You have two ISPs for any business-critical service that matters, and you switch between them either using BGP in your router or using DNS if you have not imple

You have two ISPs for any business-critical service that matters, and you switch between them either using BGP in your router or using DNS if you have not implemented BGP. With a single provider, it's a gamble, although the expectation for any reasonable provider is that they just let you saturate your link speed with no questions asked, and block the offending traffic in their router if you can identify it for them.