CoNDIS question

Discussion in 'Windows Vista Drivers' started by Pavel A., Nov 8, 2005.

  1. Pavel A.

    Pavel A. Guest

    Dear NDIS Experts,

    I'm considering writing a CoNDIS miniport for a "point to point" network
    Basically it is like Ethernet, but it's media connect state is controlled by
    and user experience should be like dialing or connecting to WAN.
    Rather than rolling own "dialer" UI, I'd like to use what Windows provides.

    Now, from the messages in this NG, it seems that layering IM over CoNDIS
    miniports has some problems.

    So , is there a real risk in connection oriented solution?
    Will it break some important 3rd party stuff (firewalls, antiviruses...)?

    Pavel A., Nov 8, 2005
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  2. CoNDIS does not support IMs.

    But CoNDIS is only used between your driver and NDISWAN (PPP core), and no
    firewalls plug here - no fun in analyzing the PPP-compressed-and-crypted

    The interface where firewalls are plugged is between WANARP (protocol,
    really a plugin to TCPIP) and NDISWAN (the miniport edge of it). This is where
    the firewalls are plugged. The packets there are cleartext and have the fake
    Ethernet header added to them.

    This interface is not dependant on particular PPP miniport, and so no
    miniport (if properly written) will break the firewalls.
    Maxim S. Shatskih, Nov 8, 2005
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  3. Pavel A.

    Pavel A. Guest

    Thanks for reply Maxim,
    I'm afraid I don't fully understand this. The device is the real, physical netcard with a real MAC adress - not a "virtual"
    device like PPPoE or dialup adapters.
    Does NDISWAN always attach to any CoNDIS MAC?
    I'll just try to make such driver and play with it...

    Pavel A., Nov 9, 2005
  4. Does NDISWAN always attach to any CoNDIS MAC?

    Surely. NDISWAN has - among other things - a CoNDIS protocol lower edge for
    "TAPI proxy" family.

    Your CoNDIS WAN miniport must have a MCM upper edge for "TAPI" family.

    The entity which ties the stuff together is NDProxy.sys, who is a protocol for
    "TAPI" family and the call manager for "TAPI proxy" family. NDProxy also
    exposes the set of IOCTLs callable by user-mode TAPI stuff.

    NDProxy governs dialing and accepting calls, but the data transport is from
    your packet to NDISWAN. NDISWAN does PPP compression/crypto stuff, multiplexing
    based on protocol ID, and also IPCP stuff. It also has the IOCTL interface
    which is called by user-mode RAS DLLs.

    So, NDISWAN is always active. It is the PPP core.
    Maxim S. Shatskih, Nov 9, 2005
  5. Pavel A.

    Pavel A. Guest

    Thanks Maxim.
    Then co-ndis is not what I need - if some other flavors of co-ndis that
    do not involve PPP and let me handle ARPs don't exist.

    Pavel A., Nov 10, 2005
  6. Are you speaking about the PPP network adapter?
    Maxim S. Shatskih, Nov 10, 2005
  7. Pavel A.

    Pavel A. Guest

    Not exactly. it is "point to point" in sense that it connects exactly two nodes; there are
    no other nodes like in normal ethernet. But it does not utilise PPP protocol.
    Though PPP could work over this link as well.

    Pavel A., Nov 10, 2005
  8. Then emulate the modem over it - and PPP will work :)

    Otherwise, you will need 2 drivers - one for the card in general, another
    for PPP on this card.

    Also - why not use PPP? A good protocol. Why invent your own IP-over-point
    to-point protocol?
    Maxim S. Shatskih, Nov 10, 2005
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