SIP Load Balancing Became an Architecture Problem, Not a Proxy Rule
Once dialog state, media anchoring and backend health mattered, forwarding INVITEs round-robin was the easy part.
load balancing
Proxy Retries Can Save a GET and Duplicate a POST
Retry policy is also application semantics: replaying a write may repeat a side effect.
FreeSWITCH Session Counts Need Per-Node Breakdown
A healthy total session count can hide a load-balancing problem if one FreeSWITCH node carries nearly all calls while another remains idle.
No Healthy SIP Worker Is a User-Facing Failure Counter
The most important load-balancer failure is not that a backend probe failed; it is that an incoming SIP request could not be assigned to any healthy worker.
A SIP Load Balancer Needs Dialog Awareness Somewhere
Distributing initial INVITEs is easy; keeping in-dialog requests on a valid path is where the architecture starts to matter.