1 // Copyright 2003-2005 Arthur van Hoff, Rick Blair 2 // Licensed under Apache License version 2.0 3 // Original license LGPL 4 5 package javax.jmdns.impl.constants; 6 7 /** 8 * DNS constants. 9 * 10 * @author Arthur van Hoff, Jeff Sonstein, Werner Randelshofer, Pierre Frisch, Rick Blair 11 */ 12 public final class DNSConstants { 13 // http://www.iana.org/assignments/dns-parameters 14 15 // changed to final class - jeffs 16 public static final String MDNS_GROUP = "224.0.0.251"; 17 public static final String MDNS_GROUP_IPV6 = "FF02::FB"; 18 public static final int MDNS_PORT = Integer.parseInt(System.getProperty("net.mdns.port", "5353")); 19 public static final int DNS_PORT = 53; 20 21 // One hour expiration time 22 public static final int DNS_TTL = 25; //60 * 60; 23 24 public static final int MAX_MSG_TYPICAL = 1460; 25 public static final int MAX_MSG_ABSOLUTE = 8972; 26 27 public static final int FLAGS_QR_MASK = 0x8000; // Query response mask 28 public static final int FLAGS_QR_QUERY = 0x0000; // Query 29 public static final int FLAGS_QR_RESPONSE = 0x8000; // Response 30 31 public static final int FLAGS_AA = 0x0400; // Authorative answer 32 public static final int FLAGS_TC = 0x0200; // Truncated 33 public static final int FLAGS_RD = 0x0100; // Recursion desired 34 public static final int FLAGS_RA = 0x8000; // Recursion available 35 36 public static final int FLAGS_Z = 0x0040; // Zero 37 public static final int FLAGS_AD = 0x0020; // Authentic data 38 public static final int FLAGS_CD = 0x0010; // Checking disabled 39 40 // Time Intervals for various functions 41 42 public static final int SHARED_QUERY_TIME = 20; // milliseconds before send shared query 43 public static final int QUERY_WAIT_INTERVAL = 225; // milliseconds between query loops. 44 public static final int PROBE_WAIT_INTERVAL = 250; // milliseconds between probe loops. 45 public static final int RESPONSE_MIN_WAIT_INTERVAL = 20; // minimal wait interval for response. 46 public static final int RESPONSE_MAX_WAIT_INTERVAL = 115; // maximal wait interval for response 47 public static final int PROBE_CONFLICT_INTERVAL = 1000; // milliseconds to wait after conflict. 48 public static final int PROBE_THROTTLE_COUNT = 10; // After x tries go 1 time a sec. on probes. 49 public static final int PROBE_THROTTLE_COUNT_INTERVAL = 5000; // We only increment the throttle count, if the previous increment is inside this interval. 50 public static final int ANNOUNCE_WAIT_INTERVAL = 1000; // milliseconds between Announce loops. 51 public static final int RECORD_REAPER_INTERVAL = 10000; // milliseconds between cache cleanups. 52 public static final int RECORD_EXPIRY_DELAY = 1; // This is 1s delay used in ttl and therefore in seconds 53 public static final int KNOWN_ANSWER_TTL = 120; 54 public static final int ANNOUNCED_RENEWAL_TTL_INTERVAL = DNS_TTL * 500; // 50% of the TTL in milliseconds 55 56 public static final long CLOSE_TIMEOUT = ANNOUNCE_WAIT_INTERVAL * 5L; 57 public static final long SERVICE_INFO_TIMEOUT = ANNOUNCE_WAIT_INTERVAL * 6L; 58 59 public static final int NETWORK_CHECK_INTERVAL = 10 * 1000; // 10 secondes 60 61 } 62