The XCVR2450 hardware is incapable of full-duplex operation. It
*cannot* transmit and receive at the same time. 

On Wed, 01 Feb 2012
18:05:53 +0100, Florian Schlembach wrote: 

>>> We are now trying to
establish an TCP/IP connection between both USRP2s with the tunnel.py
script. Unfortunately, it says "Destination Host unreachable" when
pinging the other USRP. We should have set up the tunnel correct as some
packets are received and transmitted after having configured the IP
address. The pinged USRPs is indicating the received icmp packet but
there is still no confirmed ping-request though.
>> Short answer; dont
do that. Yes, this particular USRP is a network device, but that is
completely unrelated to the purpose of tunnel.py. You probably have to
play with routing tables to make this work...
> Why is that unrelated to
the purpose of tunnel.py? Shouldnt a simple ping request be a basic
application of using this TUN/TAP application? Anyway, we have now set
up the routing table correctly by using TUN instead of TAP. As we are
transmitting the ping from one of the USRPs, we are also receiving them
at the RX-USRP which is answering with a ping reply: RX-USRP: - TIMEOUT
Rx: ok = True len(payload) = 84 Tx: len(payload) = 84 send now! UTIMEOUT
- Observing the IP dataflow via Wireshark (at RX-USRP) confirms that.
However, we are NOT receiving this ping reply and the transmitting USRP.
It seems, like it cannot transmit and receive simultaneously. Exactky
the same happens if we swap the role of transmitting and receiving
USRPs. Anybody has an idea how we could overcome this problem?
Basically, we want to measure the latency of a "real" application.
_______________________________________________

  
_______________________________________________
Discuss-gnuradio mailing list
Discuss-gnuradio@gnu.org
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

Reply via email to