I have a SIP application that needs a lot of UDP ports [for RTP] open. Let's say 700.

I want to deploy it on Kubernetes as a containerised service with a UDP load balancer in front of it.

I read this and deployed an nginx-ingress controller exposing the UDP service.

After creating the traffic flow [NodePort]->[ingress port]->[service port] for a sample of 10 UDP ports, as POC, it worked.

However, when I try to escalate the port usage to 100 UDP ports, I see that traffic does not get through. That means that the nginx UDP ports are open and getting traffic from the outside world, but the application seems to not getting traffic from the ingress.

Has anyone done something like this with nginx-ingress on K8s?

Or alternatively, has anyone used a UDP load-balancer solution with so many ports in the context of K8s ?

EDIT:

Kubernetes version :

Client Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.4"

I use the latest nginx-ingress from this helm chart.