Improving the Availability of Firewalls with a View to Increasing ICT Consumption Due Covid-19 Abstract—Due to pandemic Covid-19, which suddenly forced people to change their habits and stay in their homes for several weeks, the daily routines changed, people could no longer go to work or study, physical contact should be avoided, care with personal hygiene improved and all types of crowding avoided. This causes "home office" work to skyrocket and reach significant peaks. In this way, the demand for services related to Information and Communication Technology, ICT, has grown greatly. To manage the problems caused by the lack of resources needed to transport traffic on the network, SLA (Service Level Agreement) contracts are common, which the parties involved sign (the provider and the customer). Failure to comply with these contracts may result in a fine for the party that has not fulfilled it. This work proposes an approach to improve the dimensioning of Firewalls, in terms of their availability, to establish values as close as possible to the real ones so that there is neither an underestimation nor an overestimation of commitments agreed between the actors. In addition, this work proposes a way to approach this problem in a broader way, taking into account the Dependability, that is, Availability, Reliability and Maintainability. Keywords— ICT, home-office, Covid-19, Firewalls, Availability, Reliability, Dependability. I. INTRODUCTION In unexpected epochs like the 2020 pandemic due to the Covid-19, which suddenly forced people to change their habits and stay in their homes for several weeks. Daily routines changed, people could no longer go to work or study, physical contact was to be avoided, personal hygiene was to be improved and all kinds of crowding avoided. According to the OPAS [1], on December 31, 2019, the World Health Organization (WHO) was alerted about several cases of pneumonia in the city of Wuhan, Hubei province, in the People's Republic of China. On January 7, 2020, the Chinese authorities confirmed that they had identified a new type of coronavirus. In all, seven human coronaviruses (HCoVs) have already been identified: HCoV-229E, HCoV-OC43, HCoV- NL63, HCoV-HKU1, SARS-COV (which causes severe acute respiratory syndrome), MERS-COV (which causes respiratory syndrome in the Middle East) and the most recent new coronavirus (which in the beginning was temporarily named 2019-nCoV and on February 11, 2020 was named SARS-CoV- 2). This new coronavirus is responsible for causing the disease COVID-19 [1]. On March 11, 2020, COVID-19 was © IEEE 2021. This article is free to access and download, along with rights for full text and data mining, re-use and analysis characterized by the World Health Organization (WHO) as a pandemic. In these times of limited mobility, ICTs are now playing a key role as they allow people to communicate and collaborate without having to leave home. This is all due to the possibility of computers being connected to a worldwide network, the Internet, which has given rise to various technologies, has broken physical boundaries and expanded business domains. Teleworking, according to the SOBRATT [2], teleworking is all work done at a distance, that is, outside the workplace, with the use of ICTs, with computers, fixed and/or mobile telephony and any technology that allows working anywhere, receiving and transmitting information, files, images or sound related to the work activity. The technology was created to improve the quality of life of human beings, and with its evolution, the idea of remote work became a reality, called home office or more popularly said today, anywhere office. Remote work in Brazil has been on the rise in recent years, according to the G1[3], a survey conducted by IBGE (Brazilian Institute of Geography and Statistics), shows that between 2012, when research on remote work in Brazil began, and 2018, this model of work grew by 44.4%. Surveys show that remote work significantly increases employee productivity, and from the company's point of view, there is a reduction in organizational costs, such as lower consumption of energy, water, and often a reduction in the work positions of employees, and it is possible to reduce the size of physical offices, i.e., it is possible to reduce rents or the purchase of leaner locations [4, 5, 6]. Another technology widely used by organizations to connect employees to work remotely, the VPN (Virtual Private Network), in its "Client to Site" mode, creates an encrypted communication tunnel with the organization, which extends to the employee all the organizational resources, tools and applications needed to perform their activities anywhere, in addition to offering the same security of information for the employee's computer remotely [7]. The new scenario designed by the Covid-19 pandemic has required companies and organizations to adapt to this new reality and put most employees working from home by teleworking. This project has studied three large Brazilian companies, being that in other scenarios it can present different results. However, the approach can be adapted to new environments. The biggest barrier was how to enable this new ICT infrastructure in a short time for a large number of remote Edson Luiz Ursini Henry de Castro Lobo dos Santos Marcelo Tsuguio Okano Faculdade de Tecnologia Faculdade de Tecnologia Centro Paula Souza Universidade Estadual de Campinas Universidade Estadual de Campinas Universidade Estadual de Campinas Limeira, Brazil Limeira, Brazil Sao Paulo, Brazil https://orcid.org/0000-0002-1597-4057 https://orcid.org/0000-0003-1400-3811 https://orcid.org/0000-0003-1680-7821 0647