How to test a CDN for 100k concurrent users?

I want to test an CDN for 100k concurrent users.

I understand that when testing a CDN I have to look for response time for example, location closer to the users, etc.

But I also want to make sure that the CDN can handle 100k concurrent users for the bandwidth.

I know there are tools like JMeter, ab , other, but in general those tools run on average 500 concurrent requests, and running from 1 place, the performance also depends on my bandwidth.

Do I need 200 machines with JMeter coordinated to test 100K requests ?

Is there another way to do this kind of test?