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

[Christian Huitema]

> >When it comes to NAT traversal, Bryan's survey omits an important
> >reference, the UPNP "Internet Gateway Device" specification,
available
> >at:
> >http://www.upnp.org/standardizeddcps/igd.asp. According to a recent
> >empirical survey, this specification is supported by about 60% of the
> >NAT now sold in the US, and 99% of the NAT sold in Japan.
> 
> The problem with the UPNP IGD is that you cannot easily implement it
for
> non-Microsoft/non-Intel platforms, because it is embedded in a
proprietary
> set of specs.

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.

> 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.

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 UPNP membership agreement determines the extent of patent and
copyright licensing, etc.

-- Christian Huitema