[178174] in North American Network Operators' Group
Re: OT - Small DNS "appliances" for remote offices.
daemon@ATHENA.MIT.EDU (Rob Seastrom)
Wed Feb 18 20:23:40 2015
X-Original-To: nanog@nanog.org
To: "Robert Webb" <rwebb@ropeguru.com>
From: Rob Seastrom <rs@seastrom.com>
Date: Wed, 18 Feb 2015 20:23:37 -0500
In-Reply-To: <6kuidte0ccrph68sp1cmbrwy.1424300924779@email.android.com>
(Robert Webb's message of "Wed, 18 Feb 2015 18:08:46 -0500")
Cc: "nanog@nanog.org >> 'NANOG list'" <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
"Robert Webb" <rwebb@ropeguru.com> writes:
> What I do not like about the Pi is the network port is on the USB
> bus and thus limited to USB speeds.
Pretty much all of the ARM boards have their ethernet ports on HSIC
channels (480mbit/sec, no-transceiver-phy USB for on-board use -
maximum length is 10cm).
The Pi-B shares the single HSIC channel with the USB hub for the
keyboard and mice. It seems from looking at block diagrams and lsusb
output that the ODROID U3 has an SoC with multiple HSIC channels and
dedicate one to to the ethernet (though the "bus" vs "port"
distinction is suspect).
pi@raspi-b ~ $ lsusb -t
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=dwc_otg/1p, 480M
|__ Port 1: Dev 2, If 0, Class=hub, Driver=hub/3p, 480M
|__ Port 1: Dev 3, If 0, Class=vend., Driver=smsc95xx, 480M
pi@raspi-b ~ $
root@odroid:~# lsusb -t
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=exynos-ohci/3p, 12M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=s5p-ehci/3p, 480M
|__ Port 2: Dev 2, If 0, Class=Vendor Specific Class, Driver=smsc95xx, 480M
|__ Port 3: Dev 3, If 0, Class=Hub, Driver=hub/3p, 480M
root@odroid:~#
But 480 is greater than 100, and none of the Pis have ethernet faster
than 10/100. The long pole in the tent is definitely not the USB, and
single stream tcp throughput is fine.
pi@raspi-b ~ $ curl -o /dev/null http://172.30.250.101/bigfile
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 989M 100 989M 0 0 11.1M 0 0:01:28 0:01:28 --:--:-- 11.1M
pi@raspi-b ~ $
-r
