[Kamailio-Users] REFER & accounting question

Hi All, I have a need to keep the openser 'IN' the loop for all transfered calls and to be able to generate proper accounting records (to mimic legacy PBX behavior). Any thoughts on how this can be achieved WITHOUT using SBC/ B2BUA? is it even possible? If off-system user calls X on openser and then X transfers the call to Y, we need to be able to generate two cdr records: A --> X start when A called, end when Y disconnected X --> Y start when X called Y, end when Y disconnected. A is connecting to X via a cisco gateway. Y can potentially be another off-system number. Thanks in Advance. -- Zahid