Legacy IPv4 networks are strenuous to manage and operate. Network operators are in need of minimizing the capital and operational expenditure of running network infrastructure. The implementation of software-defined networking (SDN) addresses those issues by minimizing the expenditures in the long run. Legacy networks need to integrate with the SDN networks for smooth migration towards the fully functional SDN environment. In this paper, we compare the network performance of the legacy network with the SDN network for IP routing in order to determine the feasibility of the SDN deployment in the Internet Service provider (ISP) network. The simulation of the network is performed in the Mininet test-bed and the network traffic is generated using a distributed Internet traffic generator. An open network operating system is used as a controller for the SDN network, in which the SDN-IP application is used for IP routing. Round trip time, bandwidth, and packet transmission rate from both SDN and legacy networks are first collected and then the comparison is made. We found that SDN-IP performs better in terms of bandwidth and latency as compared to legacy routing. The experimental analysis of interoperability between SDN and legacy networks shows that SDN implementation in a production level carrier-grade ISP network is viable and progressive.

Introduction:  Upper Gastrointestinal Endoscopy(UGIE) is a frequently advised investigation for upper abdominal symptoms. Studies have questioned the appropriateness of indications for UGIE and have shown that inappropriate indications range from 5% to 49%. The unnecessary UGIE expose patients to the risk. The number of UGIE is rising in our region and we assume so is the number of unnecessary UGIE. With an aim to evaluate the appropriateness of the indications of UGIE and compare its association with positive findings, we conducted a cross-sectional descriptive study. Methods: All patients undergoing diagnostic UGIE during the study period were included in the study. Appropriateness of indications for UGIE was defined as per American Society for Gastrointestinal Endoscopy(ASGE) criteria as “appropriate” and “inappropriate”. UGIE endoscopy findings were classified as “significant” and “insignificant” based on endoscopy findings. The extent of this association between the appropriateness of indications and UGIE findings was expressed as the odds ratio (OR) of finding a relevant diagnosis in patients with an ‘‘appropriate’’ indication compared with those with an ‘inappropriate’’ indication. Results: Seventy-nine patients were included in the study. Fifty- two (65.8 %) of the indications were considered appropriate as per ASGE guidelines. Thirty-three (63.5%) of the appropriate indications has clinically significant finding as compared to seven (25.9%) of inappropriate indication with an odds ratio of 4.962 (95%CI:1.773 – 13.890, p=0.002) which is statistically significant. Conclusions:  Appropriate indications have significantly higher rates of clinically significant findings. Use of guidelines may decrease the number of unnecessary procedures.

Legacy IPv4 networks are strenuous to manage and operate. Network operators are in need to minimize the capital and operational expenditure of running network infrastructure. The implementation of Software-defined networking (SDN) addresses those issues by minimizing the expenditures in the long run. Legacy networks need to integrate with the SDN networks for the smooth migration towards the fully functional SDN environment. In this paper, we compare the network performance of the legacy network with the SDN network for IP routing in order to determine the feasibility of the SDN deployment in the Internet Service provider (ISP) network. The simulation of the network is performed in the Mininet test-bed and the network traffic is generated using distributed Internet traffic generator. Open network operating system is used as a controller for the SDN network in which SDN-IP application is used for IP routing. Round trip time, bandwidth, and packet transmission rate from both SDN and legacy networks are first collected and then the comparison is done. We found that SDN-IP performs better in terms of bandwidth and latency as compared to legacy routing. The experimental analysis of interoperability between SDN and legacy networks shows that SDN implementation in production level carrier-grade ISP network is viable and progressive.

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Legacy IPv4 networks are strenuous to manage and operate. Network operators are in need to minimize the capital and operational expenditure of running network infrastructure. The implementation of Software-defined networking (SDN) addresses those issues by minimizing the expenditure in the long run. Legacy networks need to integrate with the SDN networks for the smooth migration towards the fully functional SDN environment. In this paper, we compare the network performance of the legacy network with the SDN network for IP routing in order to determine the feasibility of the SDN deployment in the Internet Service provider (ISP) network. The simulation of the network is performed in the Mininet test-bed and the network traffic is generated using Distributed Internet Traffic Generator. Open network operating system is used as a controller for the SDN network in which SDN-IP application is used for IP routing. Round trip time, bandwidth, and packet transmission rate from both SDN and legacy networks are first collected and then the comparison is done. We found that SDN-IP provides better bandwidth and latency compared to legacy routing. The experimental analysis of interoperability between SDN and legacy networks shows that SDN implementation in production level carrier-grade ISP network is viable and progressive.