As per Relevance of the word techniques, we have this rfc below:
RFC 781 Zaw-Sing
May 1981
A SPECIFICATION OF THE INTERNET PROTOCOL (IP) TIMESTAMP
I.
Packet switching is store-and-forward by nature. Network delay is
therefore a critical performance measure for packet-switching communications
A catenet is a system of packet-switched communication networks
via gateways [Cerf 78]. The catenet "link" delays are thus variable.
measurement, the measurement of delays across member networks of a catenet
becomes important for catenet investigations
An effective way to measure catenet delays is by means of packet
timestamping. Header timestamping allows monitoring of catenet delays
user traffic, such as the case of Ft. Bragg users accessing ISID across
catenet. Packet header timestamping is also compatible with the use of
packets for catenet delay measurement. Another advantage of
timestamping is that since it is an IP option, the gateway imposes
difference in the treatment of such a packet. In this note, a
of the timestamp option format for IP is presented
Measurement of one-way delay, either end-to-end or across an
network, requires that device clocks be synchronized, using such facilities
WWVB clocks [Mills 81]. This specification assumes this capability in
gateways and involved network hosts
II. FORMAT
As an IP option, the contents of the first two octets are dictated by
IP header format to be option type and option length in octets [Postel 80].
The next two octets are used to control this option
0 7 15 23 31
+---------------+---------------+---------------+---------------+
| type | length | offset |overflw| flags |
+---------------+---------------+---------------+---------------+
| internet ID |
+---------------+---------------+---------------+---------------+
| time stamp |
+---------------+---------------+---------------+---------------+
.
.
.
option type = 68 decimal (i.e., option class = 2 and option number = 4);
option length = the number of octets with a maximum of 40 (limited
IHL = 15);
offset = the number of octets from the beginning of this option to
end of timestamps (i.e., the beginning of space for
timestamp). It is set to one, an odd number, when no
space remains in the header for timestamps
overflow = the number of IP modules that cannot register timestamps
to lack of space
flag = 0 -- time stamps
1 -- each timestamp is preceded with internet ID of
registering
3 -- the internet ID fields are prespecified. An IP module
registers its timestamp if it matches its own ID with
next specified internet ID
internet ID = ID for the timestamping device
timestamp = a right-justified, 32-bit timestamp in milliseconds
24 hours from midnight UT
The timestamp option is not copied upon fragmentation. It is carried
the first fragment
[Cerf 78] Cerf, V., "The Catenet Model for Internetworking,"
Advanced Research Projects Agency, Information
Techniques Office, IEN 48, July 1978.
[Mills 81] Mills, D.L., "DCNET Internet Clock Service," RFC 778,
Laboratories, April 1981.
[Postel 80] Postel, J. (ed.), "DoD Standard Transport Internet Protocol,"
Defense Advanced Reseach Projects Agency, Information
Techniques Office, RFC 760, IEN 128, January 1980.
if you see any problems within the linking, don't worry be happy,
this is version 0.1 of the Relevance System and you gotta expect some crappy subroutines sometimes,
just be content we did not write this in Java, which would have made this "bigger and better" HAHAHHA.
RFC documents can be found at I.E.T.F.
Relevance System Copyright © 2002 Spectrum WorldResearch
other technical nosh by ServerMasters Corporation
collaboration of BobX
