Cannot ping two mobiles within same GPRS network?

Hi,

I am trying to write an application to read/write information between
two mobile phone which was connected to GPRS network. But I found that
when two phone online and acquired their own IP 10.209.xxx.xxx, they
can't ping each other even they are connected to the same network
provider. I am using vxUtil ('Cambridge - vxUtil'
(http://www.cam.com/vxutil.html)).

Please help to provide me some information about this issue.

Thanks

Regards,
KF


------------------------------------------------------------------------
View this thread: http://www.wirelessforums.org/showthread.php?t=37297
http://www.wirelessforums.org

On Mon, 21 Jan 2008 22:35:26 -0500, kingfisher
<kingfisher.33kzi1@no-mx.wirelessforums.org> wrote:

>I am trying to write an application to read/write information between
>two mobile phone which was connected to GPRS network. But I found that
>when two phone online and acquired their own IP 10.209.xxx.xxx, they
>can't ping each other even they are connected to the same network
>provider. I am using vxUtil ('Cambridge - vxUtil'
>(http://www.cam.com/vxutil.html)).
>
>Please help to provide me some information about this issue.

I have no particular knowledge of how network operators implement data
connectivity but it's quite possible that they have several separate
networks within the 10.*.*.* address space, each with its own route
out the the Internet. There may well be no TCP/IP route between two
mobile phones on GPRS and the operators may filter inbound connections
in any case. On balance, I'd be surprised if pinging between mobile
phones did work.

Incidentally, the www.wirelessforums.org forum you're using is a
parasitic interface to usenet. You'd be better off using usenet
directly. This newgroup has nothing to do with the forum through
which you posted.

Mike.

In article <kingfisher.33kzi1@no-mx.wirelessforums.org>,
kingfisher.33kzi1@no-mx.wirelessforums.org says...
>
> Hi,
>
> I am trying to write an application to read/write information between
> two mobile phone which was connected to GPRS network. But I found that
> when two phone online and acquired their own IP 10.209.xxx.xxx, they
> can't ping each other even they are connected to the same network
> provider. I am using vxUtil ('Cambridge - vxUtil'
> (http://www.cam.com/vxutil.html)).
>
> Please help to provide me some information about this issue.
>

Being at the wrong end of a ping flood or SYN flood attack could be
painful in more ways than one considering the price of GPRS on some
networks.

I think as a result such things are blocked which would include incoming
connections. The two sides could connect via a proxy though.

I think some networks support static IP addresses though.

Steve.

In article <kingfisher.33kzi1@no-mx.wirelessforums.org>,
kingfisher.33kzi1@no-mx.wirelessforums.org says...
>
> Hi,
>
> I am trying to write an application to read/write information between
> two mobile phone which was connected to GPRS network. But I found that
> when two phone online and acquired their own IP 10.209.xxx.xxx, they
> can't ping each other even they are connected to the same network
> provider. I am using vxUtil ('Cambridge - vxUtil'
> (http://www.cam.com/vxutil.html)).
>
> Please help to provide me some information about this issue.

I don't think it's possible.
--
Regards
Jon

"Mike" <mike@kempston.net> wrote in message
news:isjbp39d96q994q8lac9d0cbhv7h468p55@news.kemps ton.net...
> On Mon, 21 Jan 2008 22:35:26 -0500, kingfisher
> <kingfisher.33kzi1@no-mx.wirelessforums.org> wrote:
>
>>I am trying to write an application to read/write information between
>>two mobile phone which was connected to GPRS network. But I found that
>>when two phone online and acquired their own IP 10.209.xxx.xxx, they
>>can't ping each other even they are connected to the same network
>>provider. I am using vxUtil ('Cambridge - vxUtil'
>>(http://www.cam.com/vxutil.html)).
>>
>>Please help to provide me some information about this issue.
>
> I have no particular knowledge of how network operators implement data
> connectivity but it's quite possible that they have several separate
> networks within the 10.*.*.* address space, each with its own route
> out the the Internet.

Indeed, but in theory that would then be the path between them. You can get
some very convoluted paths sometimes (e.g. after the Canadian ice storm).

