Article 12847 of vmsnet.networks.tcp-ip.multinet:
>Is there a version of SLiRP or TIA for the DEC VMS/OpenVMS platform? If
>so, where to get it?

It appears the answer is no.

You might check http://marketplace.com/tia/tiahome.html.  From 
http://marketplace.com:70/0/tia/tia.news.txt (last updated December 
1995), I got:

  *** Update on DEC OpenVMS port ***
 
  Development on TIA ports for DEC Alpha and DEC VAX servers will
  continue throughout the remainder of this year and January of
  1996.  As soon as a binary is available for testing, we will
  announce details at the TIA Web site and will post an
  announcement to the TIA VMS mailing list.

  To join this list, send an email to majordomo@marketplace.com
  with a body of

     subscribe tia-vms-beta 

and some old information I have is:

  Date: 17 Jul 1995 20:23:43 GMT
  Message-ID: <3uegsg$bdk@news.arc.nasa.gov>
  Reply-To: wing@tgv.com
  To: Info-VAX@Mvb.Saic.Com

  In article <3ubdba$5or@uwm.edu>, jspinnow@alpha1.csd.uwm.edu (John Stewart Pinnow) writes:
  #
  #Has anyone ported Slirp to OpenVMS that is using NETLIB or runs under
  #UCX.
  #
  #FYI: Slirp is a slip emulator.
  #
  #
  #I would appreciate any information anyone could give me.
  
  Here's some info.
 
  #Path: ames!hookup!swrinde!howland.reston.ans.net!agate!boulder!
  #news.coop.net!village.org!not-for-mail
  #From: imp@marketplace.com
  #Newsgroups: comp.os.vms
  #Subject: Re: SLIP for VMS??
  #Date: 24 Jun 1995 20:07:45 -0600
  #Organization: Cyberspace Development
  #Sender: imp@village.org
  #Message-ID: <3sigdh$a8@rover.village.org>
  #References: <3shel8$2090@usenetw1.news.prodigy.com>
  #
  #In article <3shel8$2090@usenetw1.news.prodigy.com>,
  #Jon Cochran <VWAY75A@prodigy.com> wrote:
  #>My question is do any of the "sliplike" programs (TIA, SLIRP, etc) 
  #>work on VMS?  And if not, are there VMS versions on the way?  Finally 
  #>(whew) does running a "sliplike" program impact the performance of the 
  #>link?
  #
  #TIA is not currently available for VMS, but will be soon.  SLiRP is,
  #AFAIK, not available for VMS at all, and no one is working on it.
  #
  #We've found that TIA's performance is typically the same as a normal
  #SLIP link, and sometimes can be faster (since retransmissions happen
  #between the tia host and the slip "client").  Sometimes it is slightly
  #slower too.
  #
  #We're working on getting TIA 2.0 Beta out the door, and then plan on
  #finishing up the VMS port and making it available hopefully about the
  #same time as 2.0 FCS ships.  The usual software industry disclaimers
  #apply, however.
  #
  #Warner
  #
  #-- 
  #Warner Losh		"VMS Forever"		home: imp@village.org
  #Cyberspace Development, Inc			work: imp@marketplace.com
  #Makers of TIA, The Internet Adapter.		http://marketplace.com/

Hope that helps,
-Dan Wing
 dwing@tgv.com