Connecting 7960 IP phones directly to PC

Discussion in 'Cisco' started by Pete Calvert, Dec 1, 2003.

  1. Pete Calvert

    Pete Calvert Guest


    I am trying to find out if the following is actually possible to do.

    I have a small experimental network of PCs running Linux with network
    configuration controlled dynamically via software running on a Windows
    machine which alters the configuration of a 2950 switch to create VLANs etc
    which in essence break and make links between nodes. There is also
    software running on these nodes which simulate different network effects
    such as restricting bandwidth, packet loss, delay etc. What I would like
    to do is to connect some 7960 phones to the nodes and then send calls
    across the network to see how calls are affected by different network

    Is it actually possible to do this? If so how? Would it need something
    like a SIP server running on each node or maybe CCM running on the Windows

    I'm not too familiar with VoIP networks so forgive me if this is trivial.

    Many thanks for any help.


    Pete Calvert
    Mobile Secure Information Networks
    (remove NOSPAM to reply)
    Pete Calvert, Dec 1, 2003
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  2. Pete Calvert

    Thomas Voigt Guest


    You will need a CCM running because the ip phones are totally dumb
    without one.
    Thomas Voigt, Dec 2, 2003
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  3. Pete Calvert

    Blaz Zupan Guest

    That is not true. If you put SIP software on them, you can place calls from
    phone to phone just fine.
    Blaz Zupan, Dec 2, 2003
  4. Pete Calvert

    chris Guest

    If you go SIP, there is plenty of open-source gatekeeper software for
    chris, Dec 3, 2003
  5. Pete Calvert

    Pete Calvert Guest

    So if I use SIP how would the network be setup. Would it be a case of
    connecting the phone to a PC (via a hub/switch) then setting up the phone
    to talk to the SIP server. Would the SIP server take care of routing to
    other phones? How would the phone know what numbers could be called?

    I've been reading a bit about SIP and it seems to be able to do what I
    want, but I don't have practical experience in actually setting up VoIP
    networks so I don't know how this will work.

    Thanks for the help so far.

    Pete Calvert, Dec 3, 2003
  6. Pete Calvert

    Blaz Zupan Guest

    If you only have two phones, connect both to the same hub/switch and then set
    one as the SIP server for the other and vice versa. This should work for calling
    from one phone to the other. With the Cisco ATA 186, you can dial a number like
    "123**192*168*0*1" to call IP address, not sure if this is possible
    with the 7960. Otherwise, for a simple test, you can install Asterisk on Linux
    ( Asterisk is a softswitch which supports H.323, SIP,
    MGCP and I believe even the Cisco proprietary Skinny protocol.
    Blaz Zupan, Dec 3, 2003
  7. Pete Calvert

    Pete Calvert Guest

    What I actually want to do is connect the IP phones to PCs so the VoIP
    traffic is sent through the PC so that our bespoke piece of software can
    apply different network effects. Having thought about the problem a bit
    more I see there are some other issues:

    1) If the CCM is placed on the control machine in the network then all the
    call setup traffic would have to go by a seperate LAN to the VoIP traffic,
    which I don't think is possible with the 7960 phones.
    2) I'm don't think it will be possible to use SIP on the phones as the same
    phones will be used in a different network controlled with a CCM, which
    would mean loading and reloading of firmware which I think would be too big
    a task for the customer.
    3) The nodes within the network are running Linux so AFAIK there is no way
    of running CCM on them.

    There are however DTEs which connect to the Linux nodes, so I think a
    possible solution would be to connect the phones to the DTEs and then run
    CCM on each of the DTEs.

    A few questions about this solution:

    a) How does the licensing for CCM work? Would I be able to buy one 100
    user licence and be able to run CCM on all the DTEs, or would it require a
    licence for each DTE?
    b) In this solution would it be simple to get the CCMs on the DTEs to talk
    to each other.
    c) Does anyone have a feel for the amount of overhead traffic there would
    be between the CCMs


    Pete Calvert, Dec 4, 2003
  8. Pete Calvert

    totojepast Guest

    So if I use SIP how would the network be setup. Would it be a case of
    Is the Skinny protocol derived from SIP?
    totojepast, Dec 5, 2003
  9. Pete Calvert

    Blaz Zupan Guest

    No idea. You might want to ask on the Asterisk mailing lists (see, they should know as they implemented a Skinny channel driver
    for Asterisk :)
    Blaz Zupan, Dec 5, 2003
  10. Pete Calvert

    Andre Beck Guest

    How do the Linux boxes do this? Are they routers or are they bridges?
    They could be both, it merely depends on what your traffic manipulation
    solution can deal with.
    Why not just establish a routed network with a CCM somewhere? As long
    as you can reach any IP in this network, the phones will work and find
    their CCM (just configure them manually).
    Andre Beck, Dec 7, 2003
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