated Network Management","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114812070","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 : 2009-06-01DOI: 10.1109/INM.2009.5188781
C. Bartolini, C. Stefanelli, M. Tortonesi
Service disruptions can have a considerable impact on business operations of IT support organizations, thus calling for the implementation of efficient incident management and service restoration processes. The evaluation and improvement of incident management strategies currently in place, in order to minimize the business-impact of major service disruptions, is a very arduous task which goes beyond the optimization with respect to IT-level metrics. This paper presents HANNIBAL, a decision support tool for the business impact analysis and improvement of the incident management process. HANNIBAL evaluates possible strategies for an IT support organization to deal with major service disruptions. HANNIBAL then selects the strategy with the best alignment to the business objectives. Experimental results collected from the HANNIBAL application to a realistic case study show that business impact-driven optimization outperforms traditional performance-driven optimization.
{"title":"Business-impact analysis and simulation of critical incidents in IT service management","authors":"C. Bartolini, C. Stefanelli, M. Tortonesi","doi":"10.1109/INM.2009.5188781","DOIUrl":"https://doi.org/10.1109/INM.2009.5188781","url":null,"abstract":"Service disruptions can have a considerable impact on business operations of IT support organizations, thus calling for the implementation of efficient incident management and service restoration processes. The evaluation and improvement of incident management strategies currently in place, in order to minimize the business-impact of major service disruptions, is a very arduous task which goes beyond the optimization with respect to IT-level metrics. This paper presents HANNIBAL, a decision support tool for the business impact analysis and improvement of the incident management process. HANNIBAL evaluates possible strategies for an IT support organization to deal with major service disruptions. HANNIBAL then selects the strategy with the best alignment to the business objectives. Experimental results collected from the HANNIBAL application to a realistic case study show that business impact-driven optimization outperforms traditional performance-driven optimization.","PeriodicalId":332206,"journal":{"name":"2009 IFIP/IEEE International Symposium on Integrated Network Management","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125444090","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 : 2009-06-01DOI: 10.1109/INM.2009.5188782
Joel W. Branch, C. Bisdikian, Starsky H. Y. Wong, D. Agrawal
In this paper, a novel procedural framework for increasing the efficiency of the model composition process for the end-to-end transactional behavior of various classes of business-level computer applications is presented. The objectives of the framework are reducing the composition time and the level of engagement of domain experts in deploying business management solutions. Starting with application footprints (i.e., raw log data of various types) and without the need for a priori understanding of their syntax and semantics, the framework permits the analysis of the footprints based on an agnostic tokenization of log data. The framework then produces candidate states and relationships that form the basis for composing the transactional models via the framework's state and relationship manipulation utilities. The main architectural components of the framework are presented and their underlying principles discussed. A case study highlighting the use of the framework, based on an implementation of it, is given and a discussion regarding additional features of the framework and its relation to other research activities is also provided.
{"title":"A universal method for composing business transaction models using logs","authors":"Joel W. Branch, C. Bisdikian, Starsky H. Y. Wong, D. Agrawal","doi":"10.1109/INM.2009.5188782","DOIUrl":"https://doi.org/10.1109/INM.2009.5188782","url":null,"abstract":"In this paper, a novel procedural framework for increasing the efficiency of the model composition process for the end-to-end transactional behavior of various classes of business-level computer applications is presented. The objectives of the framework are reducing the composition time and the level of engagement of domain experts in deploying business management solutions. Starting with application footprints (i.e., raw log data of various types) and without the need for a priori understanding of their syntax and semantics, the framework permits the analysis of the footprints based on an agnostic tokenization of log data. The framework then produces candidate states and relationships that form the basis for composing the transactional models via the framework's state and relationship manipulation utilities. The main architectural components of the framework are presented and their underlying principles discussed. A case study highlighting the use of the framework, based on an implementation of it, is given and a discussion regarding additional features of the framework and its relation to other research activities is also provided.","PeriodicalId":332206,"journal":{"name":"2009 IFIP/IEEE International Symposium on Integrated Network Management","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132456913","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 : 2009-06-01DOI: 10.1109/inm.2009.5188818
F. Wuhib, R. Stadler, M. Dam
We investigate the use of gossip protocols to detect threshold crossings of network-wide aggregates. Aggregates are computed from local device variables using functions such as SUM, AVERAGE, COUNT, MAX and MIN. The process of aggregation and detection is performed using a standard gossiping scheme. A key design element is to let nodes dynamically adjust their neighbor interaction rates according to the distance between the nodes' local estimate of the global aggregate and the threshold itself. We show that this allows considerable savings in communication overhead. In particular, the overhead becomes negligible when the aggregate is sufficiently far above or far below the threshold. We present evaluation results from simulation studies regarding protocol efficiency, quality of threshold detection, scalability, and controllability.
