IPP Mail Archive: Re: IPP> notification methods

IPP Mail Archive: Re: IPP> notification methods

Re: IPP> notification methods

From: Paul Gloger (pgloger@cp10.es.xerox.com)
Date: Fri Aug 11 2000 - 15:58:06 EDT

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    This "argument" between Carl and Peter is a rare, great pleasure, where
    the participants are both knowledgeable and rational and clear enough
    that it's easy to follow and appreciate and even learn from their

    Thanks guys!

    --Paul Gloger

    From: kugler@us.ibm.com
    To: "Zehler, Peter" <Peter.Zehler@usa.xerox.com>
    cc: jkm@underscore.com, ipp@pwg.org
    Date: Fri, 11 Aug 2000 10:56:47 -0600
    Subject: RE: IPP> notification methods


    I once tried to run a server on an ATT Worldnet dial-up account. It just
    didn't work. Their T&Cs say

    Additional Rules of Member Conduct

      1. not use your AT&T WorldNet Service dial-up connection to host a
          dedicated Internet server site.

    It's easy enough for them to prevent you from running a server, simply by
    blocking incoming connections. Whether or not they were actually blocking
    me, or something else was wrong, I don't know. Anyway, there are likely to
    be other problems. For example, (from the DSL Reports knowledge base,

     private ip
     Some DSL (or cable) networks may provide you a private IP address. The
     good news is that probably doesn't change, and is secure. The bad news is
     that it isn't a real IP so nobody on the internet can reach you, although
     you can reach everyone. This is essentially NAT implemented by the
     provider on a grand scale.

     NAT stands for Network Address Translation. NAT is a technique for
     translating one set of IP addresses, often private, to another set, often
     public. Compare NAT to socks -- NAT is often implemented on a router or
     specialized NAT box, although it is equally commonly implemented on a PC,
     running NAT software.

     NAT is a very flexible technique, but in the DSL world you will
     interested (or maybe using) just one implementation: NAT setup to allow a
     single public IP address to be simultaneously reused by multiple internal
     PCs with private IP addresses. To the outside world, you appear to have
     only a single IP, but you actually have many devices 'behind' this IP

     Note, you don't get something for nothing here! With NAT, as with socks,
     incoming connections can be problematic to setup, requiring configuration
     on your NAT capable router, or NAT software, to assign (map) external
     services (web, FTP and so on) through to specific internal machines. Many
     NAT capable devices or software are not sufficiently flexible to cope
     with all requirements and software you may have, and some 'NAT
     unfriendly' protocols break, even if NAT maps them correctly!

    Certainly you can get multiple fixed IP addresses, etc., if you're willing
    to pay for it. The question is: is the marginal utility of INDP
    notifications sufficient to justify the cost of these services.


    "Zehler, Peter" <Peter.Zehler@usa.xerox.com> on 08/11/2000 10:01:30 AM

    To: Carl Kugler/Boulder/IBM@IBMUS, jkm@underscore.com
    cc: ipp@pwg.org
    Subject: RE: IPP> notification methods


    I don't know who your ISP is but mine has no control over a server running
    on my host. They do control the length of my IP lease. In my case the
    lease lasts hours. Certainly enough time for a notification. (Not enough
    time to host a business...they charge for that.)

    I can have a fixed IP address and I can have multiple IP addresses if I so
    desire. The use of INDP assumes programmatic interactions in near real
    time. If I build an application that relies on this it may well impose
    requirements on system/network configurations as well as influence the
    components I buy.

    I see a real need for programmatic as well as end user notification. We
    should be specifying and building enabling technologies. Our role should
    enable policy not to enforce it.


                        Peter Zehler
                        Xerox Architecture Center
                        Email: Peter.Zehler@usa.xerox.com
                        Voice: (716) 265-8755
                        FAX: (716) 265-8792
                        US Mail: Peter Zehler
                                Xerox Corp.
                                800 Phillips Rd.
                                M/S 139-05A
                                Webster NY, 14580-9701


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