SMS PDU sender location

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juky - 05 Apr 2007 08:44 GMT

Dear all,

i would like to know if there is way by reading SMS in PDU format to
find out some information which can tell me where the SMS was
originated (mostly from which country). Any idea how to get such
information?

Thanks a lot

Juky

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John Henderson - 05 Apr 2007 09:15 GMT

> i would like to know if there is way by reading SMS in PDU
> format to find out some information which can tell me where
> the SMS was originated (mostly from which country). Any idea
> how to get such information?

The PDU will include the SMSC (message centre) of message
lodgement. This will be in international format (beginning
with a country code). Also the SMSC timestamp will be in "raw"
PDU format, showing the date/time of lodgement in the
originator's local time, plus the offset from UTC.

John

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juky - 05 Apr 2007 10:04 GMT

Maybe i have a wrong idea about SMSC, sorry. Isn't SMSC related to my
home operator and always the same? If i am in roaming in another
country the SMSC set in PDU when i send an SMS is related to the
roaming operator where i am currently conneted or my original home
operator ?

Thx

> > i would like to know if there is way by reading SMS in PDU
> > format to find out some information which can tell me where
[quoted text clipped - 8 lines]
>
> John

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John Henderson - 05 Apr 2007 11:10 GMT

> Maybe i have a wrong idea about SMSC, sorry. Isn't SMSC
> related to my home operator and always the same? If i am in
> roaming in another country the SMSC set in PDU when i send an
> SMS is related to the roaming operator where i am currently
> conneted or my original home operator ?

Yes, roaming complicates things. As far as I know, it's your
home network's SMSC which stamps the message. But I have not
confirmed this behaviour myself.

John

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juky - 05 Apr 2007 12:29 GMT

I just took a quick test, SMSC is always set as my home network even
if i am in roaming, so seems there is no way to discover from when SMS
was sent.

Juky

> jukywrote:
> > Maybe i have a wrong idea about SMSC, sorry. Isn't SMSC
[quoted text clipped - 8 lines]
>
> John

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Oscar - 05 Apr 2007 12:44 GMT

Hi,

When you are roaming, the message is sent via an International Gateway
in that country towards your own SMSC. This Gateway has its own address,
that contains the country code.

I believe this address is also still available in the GSM package sent
to your mobile, but if the mobile stores it I am not sure.

Oscar

> I just took a quick test, SMSC is always set as my home network even
> if i am in roaming, so seems there is no way to discover from when SMS
[quoted text clipped - 14 lines]
> >
> > John

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John Henderson - 05 Apr 2007 21:00 GMT

> When you are roaming, the message is sent via an International
> Gateway in that country towards your own SMSC. This Gateway
[quoted text clipped - 3 lines]
> package sent to your mobile, but if the mobile stores it I am
> not sure.

There's certainly provision for only a single SMSC address in
the stored MT PDU. And that can differ from the SMSC address
configured into the sending phone, even without roaming. A
certain amount of redirection seems normal, even if only to
allow a carrier to spread the load across several SMSCs which
have a single nominal access address.

John

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juky - 06 Apr 2007 08:22 GMT

Seems there is no much i can do to get sms tracking. The originator
location is not possible to identify just by reading SMSC address in
MT PDU. It always shows SMSC address configurated into the sending
mobile (roaming or not). All this way just to get prove a certain SMS
was sent from a specific country.

> > When you are roaming, the message is sent via an International
> > Gateway in that country towards your own SMSC. This Gateway
[quoted text clipped - 12 lines]
>
> John

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Oscar - 07 Apr 2007 12:00 GMT

Yep,

And since Juky wants to find out from which country the SMS was sent,
you need to look at the originating MSC address in stead of the SMSC,
but if this is stored in the mobile phone.

You can call your mobile telephone provider, if it keeps statistical
logging, he might be able to see where the SMS was coming from.

Oscar

> > When you are roaming, the message is sent via an International
> > Gateway in that country towards your own SMSC. This Gateway
[quoted text clipped - 12 lines]
>
> John

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