Raspberry Pi Network Performance

[Malcolm Matalka]

Hello,

I'm having fun playing with FreeBSD running a Raspberry Pi.  I've set
mine up as a WiFi access point routing over a VPN.  I am experiencing
a slow network connection through the entire chain, but each individual
component functions at a reasonable speed.

I am wondering what I can do, if anything, to help improve the
performance.

Details:

My setup is:

Laptop (WiFi) -> USB Dongle -> Raspberry Pi (OpenVPN) -> Ethernet -> Router -> Internet

I have done the following experiments, transferring 150meg ISO around:

End-to-end - ~60 KB/s - Downloading the ISO on my laptop from a website.

Laptop (WiFi) -> Router -> Ethernet -> Raspberry Pi - ~1.5MB/s - Scping
a file to /dev/null on the RPi

Laptop (WiFi) -> USB Dongle -> Raspberry Pi - ~1MB/s - Scping a file to
/dev/null on RPi

Raspberry Pi (OpenVPN) -> Ethernet -> Router -> Internet - ~1MB/s -
Downloading the ISO from the end-to-end experiment

Raspberry Pi (OpenVPN) -> Ethernet -> Router -> Internet - ~1MB/s
AND
Laptop (WiFi) -> USB Dongle -> Raspberry Pi - ~1MB/s

In this experiment I tested hitting both interfaces with traffic at the
same time.  There was little noticeable degradation in the individual
performances.

$ uname -a

FreeBSD gizmo 10.1-RELEASE-p6 FreeBSD 10.1-RELEASE-p6 #1 r279698: Sat
Mar 7 16:07:29 CET 2015
mmatalka at bsd-junkyard:/usr/home/mmatalka/projects/freebsd/obj/arm.armv6/usr/home/mmatalka/projects/freebsd/src/sys/RPI-B-GIZMO
arm

# ipfw list
00100 nat 1 ip from any to any via tun0
09999 allow ip from any to any
65535 deny ip from any to any

While each individual piece operates about as fast as I would expect,
the end-to-end performance is an order of magnitude slower.

If there are any other experiments I should do, let me know.

What can I do to determine what is going on?

Thank you,
/Malcolm