Can a Sprint High Speed Data Card provide a unique MAC Address to a VOIP Server?

Posted on 2007-10-10
Last Modified: 2010-03-25
Can a Sprint High Speed Data Card provide a unique MAC Address to a VOIP Server?
Question by:ccarkeek
    LVL 39

    Expert Comment

    If you are communicating using an ethernet adapter then you allready have a globaly unique
    MAC address. As that is a requirement for delivering ethernet adapters.


    Author Comment

    We have an NEC VOIP Server, which differentiates VOIP phones through the MAC address of the phone.  We are trying to deploy NEC Dterm SP30 Softphones on mobile laptops.  The loptops use Sprint PX-500 High Speed Data Cards for internet access.  Each time the server registers a softphone to the intended extension for that user, it replaces the previous users softphone/extension capability, so that only one mobile Sprint connected softphone is allowed by the server.  We found that each Sprint connection has the same Physical (MAC) appearance to the server because they all present themselves, as the same Physical (MAC) address, regardless of the card number.  We hope there is some way to make the Sprint data cards appear as unique entities to the server, by making their physical (MAC) identity unique.
    LVL 39

    Expert Comment

    The MAC address is an Ethernet/Wireless/... adress.
    A network based on 'layer-2' switches is a network that uses MAC-addresses to deliver packets to
    the various systems. (this also called a switched or bridged network).

    Then you have layer-3 (up until recently only routing, now also switched). In these networks MAC addresses are uses to address a LAN, the router sits between LAN's. Assume a LAN A and B, with a Router in between
    (Pa a system on LANa Ra interface of router on LAN A Rb and Pb likewise on LAN B).

    To transmit a packet from Pa to Pb, first Pa finds out the MAC address of Ra and send's it the packet (Ra is the [default-]gateway to other systems) R finds out the MAC address of Pb and forward the packet with Rb as its sources address. Now Pb known where the answer should go etc.....

    So if you pass through a router the routers address is used as the originating MAC address
    (Every interface has it's own MAC address.) My Guess is there is a router between then laptop's and the VOIP server.
    Is it possible to build a bridged wireless environment or remove router from the path between your systems and the VOIP server.
    Are you sure the VOIP server can't differentiate on thing else then MAC-addresses? Because it that's the only way then you need one big LAN to access your VOIP services.

    As there is a trend in networking to move to Layer-3 switching the basic address will become an IPv4 and later an IPv6  address.

    Author Comment

    When we do ipconfig /all on the laptops, they show a unique physical address for the ethernet connection, and a unique physical address for the wireless connection, but they all show the same physical address for the PX-500 Sprint data cards.  The NEC VOIP Server confirms that the non-unique physical address of the PX-500 cards is considered the MAC address by the NEC VOIP Server.  Since there is no difference in physical address among all the PX-500s, the server sees only one laptop identity, and that causes the problem.  Why NEC doesn't support a true ID/Password logon is a mystery.  Why Sprint doesn't supply a unique address, for each card, might have something to do with hoping that VOIP will go away.  It all makes for a bad situation for mobile users, who are stuck with an NEC phone system.
    LVL 39

    Accepted Solution

    I agree with you, External equipment cannot supply you a MAC address, it is more or less fixed in hardware.
    That said, many ethernet card support modification of the MAC address by issuing special command to them.
    Maybe such a tool will exist also for the PX-500? If not and the NEC VOIP server cannot handle a different scheme for authorisation then you're basicaly stuck. (BTW, a MAC address for authorisation is not exactly safe).

    As most dataconnections on cellular networks are considered to be point to point the central hub should use a different scheme (Phone number f.e., Sim card no etc) to differentiate betweeen sessions.

    Write Comment

    Please enter a first name

    Please enter a last name

    We will never share this with anyone.

    Featured Post

    What Security Threats Are You Missing?

    Enhance your security with threat intelligence from the web. Get trending threat insights on hackers, exploits, and suspicious IP addresses delivered to your inbox with our free Cyber Daily.

    Suggested Solutions

    Title # Comments Views Activity
    Tracking Data 2 61
    How do I unlock my iPhone? 6 78
    historical call history 6 51
    Looking for "Downloads" on an Android 3 23
    Having problems with your LG G3? Whether the front camera doesn’t work, the display doesn’t turn on, or your phone just doesn’t seem to be charging, you’ll be able to troubleshoot the issue with this step-by-step guide.  Phone doesn’t Charge It ta…
    As the title indicates, I have done this before. It chills me everytime I update the OS on my phone, ( because one time I did this and I essentially had a bricked …
    Need more eyes on your posted question? Go ahead and follow the quick steps in this video to learn how to Request Attention to your question. *Log into your Experts Exchange account *Find the question you want to Request Attention for *Go to the e…
    Illustrator's Shape Builder tool will let you combine shapes visually and interactively. This video shows the Mac version, but the tool works the same way in Windows. To follow along with this video, you can draw your own shapes or download the file…

    779 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    12 Experts available now in Live!

    Get 1:1 Help Now