Will a VoIP hardware phone work behind two NATs?

Discussion in 'UK VOIP' started by bluebird44, Jul 6, 2007.

  1. bluebird44

    bluebird44 Guest

    Internet <---> Wireless Router <---> Windows PC <----> VoIP

    VoIP phone connected to PC via crossover Ethernet cable

    First time user, I bought gradwell.com's VoIP service this week, and
    works perfectly with X-Lite behind a broadband router (Virgin Media
    aka NTL - 1 IP) but now I want to buy a dedicated hardware VoIP phone
    (Snom 370). I'd like to the Snom phone to my PC via cross-over
    Ethernet cable so that it can connect to the wireless network and then
    to Gradwell's server.

    Will this work? If not, what other way can I connect the Snom phone to
    my wireless network?
    bluebird44, Jul 6, 2007
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  2. bluebird44

    Graham Guest

    Its like posting to Usenet via Google Groups, it works but
    it's not very elegant.
    Doesn't that wireless router have any Ethernet ports?
    Graham, Jul 6, 2007
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  3. bluebird44

    bluebird44 Guest

    It does but the router is downstairs and PC and VoIP phone is
    upstairs. Connecting VoIP phone to PC's ethernet port is just
    temporary (few months).

    I've looked into wireless bridge but it looks like a headache.
    bluebird44, Jul 6, 2007
  4. bluebird44

    Graham Guest

    Does it have to be a Snom?
    Can't you plug an ATA into the router, and a DECT
    base into the ATA?
    Graham, Jul 6, 2007
  5. bluebird44

    mymail Guest

    Does it need to be the phone you have mentioned why not get a WiFi
    phone which you can take anywhere in the house and even outside
    providing you do not go further away from your router than 50 m I
    think it is . I have bought two of these this year and it as proved to
    be the best move I have ever made wouldn't be without them and would
    not even consider going back to using an ATA now .
    mymail, Jul 6, 2007
  6. bluebird44

    Mark Guest

    Better still is Graham's suggestion elsewhere in this thread. My DECT

    - gives far more reliable and extensive coverage than does my wireless
    - runs on AA cells.
    - base station has a ringer in it, too.
    Mark, Jul 6, 2007
  7. I guess you're using Internet connection sharing on the PC? In which case,
    it might work, but SIP has issues going through NAT at the best of times,
    and putting it through 2 NAT routers is just asking for trouble.

    If you want to go this route, seriously do look into using a WiFi
    bridge. Small box and antennae which you can place somewhere convenient
    to pick up a good signal with an Ethernet socket on which you can connect
    to a switch, then hang multiple Ethernet devices on.

    However, I'm really not a fan of carrying VoIP over WiFi. I do it myself,
    with a WiFi VoIP phone (UT Starcom) but it's problematic at the best of
    times. Just one application doing a big download on the PC will affect
    voice quality over WiFi.

    If it doesn't have to be a Snom phone, (and the 370 is a big expensive
    phone!!!) then what about a DECT system? the Siemens C460IP is a great
    unit, and if you're looking for multiple SIP account support, then the
    S450IP is the unit to have.

    You then have the advantage that from one handset you can select either
    the Analogue line or the SIP line(s). The base unit is separate from the
    handsets, and the base unit has both an analogue port and an Ethernet
    port, so put the base station next to where the Wireless router is and
    connect it in via Ethernet.

    And if you get additional handsets, then anyone in the house can use it
    to make analogue calls and/or SIP calls. You can even make an analogue
    call on one handset and a SIP call on another at the same time.

    They really are the mutts nuts of combined analogue/SIP DECT phones
    right now! I'm pushing these for home workers to use, so their family
    can pickup a handset and dial a number as usual and it goes out over
    their existing analogue line, then the home-worker can dial a number
    followed by a star and it goes over their "work" SIP account (to their
    office VoIP PBX or a service such as Gradwell, voip.co.uk, etc.) .
    An incoming call displays differently (can have different ring tones)
    depending on the line the call comes in on, so work calls can be ignored
    by anyone else in the house.

    Have a look at http://www.provu.co.uk/siemens.html

    Gordon Henderson, Jul 7, 2007
  8. bluebird44

    Tim Guest

    Tim, Jul 7, 2007
  9. bluebird44

    bluebird44 Guest

    Yes, internet sharing on the PC. Either that or connecting the PC and
    VoIP phone with a cheap 5 port switch and using Windows to bridge both
    networks, that way it's not NAT, correct? Also I can use crossover
    cable from the VoIP phone to PC and select both networks in Control
    Panel and select "Bridge Networks"
    Can you recommend a good WiFi access point? One that would create a
    stable wireless bridge with my NetGear WGR614v6.
    I'll check out some DECT phones. Thanks for the tip!
    bluebird44, Jul 8, 2007
  10. I'm not familiar enough with how MS Windows does it's bridging/sharing
    to know if this works as you describe - I know that sort of thing can be
    done in Linux though, so it's not am impossibility it can be done
    I've no experience of anything recent, but this would appear to work,
    even if it has features you may never use:


    That's a netgear unit, so I'd hope it would be OK - the picture on the
    page gives you an idea of it's use.
    Gordon Henderson, Jul 8, 2007
  11. bluebird44

    alexd Guest

    alexd, Jul 9, 2007
  12. bluebird44

    Paul Hayes Guest

    That's what I was thinking of too. Personally though, I'd just run a
    CAT5 cable, it'll probably take less time & be less hassle than trying
    to get windows connection sharing to work and then a VoIP phone double
    NAT-ted. :)

    Paul Hayes, Jul 10, 2007
  13. bluebird44

    bluebird44 Guest

    Got a Grandstream GXP2020 delivered today and working fine with
    crossover cable to PC and network bridging in Windows.

    bluebird44, Jul 12, 2007
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