Would you please tell me more about the following path?
GOIP (outside China) <=> Asterisk (where) <=> VSP (which and where) <=> China/Other
I believe that if the voip packets sent by the GOIP device is not blocked, then either encrypted or plain voip packets will have the same performance.
As for my cases, all SIP clients using ET263 is not encrypted. With the ET263 as the bridge between Mainland China and outside China, the voice quality would not dropped after 15-min conversation.
If the voice over VPN, the voice quality is pretty good. For better performance codec G729 has to be used.
YH |