Re: [Discuss-gnuradio] TUN/TAP interface advantage

[Josh Blum]

On 09/15/2012 11:45 PM, usrp n210 wrote:
> Is there any advantage to use TUN/TAP interface ?

Tun/tap is a convenient way to get access to the network stack from
userspace. Unfortunately the benchmark* apps abuse tun/tap as a mac
layer, which is precisely the wrong thing to do.

For example:
https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_over_wireless_networks

(if you wait a few days, there will be some sweet work released with MAC
layer + message passing in GRC. Stay tuned...)

-josh

> As 802.11bbn also uses TUN/TAP interface.
> But I think in the tun/tap performance degrades as we send the packet back
> to user process?
> Therefore I compare results with benchmark_xx.py in /ofdm  with tunnel.py
> in /ofdm.
> In results benchmark_xx.py do not give consistent throughput (i.e. it
> varies on channel) but tunnel.py gives 100% throughput irrespective of
> channel
> Will there be any valid reason for this ?
> If I want to implement 2-way communication in USRP should I use TUN/TAP
> interface?
>