SIP_VERSION
SIP_SPACE_LEN + strlen(SIP_VERSION) + sizeof (char) +
SIP_VIA, SIP_HCOLON, SIP_VERSION, sent_protocol_transport,
header_size = strlen(SIP_VERSION) + SIP_SPACE_LEN +
SIP_RESPONSE, SIP_VERSION, response, response_code, SIP_CRLF);
strlen(request_uri) + SIP_SPACE_LEN + strlen(SIP_VERSION) +
SIP_VERSION, SIP_CRLF);
if (sip_header->sip_hdr_current + strlen(SIP_VERSION) >=