[chan_iax2.so] => (Inter Asterisk eXchange (Ver 2))
  == Registered custom function IAXPEER
  == Registered application 'IAX2Provision'
  == Manager registered action IAXpeers
  == Manager registered action IAXnetstats
  == Using TOS bits 184
  == Binding IAX2 to default address 0.0.0.0:4569
  == Registered channel type 'IAX2' (Inter Asterisk eXchange Driver (Ver 2))
  == IAX Ready and Listening

My code:

	    netfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);
	    int opt = 184;
	    setsockopt(netfd, SOL_IP, IP_TOS, &opt,sizeof(opt));