{"title":"Gossiping for threshold detection","authors":"F. Wuhib, R. Stadler, M. Dam","doi":"10.1109/inm.2009.5188818","DOIUrl":"https://doi.org/10.1109/inm.2009.5188818","url":null,"abstract":"We investigate the use of gossip protocols to detect threshold crossings of network-wide aggregates. Aggregates are computed from local device variables using functions such as SUM, AVERAGE, COUNT, MAX and MIN. The process of aggregation and detection is performed using a standard gossiping scheme. A key design element is to let nodes dynamically adjust their neighbor interaction rates according to the distance between the nodes' local estimate of the global aggregate and the threshold itself. We show that this allows considerable savings in communication overhead. In particular, the overhead becomes negligible when the aggregate is sufficiently far above or far below the threshold. We present evaluation results from simulation studies regarding protocol efficiency, quality of threshold detection, scalability, and controllability.","PeriodicalId":332206,"journal":{"name":"2009 IFIP/IEEE International Symposium on Integrated Network Management","volume":"42 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131076585","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 : 2009-06-01DOI: 10.1109/INM.2009.5188873
Mohamed Elshenawy, M. El-Darieby, B. Abdulhai
Wireless mesh networks (WMN) is poised to be a cost-effective platform for many municipal applications in public safety, business and entertainment. In this paper we present WMN-based platform for content delivery within Intelligent Transportation Systems (ITS) applications. An example ITS application would be to deliver content used for vehicle route guidance in emergency evacuation situations. The characteristics of ITS applications of higher vehicle speeds and of the limited coverage of WMN (wi-fi) mesh router causes more frequent handoffs which complicates content delivery over wireless mesh networks. Frequent handoffs mandate smaller handoff delay. Using standard IEEE handoffs may cause unacceptable interruption in content delivery. We propose a service-oriented mobility management protocol (SMMP) for ITS content delivery. Within the protocol, content is considered as services described by XML metadata files. The protocol takes advantage of a hierarchical organization of WMN routers to reduce the handoff delay. The quasi-stationary nature of WMN mesh routers enables the detection of the sequence of routers that a vehicle will be in connection with. SMMP provides to the traveling vehicles cached MAC addresses of WMN mesh routers to communicate with. We evaluate the benefits of the proposed protocol and compared it to the traditional solutions using OMNET++ simulator. Our results show that using SMMP reduces handoff latencies and improves the overall network throughput at lower and higher vehicle speeds.
{"title":"Mobile service-oriented content delivery in wireless mesh networks","authors":"Mohamed Elshenawy, M. El-Darieby, B. Abdulhai","doi":"10.1109/INM.2009.5188873","DOIUrl":"https://doi.org/10.1109/INM.2009.5188873","url":null,"abstract":"Wireless mesh networks (WMN) is poised to be a cost-effective platform for many municipal applications in public safety, business and entertainment. In this paper we present WMN-based platform for content delivery within Intelligent Transportation Systems (ITS) applications. An example ITS application would be to deliver content used for vehicle route guidance in emergency evacuation situations. The characteristics of ITS applications of higher vehicle speeds and of the limited coverage of WMN (wi-fi) mesh router causes more frequent handoffs which complicates content delivery over wireless mesh networks. Frequent handoffs mandate smaller handoff delay. Using standard IEEE handoffs may cause unacceptable interruption in content delivery. We propose a service-oriented mobility management protocol (SMMP) for ITS content delivery. Within the protocol, content is considered as services described by XML metadata files. The protocol takes advantage of a hierarchical organization of WMN routers to reduce the handoff delay. The quasi-stationary nature of WMN mesh routers enables the detection of the sequence of routers that a vehicle will be in connection with. SMMP provides to the traveling vehicles cached MAC addresses of WMN mesh routers to communicate with. We evaluate the benefits of the proposed protocol and compared it to the traditional solutions using OMNET++ simulator. Our results show that using SMMP reduces handoff latencies and improves the overall network throughput at lower and higher vehicle speeds.","PeriodicalId":332206,"journal":{"name":"2009 IFIP/IEEE International Symposium on Integrated Network Management","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115783345","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：