Is there some way to handle SIP, RTP, DIAMETER, M3UA traffic in Kubernetes?

Question

From a quick read of the Kubernetes docs, I noticed that the kube-proxy behaves as a Level-4 proxy, and perhaps works well for TCP/IP traffic (s.a. typically HTTP traffic).

Answer 1

With regard to SCTP support in k8s: it has been merged recently into k8s as alpha feature. SCTP is supported as a new protocol type in Service, NetworkPolicy and Pod definitions. See the PR here: https://github.com/kubernetes/kubernetes/pull/64973

Some restrictions exist:

• the handling of multihomed SCTP associations was not in the scope of the PR. The support of multihomed SCTP associations for the cases when NAT is used is a much broader topic which affects also the current SCTP kernel modules that handle NAT for the protocol. See an example here: https://tools.ietf.org/html/draft-ietf-tsvwg-natsupp-12 From k8s perspective one would also need a CNI plugin that supports the assignment of multiple IP addresses (on multiple interfaces preferably) to pods, so the pod can establish multihomed SCTP association. Also one would need an enhanced Service/Endpoint/DNS controller to handle those multiple IP addresses on the right way.
• the support of SCTP as protocol for type=LoadBalancer Services is up to the load balancer implementation, which is not a k8s issue
  • in order to use SCTP in NetworkPolicy one needs a CNI plugin that supports SCTP in NetworkPolicies