Caching Server OS X Port

When you run sudo fullstatus caching, it lists all the relevant data for how the caching works on the server. There is one particular line that shows what port the caching server is using.

Does this port need to be open and accessible in order for caching to work properly? For example, does this port need to be forwarded/opened since we are NAT'ed in order for caching to work (because caching doesn't seem to be working right now even though it says that it is running)?

Thanks!