[e2e] Internet Draft and survey on P2P in the presence of NAT

[David P. Reed]

At 01:57 PM 4/9/2003 -0700, Christian Huitema wrote:
>There are implementations available for many platforms, including for
>example VX-Works. The set of spec is published by the UPNP Forum, which
>any company can join free of charge.

FInancially, free of charge, but the agreement places obligations on the 
members.


> > Or maybe I should say that I personally cannot find a simple
>description
> > that enables one to write just the IGD code in my favorite language
> > (Smalltalk) or, for example, Python or Java.
>
>
>The UPNP architecture is available at
>http://www.upnp.org/download/UPnPDA10_20000613.htm.

I read the copyright notice at the top of this "spec".   Funny 
thing.   It's not copyrighted by UPnP.   But instead by a member of 
UPnP.   Another funny thing.  I look at the standards documents and find 
the following words:


THE UPNP FORUM TAKES NO POSITION AS TO WHETHER ANY INTELLECTUAL PROPERTY 
RIGHTS EXIST IN THE STANDARDIZED DCPS. THE STANDARDIZED DCPS ARE PROVIDED 
"AS IS" AND "WITH ALL FAULTS". THE UPNP FORUM MAKES NO WARRANTIES, EXPRESS, 
IMPLIED, STATUTORY, OR OTHERWISE WITH RESPECT TO THE STANDARDIZED DCPS 
INCLUDING BUT NOT LIMITED TO ALL IMPLIED WARRANTIES OF MERCHANTABILITY, 
NON-INFRINGEMENT AND FITNESS FOR A PARTICULAR PURPOSE, OF REASONABLE CARE 
OR WORKMANLIKE EFFORT, OR RESULTS OR OF LACK OF NEGLIGENCE.
© 1999-2001 Microsoft Corporation. All rights Reserved. "

And in any case, Microsoft is the privileged member of the UPnP organization.

Enough said - it's not a standard that one can depend on, and it probably 
contains proprietary traps for the unwary.   It's got the usual 
"commercially reasonable and non-discriminatory" licensing of IPR that 
effectively excludes new startup entrants from competing with the big boys.


>To implement the mapping part of the IGD standard, you need to discover
>the device using SSDP and find the "description port" over which to read
>the description, read the description file using HTTP GET and find the
>"control port" over which to send the command. Once you have done that,
>you can install mappings by sending SOAP commands over HTTP POST, and
>retrieve the SOAP response. Hardly rocket science.

The problem here is that the IGD spec (which is available on the site) 
doesn't define semantics at all.   It defines API syntax, data types, and 
error codes.   In many ways it is a typical Microsoft spec, like the 
original DDE and OLE specs, which gave a couple of simple and incomplete 
examples, and then said that Microsoft Word was the reference 
implementation.   Opaque, binary reference implementations were not very 
useful reference specs.