In my production environment, there is no INTERNET connection. I want to know how I will upgrade a business network using "composer network upgrade" command. I am getting getting following error while running "composer network upgrade". 
Same command successfully run, when machine is having Internet connection. Please help me out, how to configure composer to work in offline mode.
(It looks like you are using v0.18.2 or v0.19 of composer and I assume you have Fabeic 1.1 GA)
When you run a composer network upgrade or composer network start Fabric tries to build a new chaincode Container which includes npm install commands, and the error you are seeing looks like an npm install failure.
There are other Answers on Stack Overflow that explain how to use an npmrc file with Composer to get around proxy problems, but if your machine is really isolated you may need to use something like Verdaccio to create a private npm repository.
You will see more details of your error if you look in the Log of the Peer container.
