my situation similar
starting in Nov2018, all sip phones in Guangdong can register to hk elastix
and hear the voice but sip phones registered to same elastix cannot hear their voice!
change port, change public ip of elastix and those sip phones did not work...!
it seem sip connection blocked!
however, voice through iax is ok but quality is not that good as a phone call pass thro 2 elastix servers now.
Ching, any idea, i dont see any solution for your vmess on Google!
I thought only me experienced this problem. Anyway, we have to do something which can hide our signalling and voice traffic across network broader. Since I was busy with using vmess (one of V2Ray protocols) to surf HK websites, I guess we can use similar method to get ride of this annoyed voip blocking problem. I need to speed some time to explore this possibility. Besides vmess, we may use other methods, for instance ss-tunneling method.
Your IAX method is a short-termed solution, we need a more secure method to overcome this issue.
As per your message, are you using two Elastix boxes, one in Guangzhou and the other in HK. Both of them are linked using the IAX protocol right?
Unencrypted VOIP packets can very easily be detected. Skype is detected based on the initial connection and communication between two peers based on that initial connection is then disturbed or blocked.
Pure encrypted tunnels like VPNs carrying voice or Skype traffic cannot be detected by DPI devices.
Finally I got a solution for this issue. The initial problem came from desktop Siemens DECT IP phone. There is no encryption when connected to the HK Asterisk server. The traffic goes through the local ISP. I thought local IPS has done something in blocking VoIP traffic.
In this morning, I use mobile phone with the built-in data plan to make phone calls to one of my friends in Hong Kong and found the same problem (phone dropped after a few minutes talk). Based on my past experience, I have to run the VoIP over a VPN/proxy tunnels. Then I closed the VoiP app and started BifrostV to connect the remote HK V2Ray node to form a secured tunnel. I switched on VoIP app again. I can able to talk with my friend for more than an hour without any interruption.
After the call, I checked with my BifrostV data flow information. I indicated my VoiP app make phone call via proxy (the V2Ray server in HK) via the port 443.
For the case of the second post, you have to established a link built by V2Ray between your Guangzhou and Hong Kong office. Connect your phone call via the port 443 through the umbrella of V2Ray tunnel.
exactly the same issue for me!
they detect the SIP signal and block you or mess up/delay your packet!!!
reboot the router cause a lot of issues in domain (ddns) update
Finally I got a solution for this issue. The initial problem came from desktop Siemens DECT IP phone ...
角色 發表於 2019-2-10 15:07
I try to digest it
but it is a bit technical for me
i think i have to read and experiment a lot before I come back to you and report!
hope i figure out what to do
a thousand thanks for your advice
it is very kind of you to share your findings!!!!
Based on my findings, using V2Ray's dokodemo (port forwarding method) should help you in resolving the VoIP issue when when you switch to use the single-port aix protocol [1,2].
In case you need to establish site-to-site, you may consider to use the OpenVPN method [1].
發表於 2019-2-8 19:25
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