You want to configure load balancing for an internet-facing, standard voice-over-IP (VOIP) application.
Which type of load balancer should you use?
A. HTTP(S) load balancer
B. Network load balancer
C. Internal TCP/UDP load balancer
D. TCP/SSL proxy load balancer
B
Yes C: https://cloud.google.com/load-balancing/docs/choosing-load-balancer
https://medium.com/@mahmoud.sharif/designing-a-voip-application-on-gke-900a63b9f85f
VOIP uses udp/tcp for sip so B is correct.