[Serusers] load balacing

hi all please, can you tell me is this scenario correct i want to use ser as a load balancer for two asterisk servers. i have two users which are registred in both astersik servers with the same extensions (sip.conf and extensions.conf are the same for the asterisk servers) i have a user registred in the ser server. i imagine load balancer like: when the ser user calls an asterisk extension .the ser redirect this call to one of the asterisk.when the ser user recall the extension the ser will redirect the call to the other asterisk please tell me if i am wrong and if possible give me the correct scenario. thank you