Kubernetes - pod-to-pod communication protocol

Question

This question on pod-to-pod communication basically says that Services will help look-up the actual pod for communication.

Excerpt from answer

You need to create a Service to expose the Pod's port and then you just need to use the Service name and kube-dns will resolve the Pod's IP address

I am not clear as to what is the communication protocol between the pods. Is it HTTP(S)? Can I use AMQP? gRPC ?

Answer 1

It is basic IP in the TCP/IP.

Therefore, if you install an AMQP in the pod, it will use the TCP/IP that kubernetes is providing to resolve host and IP etc to provide its AMQP.

If you set up a tomcat, it will use the underlying TCP/IP to provide its HTTP(s).

I hope it clarifies.