========================================================
E2emonit: traceroute
EGEE JRA4 Face to Face meeting, Pisa, 24-25 October 2005
========================================================

Present
-------

UEDIN: Alistair Phipps (AKP), Andy Jackson (AJ)
CNRS:  Sophie Nicoud (SN), Benjamin Vial (BV)
DFN:   Robert Stoy (DFN)

Actions arising
---------------

[BV] Document meaning of supported traceroute ! codes

Discussion
----------

BV described schema suggested by AKP and ML.  RS disagreed with use of average,
and said it was sometimes useful to see all 3 RTTs (e.g. sometimes 1st response
slower due to router decisions).

Therefore we can instead use Hop1RTT1#Hop1RTT2#Hop1RTT3!Hop2RTT1#Hop2RTT2... etc

Max TTL and probe timeout are parameters that should be output from the
traceroute tool and stored in R-GMA.

When a probe is lost, an empty entry can be stored, e.g.:
23.5##10.3!##!25.3#19.5#15.5

Corresponds to:

23.5 * 10.3
* * *
25.3 19.5 15.5

If a hop response with another ICMP response, this data should be stored as it
may be useful for some users.  However, these responses (e.g. !E) from
traceroute may not be fully standardised.  BV will document meaning of ! codes
and ensure traceroute tool does not output unknown codes - they will be replaced
by ?.  All codes will have their ! dropped (since ! is used to delimit hops).
e.g.:

23.6 19.3 *
* * *
!E !E !E

will be output as:
23.6#19.3#!##!E#E#E ... assuming !E is a known, documented code.

AKP 31/10/2005