NDIS IM driver for analog modem???!!!

Home Forums Discussions General Discussion NDIS IM driver for analog modem???!!!

Viewing 6 posts - 1 through 6 (of 6 total)
  • Author
  • #4887

    Why no one is answering my question???

    Hello e.b.

    I am comp. sci. student and doing a project on firewalls.
    I am new to driver writing and have started working with ddk a week ago. I am writing a NDIS IM driver for doing packet filtering…
    however the driver will work for network cards only!!! Can the driver also be made to work with alalog modems(ones that are attached to serial port) and if yes how???
    Can it bind itself with with modem driver insted of miniport NIC driver???
    What changes do I need to make in the IM driver???
    Can I modify the PassThru example given in Win2000 DDK to make it work with analog modems?
    If yes will it still be compatiable with NDIS??
    I know some of the questions may sound strange but bare with me as I am new to kernel programming!!!
    I would like to hear from all who have something to suggest to me…
    Thanks for your time…


    Why do thing your IM driver will not handle traffic from modems? Look at QoS driver. It is IM mininport but it filters modem`s traffic 🙂
    All modem are represented as one NIC with several MAC address, so you can deal with them.


    Hello Taras

    Thankyou for reply.
    As I said I am new to kernel programming so bear with me if my questions sound vague. 😕 😳
    I am not able to get a clear pic. of the whole thing…
    Since I am writing NDIS IM driver it is suppose to bind itself with NDIS miniport drivers. However modem driver may not be a NDIS miniport driver!!!(I hope I am making sence).
    I have a 56Kbps modem which is attached to COM port 2.(one that makes noice when connecting to the net 😆 )
    Now can my IM driver filter traffic coming from this modem and if yes how?
    I know I am asking too much but can you tell me how the whole thing works in a bit detail.
    Also suggest me some literature/reading material.
    Thanking you and hoping for reply…
    Parth Mehta


    Look at scheme. Your IM miniport driver will be inserted bettween “transport” and “802.3”. You will not see any modems, but you will see a virtual NIC named “NDISWANIP” which work as multiport NIC. So your driver can work as firewall perfectly


    Hello Taras

    Thankyou for the reply.
    I got it. Now final question. Which is a better way to develop a kernel level firewall – NDIS hooking or IM driver???

    I am not able to take a decision on this!!!
    What parameters should I consider when taking the decision?

    Microsoft doesnot support NDIS hooking…so it can change the undocumented data structures used by NDIS hooking any time.

    So I was having a debate with my friend over this topic (who favours hooking method).

    Can am IM driver be built that is atleast source compatiable wiht Win98?

    Why do most commertial personal firewalls use NDIS hooking when it can be done with IM driver?



    Why do most commertial personal firewalls use NDIS hooking when it can be done with IM driver?

    IMHO This question is asked by enyone who deal with filtering algorithm
    If you are developing your apps for NT, I think it more easy and better to use IM miniport. My opinion that NDIS hooking is legacy of cross plaform developing for NT and 9x that was actual some yaers ago.

    But I use NDIS hooking in my project. It is paradox. 🙂

Viewing 6 posts - 1 through 6 (of 6 total)
  • You must be logged in to reply to this topic.