Android RIL - RAW IP GPRS & Multiple APN Ipaddress

[ShivaP]

HI all,

I would like to try again getting some help from forum -

1) How is RAW IP GPRS mode handled in Android. In Win Mobile there's
Virtual Ethernet Miniport & WWAN NDIS Miniport adapter to take care of
this. How this happens in Android.? Is there any doc / link related to
this.

2) Multiple APN(Primary PDP): when GPRS context is activated for 2
different APNs, and if the network for the 2 APNs assigns Same IP
Address(Theoritically), then how the connection manager handles such
situation in Android.

Can somebody throw more light on this..

Thanks & Regards,
Shiva Prasad

[Robert Greenwalt]

Hi Shiva,

On question 1, do you mean tethering your laptop/desktop through a RNDIS connection exposed by the android device to forward IP over GPRS?  That is not currently supported.  If that's not what you mean can you explain further?

On 2, the telephony code and ConnectivityManager don't currently support simultaneous live PDP contexts, so 2 with the same IP is not yet an issue.  I would suppose that only 1 can be the default route and the other would have to be explicitly bound at the socket level to send packets over it.

R

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[Shiva Prasad]

Hi Robert,

Thanks for your response.
it's not related to using Android phone as modem for GPRS Connection
from a desktop through RNDIS.

Question 1: is regarding sending a Raw IP packet coming from TcP/IP
without PPP involved in a GPRS connection. The RAW ip packet typically
coming from tcp/ip would be put into a MUX DLC channel by WWAN Driver,
which will expose a virtual ethernet interface to tcp/ip.

This is similar to a mechanism in windows mobile NDIS based GPRS,
where no PPP comes in picture, directly RAW IP packet coming from TCP/
IP is sent to the MUX DLC through WWAN adapter driver and forwarded to
GPRS Modem.

Please see the link below:
http://msdn.microsoft.com/en-us/library/ee481897.aspx

Is there a similar mechanism in Android using some WWAN network
interface driver binding to tcp/ip and below end with a MUX DLC
Having PPP for GPRS would be a overhead for high speed data supporting modem.

Question 2:
Please see the roadmap in which it is mentioned simultaneous multiple
APN supported added in Q4 2008
http://source.android.com/roadmap

Please let me know if you need more information.

>> android-porti...@googlegroups.com<android-porting%2Bunsu...@googlegroups.com>
>> website: http://groups.google.com/group/android-porting
>>
>

[Robert Greenwalt]

Hi Shiva,

On Q1, I believe this implementation detail is hidden below our Radio Interface Layer (RIL) and that code typically comes from the radio hardware provider or a hardware integrator.  I think you certainly could create such an interface, but I don't think we have it today.

On Q2, we did not achieve that goal and still have not - I don't know who puts together those roadmaps but one projecting future action in q4 of 08 is obviously obsolete..

R

[Mikkel Christensen]

Hi,

The Raw IP interface would indeed needed to be created by the vendor
of the wireless modem.
It would be a Linux kernel driver that exposes a "net_device" to the
Linux IP stack. If you are using a USB modem you might be lucky and a
IP network device driver could exist. You will have to check that in
the Kernel source.

You can find many references to "net_device" online like here:
http://www.xml.com/ldd/chapter/book/ch14.html

There would also be a need for multiplexer software that can create
several logical channels on the physical channel between the modem and
the apps processor.
This could be 3GPP 27.010, multiple USB endpoints or propietary
protocol.

Best regards,
Mikkel

On Feb 8, 11:21 am, Robert Greenwalt <rgreenw...@google.com> wrote:
> Hi Shiva,
>
> On Q1, I believe this implementation detail is hidden below our Radio
> Interface Layer (RIL) and that code typically comes from the radio hardware
> provider or a hardware integrator.  I think you certainly could create such
> an interface, but I don't think we have it today.
>
> On Q2, we did not achieve that goal and still have not - I don't know who
> puts together those roadmaps but one projecting future action in q4 of 08 is
> obviously obsolete..
>
> R
>

> On Fri, Feb 5, 2010 at 11:53 PM, Shiva Prasad <tsshivapra...@gmail.com>wrote:
>
>
>
> > Hi Robert,
>
> > Thanks for your response.
> > it's not related to using Android phone as modem for GPRS Connection
> > from a desktop through RNDIS.
>
> > Question 1: is regarding sending a Raw IP packet coming from TcP/IP
> > without PPP involved in a GPRS connection. The RAW ip packet typically
> > coming from tcp/ip would be put into a MUX DLC channel by WWAN Driver,
> > which will expose a virtual ethernet interface to tcp/ip.
>
> > This is similar to a mechanism in windows mobile NDIS based GPRS,
> > where no PPP comes in picture, directly RAW IP packet coming from TCP/
> > IP is sent to the MUX DLC through WWAN adapter driver and forwarded to
> > GPRS Modem.
>
> > Please see the link below:
> >http://msdn.microsoft.com/en-us/library/ee481897.aspx
>
> > Is there a similar mechanism in Android using some WWAN network
> > interface driver binding to tcp/ip and below end with a MUX DLC
> > Having PPP for GPRS would be a overhead for high speed data supporting
> > modem.
>
> > Question 2:
> > Please see the roadmap in which it is mentioned simultaneous multiple
> > APN supported added in Q4 2008
> >http://source.android.com/roadmap
>
> > Please let me know if you need more information.
>

> > On 2/5/10, Robert Greenwalt <rgreenw...@google.com> wrote:
> > > Hi Shiva,
>
> > > On question 1, do you mean tethering your laptop/desktop through a RNDIS
> > > connection exposed by the android device to forward IP over GPRS?  That
> > is
> > > not currently supported.  If that's not what you mean can you explain
> > > further?
>
> > > On 2, the telephony code and ConnectivityManager don't currently support
> > > simultaneous live PDP contexts, so 2 with the same IP is not yet an
> > issue.
> > >  I would suppose that only 1 can be the default route and the other would
> > > have to be explicitly bound at the socket level to send packets over it.
>
> > > R
>

> > > On Thu, Feb 4, 2010 at 9:13 PM, ShivaP <tsshivapra...@gmail.com> wrote:
>
> > >> HI all,
>
> > >> I would like to try again getting some help from forum -
>
> > >> 1) How is RAW IP GPRS mode handled in Android. In Win Mobile there's
> > >> Virtual Ethernet Miniport & WWAN NDIS Miniport adapter to take care of
> > >> this. How this happens in Android.? Is there any doc / link related to
> > >> this.
>
> > >> 2) Multiple APN(Primary PDP): when GPRS context is activated for 2
> > >> different APNs, and if the network for the 2 APNs assigns Same IP
> > >> Address(Theoritically), then how the connection manager handles such
> > >> situation in Android.
>
> > >> Can somebody throw more light on this..
>
> > >> Thanks & Regards,
> > >> Shiva Prasad
>
> > >> --
> > >> unsubscribe:

> > >> android-porti...@googlegroups.com<android-porting%2Bunsubscribe@­googlegroups.com>
> > <android-porting%2Bunsu...@googlegroups.com<android-porting%252Bunsubsc­ri...@googlegroups.com>
>
> > >> website:http://groups.google.com/group/android-porting- Hide quoted text -
>
> - Show quoted text -