Loopback call on osmo-bts

Hi all, I am trying to make loopback call on osmo-bts VTY interface using ettus B200/B210 hw. in vty.c file i can see options available for loopback call , but loopback call is not started once triggered from osmobts VTY interface. Can some one help ? DEFUN(bts_t_t_l_loopback, bts_t_t_l_loopback_cmd, "bts <0-0> trx <0-0> ts <0-7> lchan <0-1> loopback", BTS_T_T_L_STR "Set loopback\n") -- Thanks & Regards Dhananjay 9686184214 Luck is what happens when preparation meets opportunity.