docker - How to use stun.l.google.com behind a corporate proxy? -

i want configure local copy of

https://github.com/mattermost/mattermost-webrtc/blob/master/vagrant/janus/config/janus.cfg

to enable video calls test purposes in mattermost. 1 part is:

[nat] stun_server = stun.l.google.com stun_port = 19302 

how use stun.l.google.com behind corporate proxy?

i tried

proxytunnel -p corporate-proxy:7123 -d stun.l.google.com:19302 -a 3098 

and replaced first part with

[nat] stun_server = localhost stun_port = 3098 

which results in

$ docker run -it webrtc_blah_2 janus commit: ad2c131617ac989df1a1bbd601272a5e448cbb3e compiled on:  mon jul 24 13:04:22 utc 2017  ---------------------------------------------------   starting meetecho janus (webrtc gateway) v0.2.4 ---------------------------------------------------  checking command line arguments... debug/log level 4 debug/log timestamps disabled debug/log colors enabled adding 'vmnet' ice ignore list... using x.17.0.2 local ip... token based authentication enabled initializing recorder code initializing ice stuff (full mode, ice-tcp candidates disabled, ipv6 support disabled) stun server use: localhost:3098 ice handles watchdog started testing stun server: message of 20 bytes [fatal] [ice.c:janus_ice_set_stun_server:808] no response our stun binding test [fatal] [janus.c:main:3667] invalid stun address localhost:3098 

analogous default config (see last 2 lines):

[fatal] [ice.c:janus_ice_set_stun_server:808] no response our stun binding test [fatal] [janus.c:main:3667] invalid stun address stun.l.google.com:19302 

1.stun , turn both servers definition in respective rfcs can setup on public ips

2.stun server used give public ip of firewall , if configure in firewall , stun binding requests( sbr) result no response there no external server out firewall configured.

3.on supeficial level job of stun server receive sbr source , check ip address transport layer , return same in response plus find 1 port open reach source back.

4.later hole punching done on same port, make open throughout session using stun binding indication.

crux 1 should not configure stun or turn within firewall of no use.