What is probably the case is that the GPRS network stops the rest of the
world seeing the IP address of individual phones, the phones on the other
hands should be able to see most of the net, so indirect connection would be
possible.

> There may well be no TCP/IP route between two
> mobile phones on GPRS and the operators may filter inbound connections
> in any case. On balance, I'd be surprised if pinging between mobile
> phones did work.

Agreed otherwise loads of GPRS bandwidth would be wasted.

>
> Incidentally, the www.wirelessforums.org forum you're using is a
> parasitic interface to usenet. You'd be better off using usenet
> directly. This newgroup has nothing to do with the forum through
> which you posted.
>
> Mike.
>

On 2008-01-24, R. Mark Clayton <nospamclayton@btinternet.com> wrote:
> "Mike" <mike@kempston.net> wrote:
>> I have no particular knowledge of how network operators implement data
>> connectivity but it's quite possible that they have several separate
>> networks within the 10.*.*.* address space, each with its own route
>> out the the Internet.
>
> Indeed, but in theory that would then be the path between them. You can get
> some very convoluted paths sometimes (e.g. after the Canadian ice storm).
>
> What is probably the case is that the GPRS network stops the rest of the
> world seeing the IP address of individual phones, the phones on the other
> hands should be able to see most of the net, so indirect connection would be
> possible.

When you establish an Internet connection from your phone you end up
with a point-to-point connection between the phone and (one of) the
router(s) the Access Point Name names (what's that called, a GGSN?).
Your reachability is entirely dependent on what that router allows
you to reach.

It is quite possible that the router is configured to forward all net 10
packets that are destined to a global Internet address through NAT, and
to forward all packets coming from NAT to a net 10 address, but not to
forward packets directly from one net 10 address to another. This would
be an explicit choice by the operator not to allow phones to talk directly
to each other.

Dennis Ferguson

Assuming you could get it to work who would pay for the ping response?


------------------------------------------------------------------------
View this thread: http://www.wirelessforums.org/showthread.php?t=37297
http://www.wirelessforums.org

On Thu, 24 Jan 2008 14:33:39 -0000, "R. Mark Clayton"
<nospamclayton@btinternet.com> wrote:

>
>"Mike" <mike@kempston.net> wrote in message
>news:isjbp39d96q994q8lac9d0cbhv7h468p55@news.kemp ston.net...
>> On Mon, 21 Jan 2008 22:35:26 -0500, kingfisher
>> <kingfisher.33kzi1@no-mx.wirelessforums.org> wrote:
>>
>>>I am trying to write an application to read/write information between
>>>two mobile phone which was connected to GPRS network. But I found that
>>>when two phone online and acquired their own IP 10.209.xxx.xxx, they
>>>can't ping each other even they are connected to the same network
>>>provider. I am using vxUtil ('Cambridge - vxUtil'
>>>(http://www.cam.com/vxutil.html)).
>>>
>>>Please help to provide me some information about this issue.
>>
>> I have no particular knowledge of how network operators implement data
>> connectivity but it's quite possible that they have several separate
>> networks within the 10.*.*.* address space, each with its own route
>> out to the Internet.
>
>Indeed, but in theory that would then be the path between them. You can get
>some very convoluted paths sometimes (e.g. after the Canadian ice storm).

I don't think so, because the 10.0.0.0/8 network isn't routeable on
the Internet. For that to work, the network gateways would have to
route local addresses between themselves, keeping the traffic on the
isolated network and, while possible, I can't see the operators doing
it.

Mike.

On Thu, 24 Jan 2008 06:10:31 -0800 (PST), wkyau2000@gmail.com wrote:

>Beside of the ping being blocked, does it mean that we can't use/
>develop any application to send/receive like UDP packet within two
>mobile phone in GPRS network?

It quite possibly does mean that as far as direct phone-to-phone
communication is concerned. You'd have to experiment or ask the
network operator (if you can find someone to talk to at the network
operator who even understands the question!).

If I was doing this for a commercial application, I'd probably set up
a central server on the Internet to which the phones connect and
establish a communication channel using TCP. The phones would probably
have to poll the server regularly to keep the NAT active and prevent
the network from closing the connection. Messages between phones
could then be passed via the central server. This would be simple to
implement although would require a dedicated server and may not scale
well.

Mike.