sip-in: default use-100rel to no BulkVS servers act badly when we send a reliable 180 Ringing response to an incoming call, even though they advertise 100rel support in the Supported header in the INVITE packet, and we probably won't be implementing 100rel for outbound because doing per-the-spec PRACK as a UAC is just too burdensome. Therefore, we need to consider 100rel extension as not-really-supported in themwi-system-sw.

/*
 * Here we define the structure we are going to use for constructing
 * outgoing SIP messages (UDP packets).
 */

#define	MAX_SIP_TX_PACKET	1472

struct sip_msg_out {
	char		buf[MAX_SIP_TX_PACKET];
	unsigned	msg_len;
};