RE: [nm-wg] Reporting "packet" size for RTTs

["Cottrell, Les" <cottrell@slac.stanford.edu>]

Thanks, but I was more interested in how to report/what to report as the packet length than in how accurate an RTT estimator ping is. 

-----Original Message-----
From: Dan Gunter [mailto:dkgunter@lbl.gov] 
Sent: Wednesday, May 19, 2004 8:24 PM
To: nm-wg@ggf.org
Subject: Re: [nm-wg] Reporting "packet" size for RTTs

Cottrell, Les wrote:
> This seems a pretty silly question, but when reporing the "packet" size for say ping RTT's do we report the ICMP payload (typically 56 by default) or the ICMP packet size with header (typically 64Bytes), or both or what?

the comment at the end of section 2.6 in the IPPM RFC

http://www.faqs.org/rfcs/rfc2681.html

says:

Comment: "ping" would qualify as a round-trip measure under this
    definition, with a Type-P of ICMP echo request/reply with 60-byte
    packets.  However, the uncertainties associated with a typical ping
    program must be analyzed as in the next section, including the type
    of reflecting point (a router may not handle an ICMP request in the
    fast path) and effects of load on the reflecting point.}

not sure that helps..

-Dan