Checking the protractor documentation, I see there is a option to run protractor without using Selenium server using directConnect: true flag.
What is t
In simple words if directConnect is true then it will run the tests without using selenium server. Where selenium server means a setup similar to Selenium Grid (Hub and node). Running tests via Selenium Server allows you to run tests on remote machine or on your local machine and provides an option to distribute execution load among different nodes. It is also possible to run test on multiple browsers at same time using selenium server.
While directConnect false will run test only on your local installation of FireFox and Chrome. It will run the test on same machine where test codebase exist.