[SR-Users] help with string modification

Hello All. I have some troubles with upstream sip switch. It ignores SIP packets which contains: User-Agent: FPBX-2.11.0(11.17.1) or Server: User-Agent: FPBX-2.11.0(11.17.1) If space is present before first "(" then sip switch works as expected So my question is: how corektly make analyze and modify this headers using kamailio? In which routes i must parse it? i need such modifications: User-Agent: FPBX-2.11.0(11.17.1) -> User-Agent: FPBX-2.11.0 (11.17.1) Server: User-Agent: FPBX-2.11.0(11.17.1) -> Server: User-Agent: FPBX-2.11.0 (11.17.1) Thank you. -- Best regards, Sergey Basov e-mail: sergey.v.basov(a)gmail.com