From: david@westcontrol.removethisbit.com   
      
   alexd wrote:   
   > Meanwhile, at the comp.dcom.sys.cisco Job Justification Hearings, Stefan   
   > Monnier chose the tried and tested strategy of:   
   >   
   >>> IPSEC is very widely used for infrastructure VPNs and is not   
   >>> proprietary.  Cisco interoperates with Checkpoint interoperates with   
   >>> Draytek interoperates with OpenVPN ....... Never found a problem in   
   >>> dozens of cases.   
   >> In which sense do they "interoperate"?   
   >   
   > Which 'they' are you referring to?   
   >   
   >>> OpenVPN is proprietary and will not work with a Draytek router.   
   >> In which sense is OpenVPN proprietary?   
   >   
   > There's only one implementation of the OpenVPN protocol [that I know of -   
   > recompiling for different platforms and writing pretty front ends don't   
   > count as reimplementations in my book]. OpenVPN Solutions LLC [the copyright   
   > holder] are therefore in a position to dictate what the OpenVPN protocol   
   > consists of, for example, changing the default UDP port. Anyone can take the   
   > source and extend it in ways that make it incompatible with OpenVPN, at   
   > which point it's no longer OpenVPN.   
   >   
      
   While it is true (AFAIK) that OpenVPN is the only implementation of the   
   OpenVPN protocol, the protocol is built on SSL - thus the encryption   
   part is very much standard.  The authentication methods are also   
   standard - it's only a certain amount of control information that is   
   OpenVPN specific, and information on that is easily available as is the   
   reference source code (the OpenVPN code).   
      
   As OpenVPN source code is under the GPL, it is certainly true that   
   anyone can take that code and extend it or change it.  It won't be   
   OpenVPN any more (I'm guessing the name is trademarked), and if it is   
   incompatible then it will be of pretty limited use.  However, this means   
   that if the OpenVPN Technologies (the company behind OpenVPN) ever   
   decided to make a new version that is incompatible and closed off, then   
   it would be a simple matter to fork the code and release a "FreeVPN"   
   that remained open and free.  The only reason that no one has done   
   anything like that, or bothered to make other implementations of the   
   protocol, is that the official OpenVPN software and support do a   
   perfectly good job.   
      
   As for your examples of port numbers, OpenVPN has had an IANA official   
   port number since 2004.  And if you want to change it, it's just an   
   entry in the configuration file.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)