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Old 10-05-2007, 07:24 AM
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Thumbs up Muti-NAI hack BUSTED: How to tether via Internet Sharing without a PAM plan

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-11/1/07-
As this is a rather lengthy thread to pour through, i've excerpted/posted the most important details into this (my first) post

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To bypass tether-detection for Internet Sharing: (from post #35 in this thread, courtesy of Luv2Chill: http://forum.ppcgeeks.com/showpost.p...5&postcount=35)

Those of you running Sprint ROMs should remove the following registry value:

[HKEY_LOCAL_MACHINE\Comm\InternetSharing
"Extension"="rilphone.dll"

Usual caveats about editing the registry apply here--don't do this unless you know how.
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Explanation is below:

I like (parens) and improper usage of single quotation marks to show 'emphasis'

Sprint employs tether-detection logic via a dynamic NAI domain prefix mechanism. This mechanism identifies the nature (tethered/untethered/datalink,etc) of a data connection request during the data authentication process. As Windows Mobile does not natively support such a mechanism, Sprint has elected to 'enhance'(cripple) Microsoft's extensible Internet Sharing (IS) application with pseudo-tether-detection 'logic' to approximate said mechanism: When in use, IS authenticates data sessions as 'tethered'. Fortunately, this 'logic' is implemented through a registry entry and .dll file, thus being (power)user-configurable.

As of ROM version 2.09, the 'logic' implemenation is flawed such that if a data session exists prior to invoking IS (data session has already authenticated as 'un-tethered'), IS simply NAT's the existing connection, rather than re-authenticating as 'tethered'. This explains the heretofore seemingly inconsistent connection successes/failures users without a PAM plan were experiencing.

The above registry tweak, discovered by Luv2Chill, bypasses Sprint's 'logic', allowing IS to work as provided by Microsoft: simple IP NAT of the device's data connection.


For those curious about how/why, below appear my relevant and correct/accurate discussion tidbits that were posted prior to Luv2Chill's tweak, with various clarifications interspersed. Again, i have excerpted/posted them here because several initial theories/posts (mine included) were dis-proven after trial and error, and until now, a reader had to read the entire thread to obtain accurate information. I hereby save readers from this necessity. Please be aware the original posts (besides this one) have not been edited for correctness, and thus may contain misinformation. They continue after the line of *asterisks* below.


[With a factory-fresh Titan/Mogul] Internet sharing WITHOUT a PAM (Phone As Modem) plan is possible if a data connection exists/is initiated (white or gray arrows above signal strength meter) prior to invoking the 'internet sharing' application. To be clear, it is NOT that one must connect with PIE before using ICS, it is that launching PIE is just a method of creating said necessary pre-existing data connection.
When ICS is invoked without a pre-existing data connection, ICS sees that M.IP 1 is NOT already connected and thus prefixes the NAI domain with 'pam', becoming 'username@pam.sprintpcs.com'. The phone then attempts to connect, and gets booted (error 67) when no PAM plan is found on the users account.
When ICS is invoked with a pre-existing data connection, ICS sees that M.IP 1 is already connected, and thus simply uses the existing data connection and shares it.

At NO POINT is M.IP 2 (or any other M.IP besides 1) used for PAM authentication.


It appears that, as far as authentication is concerned, there is no difference between the 'Sprint PCS' and 'Phone As Modem' connections. There is no correlation btw the error 67 (failure to authenticate) and the network connection chosen in 'Internet Sharing'. Regardless of which is selected, the error 67 only occurs when there is no EXISTING data connection.


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Original post:


just wrote a huge breakdown of this process and the #$&*#& backspace button took me back a page instead of back a space.. i'll see if i feel like explaining this process tomorrow from work. anyone want to encourage me? (Former sprint tier II (ATS) Tech support rep) (ebmorgan is sorely misinformed)

Last edited by hunterdg; 11-02-2007 at 05:39 AM. Reason: consolidate tweak/pertinent details on first page
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