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Setting up CME behind a NAT/PAT router possible?

Discussion in 'Voice' started by Septima77, Oct 9, 2009.

  1. Septima77

    Septima77 Nibble Poster

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    I have a cabin up in the mountains where cell phone reception is very bad. I have an internet connection in the cabin and was thinking of hooking up a cme router so that I can call home over the internet.
    The problem is that at home I have a broadband router that is secured by the ISP with its MAC address.
    Which means I can't unplug that router and hook the connection directly to my Cisco router.
    So, how do I overcome the NAT?

    I know I should avoid NAT with VoIP.... but, can it be done?

    The fun is of course making free calls to home and configure a Bat-phone in the cabin :)
     
    Certifications: CCNA CCNAS CCNAV
    WIP: CCVP
  2. BosonMichael
    Highly Decorated Member Award

    BosonMichael Yottabyte Poster

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    Why would you need to overcome the NAT?
     
    Certifications: CISSP, MCSE+I, MCSE: Security, MCSE: Messaging, MCDST, MCDBA, MCTS, OCP, CCNP, CCDP, CCNA Security, CCNA Voice, CNE, SCSA, Security+, Linux+, Server+, Network+, A+
    WIP: Just about everything!
  3. Septima77

    Septima77 Nibble Poster

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    The reasoning is as follows:
    When a connection is made from outside the LAN is not clear which device on the LAN the connection is meant to be established with. In this case there needs to some rule that tells the NAT router what to do with the incoming traffic, otherwise it will simply discard the traffic and no connection will be established. And since my NAT router, a French Sagem @3202, does not support a 'software DMZ' it cannot handle simple rules such as "pass all incoming connection requests to the device with i.e. addres 192.168.1.2".

    Seriously thinking about changing providers.
     
    Certifications: CCNA CCNAS CCNAV
    WIP: CCVP
  4. Septima77

    Septima77 Nibble Poster

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    Talked a technician from my ISP and there is (a secret) way to get to the advanced settings of the router and configure actions for incoming requests. Problem solved.
     
    Certifications: CCNA CCNAS CCNAV
    WIP: CCVP
  5. BosonMichael
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    BosonMichael Yottabyte Poster

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    But you'll have only one device that the cable modem would be sending the packets to: the router's IP address. Then the router figures out what to do with the packets. If your router can't handle that, then that's your router's problem, not your provider's. :)
     
    Certifications: CISSP, MCSE+I, MCSE: Security, MCSE: Messaging, MCDST, MCDBA, MCTS, OCP, CCNP, CCDP, CCNA Security, CCNA Voice, CNE, SCSA, Security+, Linux+, Server+, Network+, A+
    WIP: Just about everything!
  6. Septima77

    Septima77 Nibble Poster

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    You are right.
    Have not yet explored the details, but I can set up a DMZ Host IP address and firewall policies for incoming requests with statefull deep packet inspection.

    So, although the router is French (which means it is over-designed and under-performing :D) I think it is going to work.

    I will take my CCNAV test on the 19th.

    After that date I will have a closer look.
     
    Certifications: CCNA CCNAS CCNAV
    WIP: CCVP

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