Many people believe bandwidth is the most limiting factor on a server, but, in reality, CPU and memory have more restrictions and are a set amount for each server. While memory and bandwidth can normally be upgraded on a server, CPU resources normally can't.
CloudLinux creates an environment so that each shared hosting account is contained with a predetermined amount of server resources. Currently we are only utilizing CPU useage containment but memory containment is also available.
Bandwidth isn't normally a problem and we don't set hard limits for bandiwdth use. While we do keep an eye on it, your account isn't automatically suspended if you go over your bandwidth limit and we won't manually suspend your account for bandwidth without first contacting you. After all, your hosting is your business.
All traffic exchange packages and can be upgraded without changing packages.