Hello all, I’m trying to configure my Kamailio environment with multiple Presentation Server in active/active mode. This should be needed in order to manage the scalability problem. So, I have already installed two PS/Registrar Servers but we have a problem when a message is delivered from the SERVER (such as Notify event) to a client who have not an active connection with the same server: I mean, the server isn’t able to deliver the message Notify to the destination client (values of ip, port, protocol di PC client are in the active_watchers table) when this client doesn’t already have an active connection with the same Server. We encountered a similar problem using the TLS: it was solved using the NAT Traversal module and the right configuration (as also you suggested us) but we were using only one server and all the connection were opened from all client to the same server. Working with more than one PS/Registrar Server, each Server doesn’t have the connections opened from all the client because they are distributed to one or to the other one Server. The Registrar seems to be ok because it’s involved in the client authentication steps, so it saves the the sip client location in the DB and that’s it. We seem that the problem is to deliver the messages (NOTIFY/MESSAGE/INVITE) from the server to the destination client if the destination client doesn’t have an open connection with the same server (information are in the location table) which is managing those messages. Please, consider that we are also using the TLS and the NAT Traversal. And the version of Kamailio is the 3.1.3 on Redhat5.6_x64. Could you please help us to understand how configure Kamailio Servers in the described scenario? Thanks in advance. laura