Re: [MM] grabbing QMI/WDM ports

[Marius Bjørnstad Kotsbak <marius kotsbak gmail com>]

On 11. april 2012 16:07, Bjørn Mork wrote:
> Marius Bjørnstad Kotsbak<marius kotsbak gmail com>  writes:
>
> > I might also get time to test this as i just received my ZTE 820D
> > modem. But I just wonder what the point of doing this is? Is it giving
> > better performance
> In my testing with a Huawei E392 (which uses the same Qualcomm chipset
> as the ZTE 820D) I've never been able to exceed 8 Mbits/s upstream when
> using PPP and the option driver.  I've seen upstream bandwidths as high
> as 30+ Mbits/s when using the network interface and the qmi_wwan driver.
> So better performance is certainly a main argument for dropping PPP for
> me.
>
> I've not done any actual analysis of why the PPP upstream bandwith is
> limited. I'm guessing that modem packet processing may be the primary
> limiting factor, but I don't know this. Comments and test results are
> appreciated.  What data rates are you getting?


I measured 30-40 Mbits/s at max here in Trondheim, Norway using NetCom, 
although I measured nearly 50 Mbits/s using the ZTE MS Windows driver. 
The upstream speed is though lower than I was used to get using the old 
Samsung modem (which had a terrible firmware I developed the "kalmia" 
module for).

> Note that the downstream bandwidth isn't affected (to the same degree at
> least).  But that is reasonable, as adding a PPP header to the received
> packets is no work at all...

Ah, then my observations above makes sense. At 28,4 Mbps downtload speed 
I only get 1,31 Mbps right now.


> > or more possibilities (checking signal quality
> > while connected?)? The modem works great in Ubuntu 12.04 using the 3.2
> > kernel without the qmi_wwan module (using just option module).
> I believe QMI exposes a lot more than what's available through the AT
> command interface, but why care as long as the AT interaface provides
> more than enough for normal usage?  So yes, the modem works just fine
> with PPP and the option driver.  You don't really need another driver.
> But what's the fun in that :-)

Sure, but it is very nice to have a working backup way to connect out of 
the box using Network Manager until the required plugins and kernel code 
is in place.

> Another issue, which I just noticed yesterday, and which may be purely a
> Huawei firmware issue: I am completely unable to do IPv6 connections
> using PPP.  The PDP context is reset to "IP" (from "IPV6" or "IPV4V6")
> whenever I issue an "ATDT*99#" command.  I'm not claiming that IPv6
> works flawlessly using the qmi_wwan driver either (in fact it doesn't
> work at all without additional hacks), but at least it is possible to
> make it work.  Further research is required before this goes anywhere
> near mainstream, though.

In Network manager, I don't find any IPv6 settings when using PPP.

--
Marius