Re: PPPoE and PPPoA as Modem Driver
Re: PPPoE and PPPoA as Modem Driver
- Subject: Re: PPPoE and PPPoA as Modem Driver
- From: email@hidden
- Date: Thu, 31 Jan 2002 14:34:40 -0500
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Take a look at the software components in each case, with the new
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code that you have to write marked with a *.
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Option A Option B
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-------- --------
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Remote Access Remote Access
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| |
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OT serial shim TPI to DLPI (*)
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| |
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USB serial shim USB Ethernet shim
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USB driver (*) USB driver
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The problem with option A is the double shim business. OT shims to
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USB serial which shims to your driver. This can get very confusing
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very quickly, especially as each shim is essentially a black box:
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there's no easy way to debug the shim's operation because you don't
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have source for each shim. I was once called in to debug a problem
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with an Apple driver structured like this and it wasn't pretty
But ... isn't this the case for ALL usb modems? From the system's
perspective, we won't be exposing ourselves as anything but a modem.
I'm not trying to argue one way or the other ... we proposed a solution
based on Option B to our customer. They already have a Windows solution
using Option A so they want to know why we don't do that for MacOS. So,
I want to make sure I can give them a valid explanation.
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Yes. However, given the existance of the QTunnel sample (if you
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don't have a copy, I can send one along -- it shows an example of how
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the configurator, port scanner, configuration helper library, and
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STREAMS module work together), I don't consider this to be a big win.
Please do, I do not have QTunnel. I saw it mentioned in OTAPC but I
didn't know it was something that was available.
Thanks,
-Chris