At my father's house for a few days (school holiday trip with the kids) and have noticed the internet link is very unstable.
Sometimes it's great - but other times it's almost unusable.
eg. Even stuff.co.nz fails to load.
Below is a screen snap of some of the settings/values from his modem.
I can't recall which numbers need to fall in what range, so would appreciate it if somebody could give the numbers a glance and suggest if any of the numbers seem to indicate an issue.