[Simh] VAX XQ and wireless networking

[Jordi Guillaumes i Pons]

Al 17/11/12 22:04, En/na Sergey Oboguev ha escrit:
> In the latter case you'd need to find a way to tunnel 802.3 packets 
> over 802.11 or over generic TCP/IP. General approach would be to 
> attach SIMH XQ to Linux tap device on one side and hook tap/tun's 
> other side into tunneling software. VDE 
> (http://wiki.virtualsquare.org/wiki/index.php/VDE) does just that, but 
> I personally do not have experience using VDE. Furthermore, there is 
> some direct VDE support in the latest version of SIMH (assuming the 
> simulator executable is built with VDE option enabled). I have not 
> personally tried using it, but at a glance at the code, it looks like 
> it allows to connect XQ to VDE_SWITCH directly (using vde:port 
> syntax), not requiring tap device as an intermediary.
It does, and it works, but there is a caveat. I have not been successful 
bridging the tapx device which the vde switch exposes to the wlan 
physical interface. It is easily done with a real, wired ethernet, but 
not with a wlan. There is a solution. VDE comes with some support 
utilities which allow to "plug" into the virtual switch. Using vde_plug 
and dpipe (another VDE utility which provides two-way redirection 
between two unix processes) you can establish a ssh tunnel which acts as 
a transport pipe for the raw ethernet packages used by VDE. It works at 
level 2, so it should provide DECNET, LAT and LAVC connectivity (I have 
not tried the last one). As a bonus, it works with any IP link, 
including a tethered 3D link or even a POTS line.