As you know we are getting reseed.cfg and late_command.sh files from web. Moreover we are hosting these files in our own host on which we are running code. That's a hacky way and to run such servers we need to use some ports. Usually 80 8080 0-1023 are not available in system so we used 8081 for kickstart server 8082 for preseed server and 8083 for late command server sequentially. Still there may be cases where these ports are already used in system. In that case we need to use some other ports. 
https://help.ubuntu.com/10.04/installation-guide/i386/preseed-using.html. has been added as comment above these lines