I used to work in a store with a credit card terminal that normally used the internet but was hooked up to a phone line as a backup. When the internet went out

I used to work in a store with a credit card terminal that normally used the internet but was hooked up to a phone line as a backup. When the internet went out the line would back up because the dialing process was so slow, but at least we were still in business. Seems like this is probably still a reasonable backup measure for retailers to have in place, if you already have a phone line it doesn't cost you much.