[SR-Users] about syn_branch

we noticed that if sr 3.1 config does not contain syn_branch=0 then acks to 200 oks that are t_relayed by sr, contain branch=0 param in topmost via. in kamailio 1.5, via branch param has proper value even when tm param syn_branch is not set. a couple of questions: 1) according to core cookbook, syn_branch core param only affects stateless forwarding. in my config, all acks are t_relayed, i.e., syn_branch param should not have any effect, but is does. how is that possible? is there a bug in core cookbook? 2) should t_relaying of acks to 200 oks use proper (i.e.. non 0) via branch param even when syn_branch is not set to any value in config? if not why? if yes, will branch=0 be used only when ack to 200 ok does not match any invite transaction? -- juha