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Unread 09-17-2007, 12:12 AM   #12
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Default Test results

Hi Martin,

About your guidelines, I did exactly as you recommended:

So just to re-iterate, if you want to properly receive the ACK message from the other end point, and you are behind a firewall, you must either:

1. Use a protocol like STUN to perform client side NAT handling (Note: STUN is broken in SJPhone and needs to be disabled. Make sure the "Use discovered addresses in SIP" is unchecked. I suspect this is half your problem)
2. Open up your firewall ports and forward to your device
3. Register your device with a proxy that has built-in NAT handling capabilities.
1- For the first option, I tested with X-Lite client with STUN enabled. The result was the same: no success. Incoming call from PSTN was dropped after something like 30 seconds. I captured the messages on the outside interface of the firewall (directly connected on Internet). As you can see on the file, there is no ACK message to the endpoint (X-Lite), though several 200 OK messages were sent.

2- The second option denies me the benefit of mobility, because I can not configure every firewall of every network that I use.

3- For the third option, as you asked I unchecked the "Use discovered addresses in SIP" option on SJ Phone and, consequently, it was used the NAT handling of VoXalot. The result was also the same: no success. I again captured the messages on the firewall outside interface (directly connected on Internet). As you can see on the file, address used at Contact field of 200 OK message is a private address (, because it relies on the NAT handling of VoXalot. In this test the ACK message arrived on the outside interface, but did not reach the endpoint on the private network. The reason, as I have said previously, seems to be because the IP address of the ACK message was different of that of INVITE message.

Just to remind
I also assure you that before the change occurred in July described at everything worked well.
Thank you for your interest in help me. I am willing to make as many tests as necessary to identify the why of this issue.


Attached Files
File Type: txt TShooting-SIP-X-Lite.txt (13.3 KB, 8 views)
File Type: txt TShooting-SIP-SJPhone.txt (15.4 KB, 0 views)
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