503 Error: How to specify ext IP in SDP?

[Sopock]

Hi!
Consider scenario when provider has assigned static private IP(class A) for voice interface. In this case, 3CX will use own local IP in SDP(192.*)
No effect on Use this IP Address option.
Now I wonder, maybe MSEXTERNALADDRESS should be present in 3cxmediaserver.ini?

Thanks.

 

[andreaschr]

Hi Sopock ,

Edit the Voip Provider go to Options and enable "Put Public IP in SIP VIA Header".
Enter the ip you want there.

 

[Sopock]

Hi andreaschr,
unfortunately still same error. I should point out there are no errors when using softphone in which external IP can be set.

You can probably test this case even in virtual V14 which can act as provider. Only trouble could be wrong kind of virtual NAT... :idea:

 Private                       NAT                         Private
     Network 1                      │                          Network 2
                                    │
                                    │
    ┌────-───┐                      │                         ┌-───────┐
    │        ├─────────────────────-┼───────────────-──-──────┤        │
    │        │                      │                         │        │
    │  V14   │                      │                         │   V15  │
    │        │                      │                         │        │
    │        │                      │                         │        │
    └──────-─┘                      │                         └──────-─┘
                                    │
                                    │

 

[Sopock]

Local SDP vs Remote SDP

Any progress on this simple and longstanding issue?

 

[NickD_3CX]

After investigating about this scenario (example screenshots below), the 3CX software in the SDP will always put the NIC IP:

To be more specific, ONLY in the scenario where in the Provider Settings:
- The Providers Server IP is an IP in the LAN ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16)
- You have NOT specified an Outbound Proxy

Then regardless if you have specified a specific reply IP address in the Provider Settings, it will be disregarded and the NIC IP will be used.

To further clarify, in the above example screenshot, even if in the Provider Settings an put "Use this IP" and set 192.168.9.172, when making calls, the 3CX Server in the SDP will send 192.168.2.250.

 

[Sopock]

Thank you for investigation.

It seems there is no change if I set same name for Outbound Proxy. Maybe I should mention that ATA/IAD will register to 3CX only by tcp using Wan1 IP. That could explain lack of Outbound Proxy/STUN?

 

[NickD_3CX]

I don't think that should make a difference. Generally if you have a Proxy and it has a LAN IP, typically it would be on your network so it sending the NIC IP would not be a problem in that scenario. Sorry I didn't clarify that better.