From mboxrd@z Thu Jan  1 00:00:00 1970
From: Rick Jones <rick.jones2@hp.com>
Subject: Re: [PATCH v7 net-next 2/2] tcp: switch rtt estimations to usec resolution
Date: Wed, 26 Feb 2014 17:21:25 -0800
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References: <1393137487.2316.48.camel@edumazet-glaptop2.roam.corp.google.com> <alpine.LFD.2.11.1402230908210.1460@ja.home.ssi.bg> <1393178122.2316.50.camel@edumazet-glaptop2.roam.corp.google.com> <1393181458.2316.56.camel@edumazet-glaptop2.roam.corp.google.com> <1393216927.2316.62.camel@edumazet-glaptop2.roam.corp.google.com> <1393266251.2316.68.camel@edumazet-glaptop2.roam.corp.google.com> <alpine.LFD.2.11.1402242240290.1941@ja.home.ssi.bg> <1393280025.2316.76.camel@edumazet-glaptop2.roam.corp.google.com> <alpine.LFD.2.11.1402250056250.1941@ja.home.ssi.bg> <1393284682.2316.83.camel@edumazet-glaptop2.roam.corp.google.com> <20140224155130.4c286cca@samsung-9> <1393290667.2316.96.camel@edumazet-glaptop2.roam.corp.google.com> <1393292339.2316.98.camel@edumazet-glaptop2.roam.corp.google.com> <1
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Cc: David Miller <davem@davemloft.net>, Julian Anastasov <ja@ssi.bg>,
	Yuchung Cheng <ycheng@google.com>,
	netdev <netdev@vger.kernel.org>,
	Neal Cardwell <ncardwell@google.com>,
	Larry Brakmo <brakmo@google.com>
To: Stephen Hemminger <stephen@networkplumber.org>,
	Eric Dumazet <eric.dumazet@gmail.com>
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On 02/26/2014 05:09 PM, Stephen Hemminger wrote:
> Since srtt is scaled by 8 and is 32 bits, This does reduce the maximum
> possible RTT to 8 minutes or so. Which is fine, just wanted it to be
> noted.

I have encountered some situations recently, admittedly very 
pathological, where the RTT through a VPN connection was measured in 
minutes.  I don't think it got as high as 8 minutes, but it did get as 
high as three or so.  Also mentioned only for the record.

rick jones