On 10/31/2011 06:01 PM, Tuan (Johnny) Ta wrote:
I have been running into problems using tunnel.py as
well so instead of creating a new post I thought I'll just
continue this thread.
My setting:
USRP2
XCVR2450
Ubuntu 10.04 (32bit)
The problem I have is that after running tunnel, whenever I
do ping, my system gets stuck on the ARP exchange. Say A wants
to ping B. A broadcasts an ARP packet to find the MAC address of
B's IP. B gets the ARP request, immediately sends an ARP
response back to A with its MAC. However, in my system, A never
gets the ARP reply.
I seriously can't think of a reason for this. I can guess a
possible cause is that B sends the ARP reply too quickly that A
doesn't have enough time to go from transmit mode to receive
mode (XCVR2450 is a half-duplex daughterboard). But I don't know
how to verify this hypothesis.
Can anyone help me?
Thank you,
Johnny
We used to have this problem "back in the day" with packet-radio,
using analog FM transceivers--they were often notoriously sluggish
in turning around the TX/RX logic.
You might try zero-stuffing the TX frames--that's basically what we
did back in the day. Although the XCVR2450 short turn around fairly
quickly, it's not infinitely quick.
--
Marcus Leech
Principal Investigator
Shirleys Bay Radio Astronomy Consortium
http://www.sbrac.org