GPRS IP address Assignment
These days we are working on a very interesting problem.
We want to establish direct communication between two phones over GPRS.
Its not a problem whe you are sending an SMS/CBS. Things get complicated
when you are trying to open a socket connection directly to the other phone.
because then you need to know the "IP Address" of the peer phone.
In GPRS address assignment is done dynamically - that means a phones IP keeps
changing - how often - I am not sure. So there needs to be a server which keeps
a record of all the IPs of all the phones which are online.
So If Alice wants to send a file to Bob ( excuse me for using the typical names from
computer security - but I love these names! - ) so Alice queries the central server
for Bob's IP. When Bob went online ( opened a server socket connection) it got to
know its IP address and published it to the the central server. Alice gets this IP fromthe server.
The problem is not solved yet.
The next problem becomes more basic one - how is the routing done?
How does my operators GGSN know where to rotue this packet destined
for IP address 203.bbb.ccc.ddd. How does it know whether to send to Vodafone's GGSN
or to send to O2's GGSN or to T-mobile's GGSN.
I dun think it should be an issue because the GGSNs in itself are just just routers in the internet.
We are testing it - lets see how it goes - if it works across operators - then it will rock.
will keep you updated
cheers
sourabhs
We want to establish direct communication between two phones over GPRS.
Its not a problem whe you are sending an SMS/CBS. Things get complicated
when you are trying to open a socket connection directly to the other phone.
because then you need to know the "IP Address" of the peer phone.
In GPRS address assignment is done dynamically - that means a phones IP keeps
changing - how often - I am not sure. So there needs to be a server which keeps
a record of all the IPs of all the phones which are online.
So If Alice wants to send a file to Bob ( excuse me for using the typical names from
computer security - but I love these names! - ) so Alice queries the central server
for Bob's IP. When Bob went online ( opened a server socket connection) it got to
know its IP address and published it to the the central server. Alice gets this IP fromthe server.
The problem is not solved yet.
The next problem becomes more basic one - how is the routing done?
How does my operators GGSN know where to rotue this packet destined
for IP address 203.bbb.ccc.ddd. How does it know whether to send to Vodafone's GGSN
or to send to O2's GGSN or to T-mobile's GGSN.
I dun think it should be an issue because the GGSNs in itself are just just routers in the internet.
We are testing it - lets see how it goes - if it works across operators - then it will rock.
will keep you updated
cheers
sourabhs
posted by siriusblack at 5:09 PM
1 Comments:
Hi,
Your article is an interesting read and will help a lot in p2p applications over mobile!
I am stuck in a much simpler problem and you seem to be the expert here. How do I get the IP address of a mobile phone over GPRS? The question may sound by a newbie, but I want to prototype an application where various clients (symbian, windows mobile etc.) send their IP to a server over GPRS. Do you know of any such way or a working prototype with this capability?
Your help will be appreciated.
Thanks
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