Install google voice (optional) on your smart mobile phone, ( Android)  even if you are not in the USA .
It serves a minimal function ( like making Calls tp  USA / Canada for free )- for those of you who are not in the USA .
 
(See screen shots on page 8 )
 
And very few relevant to those who want to GV out side of the USA / Canada.  This work well  Singapore , perhaps elsewhere too
Thank you Google for being flexible enough. ( for that Option to work around) which now allows for google voice to be installed beyond the borders of USA .
 * The US forwarding number meets the partial requirement and with that, it can be installed anywhere.

 Port Forward your routers to help Hangouts 

 
   And  any of you who have  routers at home or workplaces and have some control over it and know how to .. should perhaps  Port forward some UDP and TCP ports.
 
 Visit the page ( for details)  https://support.google.com/a/answer/1279090?hl=en
 
Below is the  screenshot/ edited for essentials .
 
Optimize hanout
 
 
 
 
 
 Visit the page ( for details)  https://support.google.com/a/answer/1279090?hl=en
 
 
And google port forwarding for all else and specific your own routers.
 
 
Trust me it takes  several attempts to get it all tweaked up . 
 
Some tricks works on some routers .. some don't ..      Follow some the tricks done by those specifically using the router makes models that you have .
 
Always save the router configuration after getting it right or many times along the way ... so that it can be instantly updated , if you reset your routers .
That would be 1 thing that you will not regret after a router hard reset .   Dumping in the known configuration will then be snappy.
 
 
 
 
  • Bug your telco to maintain good data speeds .
  •   IDA ( in our context in singapore) is a bit deaf to these realities. They have become nothing but proxies to the telco and seat warmers.
At least  1 Mb/s up and down ( both ways upstream and downsteam) is a basic that these telcos have to meet. 
 
  • 512  Kbs each minimum (at any moment )  for upstream as well as downsteam to support some of the better Audio quality VOIP codecs.  
 
They claim the upper max in their ads and never really even meet 1 Mb/s on an average .
Singtel is perhaps the worst. 

 
 
................................................
 
 
 

 
 Port trigger / Port forwarding is done slightly different on all the routers .
 
 
I have used and  experience in port forwarding with Make / Models like
 
Linksys  - several types
( not for GV / Hangout in those days) but more for games   
 
2 Wire ,
And GV and others over the last few years ( 2010 and onwards)
TP Link ,
 
  Asus RT-AC56U ( now )
 
 
Visit the manufacturers site and learn it .