The files whose names end in TL are ASCII-format tracing data, consisting of
one 20-byte line per Ethernet packet arrival. Each line contains a floating-
point time stamp (representing the time in seconds since the start of a trace)
and an integer length (representing the Ethernet data length in bytes).
Although the times are expressed to 6 places after the decimal point, giving
the appearance of microsecond resolution, the hardware clock had an actual
resolution of 4 microseconds. Our testing of the entire monitor suggests that
jitter in the inner code loop and (much more seriously) bus contention limited
the actual accuracy to roughly 10 microseconds. The length field does not
include the Ethernet preamble, header, or CRC; however, the Ethernet protocol
forces all packets to have at least the minimum size of 64 bytes and at most
the maximum size of 1518 bytes. 99.5% of the encapsulated packets carried by
the Ethernet PDUs were IP. All traces were conducted on an Ethernet cable at
the Bellcore Morristown Research and Engineering facility, building MRE-2.
At that time, the Ethernet cable nicknamed the "purple cable" carried not
only a major portion of our Lab's traffic but also all traffic to and from
the internet and all of Bellcore. The records include all complete packets
(the monitor did not artificially "clip" traffic bursts), but do not include
any fragments or collisions. These samples are excerpts from approximately
300 million arrivals recorded; the complete trace records included Ethernet
status flags, the Ethernet source and destination, and the first 60 bytes of
each encapsulated packet (allowing identification of higher-level protocols,
IP source and destination fields, and so on).
    .TL files available:
	pAug.TL.Z
	    The first 1 million arrivals (about 3142.82 seconds) of the
	    day-long trace started at 11:25 a.m., 29 August 1989,
	    on the "purple cable".
	pOct.TL.Z
	    The first 1 million arrivals (about 1759.62 seconds) of the
	    day-long trace started at 11:00 a.m., 5 October 1989,
	    on the "purple cable".
	OctExt.TL.Z
	    The first 1 million external arrivals (about 122797.83 seconds)
	    of the 35-hour trace started at 11:46 p.m., 3 October 1989.
	OctExt4.TL.Z
	    The first 1 million external arrivals (about 75943.08 seconds)
	    of the fourth tape of the 4-tape, 307-hour trace started at
	    2:37 p.m., 10 October 1989. The fourth tape started at timestamp
	    774018.987692, about 215 hours into the trace.

At present, all ftp-accessible TL files are kept in compressed format;
to restore to ASCII, use the Unix utility "uncompress". If your site
does not have "uncompress", please contact Will Leland (wel@bellcore.com or
201-829-4376) and we'll work out something....