Hi,
The link that I have sent you is for the latest version of TNS which is not the one you are looking for. As I said before, login to empower site, go to product fixes section, fix explorer and choose the appropriate product and version (Trading Network Server/7.1.3). This will list the latest version of Fix that is available for 7.1.3 v. Just in case, if you see Fix 21 (for eg), this is the latest fix that is available and its a cumulative fix that includes fix 19 as well.
HTH
Senthil
#B2B-Integration#webMethods#Integration-Server-and-ESB