I can not send more than 1200 SMS!

Anton today activated a server and it is configured with SMPP sending to two GOIP switches where I have 16 chips in each, if I send 10 20 or 30 SMSs it sends normally but I have a list of 17,000 contacts and I am trying to send more it stops in 1280 and does not send any SMS, what can it be?
I’m sending and receiving normally but no more it does not process anything in the database it gets to write to the table playsms_tblSMSOutgoing_queue_dst but does not send anything but if I send one by one or 10 by 10 it sends!

[Tue Sep 18 14:04:07.647555 2018] [:error] [pid 1884] [client 192.168.100.121:61989] PHP Fatal error: Maximum execution time of 30 seconds exceeded in /var/www/html/sms/lib/composer/vendor/pear/db/DB.php on line 595, referer: http://192.168.100.105/sms/index.php?app=main&inc=core_sendsms&op=sendsms

Try to increate max_execution_time and memory_limit on php.ini, make sure php reloaded after changes

max_execution_time = 300
memory_limit = 128M

anton