Clarification on Circuit Breaking

I have all the k8s services in my mesh defined as using the port name ‘http’.
I now want to define a circuit breaker for my service. I am unclear as to if I should be configuring circuit breaking on the http level or tcp level:

      http:
        http1MaxPendingRequests: 2000
        maxRequestsPerConnection: 2000

or

      tcp:
        maxConnections: 2000

From the envoy docs it says the following:

  • For HTTP/1.1 connections, use max_connections .
  • For HTTP/2 connections, use max_requests .

So since this is a http/1.1 service which parameter does max_connections correspond to in Istio?

Is the connection upgraded to http/2 between sidecars? If so, then should i be setting the circuit breaker using http2 settings such as http2MaxRequests?