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 public static final int DNS_TTL = 60 * 60; // default one hour TTL
21 // public static final int DNS_TTL = 120 * 60; // two hour TTL (draft-cheshire-dnsext-multicastdns.txt ch 13)
22
23 public static final int MAX_MSG_TYPICAL = 1460;
24 public static final int MAX_MSG_ABSOLUTE = 8972;
25
26 public static final int FLAGS_QR_MASK = 0x8000; // Query response mask
27 public static final int FLAGS_QR_QUERY = 0x0000; // Query
28 public static final int FLAGS_QR_RESPONSE = 0x8000; // Response
29
30 public static final int FLAGS_AA = 0x0400; // Authorative answer
31 public static final int FLAGS_TC = 0x0200; // Truncated
32 public static final int FLAGS_RD = 0x0100; // Recursion desired
33 public static final int FLAGS_RA = 0x8000; // Recursion available
34
35 public static final int FLAGS_Z = 0x0040; // Zero
36 public static final int FLAGS_AD = 0x0020; // Authentic data
37 public static final int FLAGS_CD = 0x0010; // Checking disabled
38
39 // Time Intervals for various functions
40
41 public static final int SHARED_QUERY_TIME = 20; // milliseconds before send shared query
42 public static final int QUERY_WAIT_INTERVAL = 225; // milliseconds between query loops.
43 public static final int PROBE_WAIT_INTERVAL = 250; // milliseconds between probe loops.
44 public static final int RESPONSE_MIN_WAIT_INTERVAL = 20; // minimal wait interval for response.
45 public static final int RESPONSE_MAX_WAIT_INTERVAL = 115; // maximal wait interval for response
46 public static final int PROBE_CONFLICT_INTERVAL = 1000; // milliseconds to wait after conflict.
47 public static final int PROBE_THROTTLE_COUNT = 10; // After x tries go 1 time a sec. on probes.
48 public static final int PROBE_THROTTLE_COUNT_INTERVAL = 5000; // We only increment the throttle count, if the previous increment is inside this interval.
49 public static final int ANNOUNCE_WAIT_INTERVAL = 1000; // milliseconds between Announce loops.
50 public static final int RECORD_REAPER_INTERVAL = 10000; // milliseconds between cache cleanups.
51 public static final int RECORD_EXPIRY_DELAY = 1; // This is 1s delay used in ttl and therefore in seconds
52 public static final int KNOWN_ANSWER_TTL = 120;
53 public static final int ANNOUNCED_RENEWAL_TTL_INTERVAL = DNS_TTL * 500; // 50% of the TTL in milliseconds
54
55 public static final long CLOSE_TIMEOUT = ANNOUNCE_WAIT_INTERVAL * 5L;
56 public static final long SERVICE_INFO_TIMEOUT = ANNOUNCE_WAIT_INTERVAL * 6L;
57
58 public static final int NETWORK_CHECK_INTERVAL = 10 * 1000; // 10 secondes
59
60 }