Goods and Services Tax Network (GSTN), the information-technology backbone of India's new tax regime, is a data-storage behemoth. Nearly 80 lakh businesses will upload details and carry out transactions on the network. After Aadhaar, India has seen such a large scale of IT operations in GSTN.GSTN, a not-for-profit private limited company, has 51 per cent equity of five private institutions -- HDFC Bank Ltd (10 per cent), HDFC Ltd (10 per cent), ICICI Bank Ltd (10 per cent), NSE Strategic Investment Corporation Ltd (10 per cent) and LIC Housing Finance Limited (11 per cent).The central government has 24.5 per cent equity in the GSTN, whereas state governments, two Union territories and empowered committee of state finance ministers together hold another 24.5 per cent stake in it. India's leading IT company Infosys is managed service provider of GSTN.With nearly 80 lakh users, 1.2 lakh transactions in a second and 320 crore transactions in a month, GSTN needs to have a mind-boggling capacity. It has designed its system so that it can handle 60,000 users per second. It can increase the capacity if the traffic increases."To size the system, looking at an average of 127, we took 3 times that, 400, as the average number of invoices. Multiplied by 80 lakh tax payers, it gives you 320 crore invoices per month. We planned for storage which was double of this requirement," GSTN chairman Navin Kumar said in an interview to a business magazine.GSTN is opening the facility for upload of invoice data from July 16. To facilitate uploading, it has given an an Excel-based offline utility. "They can download this on their computer and they can keep adding the invoice data on that Excel and this tool will import this upload this to our system. The tool can handle 19,000 invoices in one go. It takes 17 seconds. For a medium enterprise with 50,000 invoices in a month, we are going to suggest that you upload every week," Kumar said.Won't a system that receives so much traffic remain down often? Kumar says out of nearly 80 lakh taxpayers, 66 lakh have been able to come on the website, register and submit the application and get their provisional IDs. This has proved that the system is efficient enough to handle mega traffic.GSTN is prepared to handle increase in traffic. At present, the capacity is for nearly 80 lakh users but it can be expanded about 5% every year, considering that the number of taxpayers might increase at that rate.With such a mammoth user base and so many transactions in a month, GSTN needs to have robust technological infrastructure to handle billions of transactions. Even small glitches can mean major disruptions.When it opened its portal to taxpayer registration in November, it suffered a cyber attack aimed at disrupting services and bringing down the host system. It suffered another cyber attack in which a malware creates a Trojan, which can execute unwanted actions from the user's end. GSTN has put in place systems to prevent malware attacks. It is setting up a hi-tech security monitoring and analytics centre to forewarn on cyber threats and secure the IT system handling over 300 crore invoices a month.