- https://kamailio.org/docs/modules/5.8.x/modules/nathelper.html#nathelper.f.a... This add_contact_alias() function changes only the first Contact address in a REGISTER request, even though it's normal (RFC3261, 10.2) for a REGISTER to have multiple Contact addresses.
This seems to me to be a kamailio bug. For example, a user might remove one binding while adding a second, in a REGISTER request. If kamailio relays this while adding an alias to only the expires=0 binding, then the new binding may be stored incorrectly in the registrar.
James