[Koha] Z39.50 server timing out

[CTS-Programmer 3 (Paul Dokken)]

I am trying some public library Z39.50 sites but am realizing that they are timing out or not responding. 

 I have tried 199.197.115.61:210, z3950.nexpresslibrary.org:5110, sekls.bywatersolutions.com :9998 but they all seem to timeout or give me an error.  I tried http://zserver.spl.org/ into the URL of a browser and I get an error yet I can pull up www.spl.org just fine.  If I try http://lx2.loc.gov:210/ it works fine.  Any ideas why all the others fail except for the Library of Congress?  Our server is located in Papua New Guinea and we use a VSAT internet connection.  

Thanks, Paul

Paul Dokken
Software Developer
SIL PNG Communication and Technology Services
Ukarumpa EHP 444 | Papua New Guinea
cts-prog3 at sil.org.pg
+675-537-3544 x4404 {Telecom}
+675-7081-8666 {Digicel}