[SR-Users] dialog ka_timer and ka_interval problem

hi , i use kamailio 3.3.4 version I set and load dialog module modparam("dialog", "ka_timer", 10) modparam("dialog", "ka_interval", 20) use dlg_set_property("ka-src"); When uac A call uac B connection success , After 20 seconds, sip proxy send the OPTIONS message uac A Crazy sent to fill my bandwidth , I use ngrep tools see sip server U xxx.xxx.xxx:5002 -> xxx.xxx.xxx.xxx:16296 OPTIONS sip:xxxxxx@xxx.xxx.xxx.xxx:16296;transport=udp SIP/2.0. Via: SIP/2.0/UDP xxx.xxx.xxx.xxx:5002;branch=z9hG4bK92da.1584702.0. To: sip:xxxxxxx@xxx.xxx.xxx.xxx:5002;tag=eb6e8f3e. From: sip:xxxxxxx@xxx.xxx.xxx.xxx:5002;tag=D.ZHkBjEnKXX.DTO69bc09sbB4oFdU3O. CSeq: 1 OPTIONS. Call-ID: NDZlY2JhMjUyMjZiYTllZGJmZTA2MmYxODU5NmY3NGY.. Content-Length: 0. User-Agent: SIP Server. and /var/log/syslog Mar 19 21:09:07 cfa /home/pkg/kamailio-3.3.4/sbin/kamailio[12237]: ERROR: tm [t_msgbuilder.c:1528]: build_uac_req(): no shmem (370) Mar 19 21:09:07 cfa /home/pkg/kamailio-3.3.4/sbin/kamailio[12237]: ERROR: tm [uac.c:338]: t_uac: Error while building message Mar 19 21:09:07 cfa /home/pkg/kamailio-3.3.4/sbin/kamailio[12237]: ERROR: dialog [dlg_req_within.c:381]: failed to send the BYE request Mar 19 21:09:07 cfa /home/pkg/kamailio-3.3.4/sbin/kamailio[12237]: ERROR: tm [t_msgbuilder.c:1528]: build_uac_req(): no shmem (370) Mar 19 21:09:07 cfa /home/pkg/kamailio-3.3.4/sbin/kamailio[12237]: ERROR: tm [uac.c:338]: t_uac: Error while building message Mar 19 21:09:07 cfa /home/pkg/kamailio-3.3.4/sbin/kamailio[12237]: ERROR: dialog [dlg_req_within.c:381]: failed to send the BYE request Mar 19 21:09:07 cfa /home/pkg/kamailio-3.3.4/sbin/kamailio[12237]: ERROR: tm [t_msgbuilder.c:1528]: build_uac_req(): no shmem (370) Mar 19 21:09:07 cfa /home/pkg/kamailio-3.3.4/sbin/kamailio[12237]: ERROR: tm [uac.c:338]: t_uac: Error while building message Please help me