3CX sends internal IP in Contact: Field / No ACK Response

[startelecom]

Provider responds with ACK to 192.168.2.60:5095 which never makes it to the 3CX. Why isn't 3CX using the public (STUN detected) IP in the Contact field?

Note: This is on inbound calls. So 8551234567 is my DID.

X.Y.Z.A = Source IP
X.Y.Z.b = Provider IP



U 2011/03/12 15:05:20.459041 X.Y.Z.A:5095 -> X.Y.Z.b:5094
SIP/2.0 200 OK.
Via: SIP/2.0/UDP X.Y.Z.b:5094;rport=5094;branch=z9hG4bKH254D4rH78j3a.
Contact: <sip:[email protected]:5095>.
To: <sip:8551234567@ X.Y.Z.15:5095>;tag=af65267a.
From: "I ROBOT"<sip:[email protected]>;tag=Z20SBa3mBmt5r.
Call-ID: d4ed42e9-c786-122e-848c-00259010ee66.
CSeq: 9644081 INVITE.
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REGISTER, SUBSCRIBE, NOTIFY, REFER, INFO, MESSAGE.
Content-Type: application/sdp.
Supported: replaces.
User-Agent: 3CXPhoneSystem 9.0.15776.0.
Content-Length: 271.
.
v=0.
o=3cxPS 128731578368 464930209793 IN IP4 192.168.2.60.
s=3cxPS Audio call.
c=IN IP4 192.168.2.60.
t=0 0.
m=audio 7000 RTP/AVP 0 8 101.
c=IN IP4 192.168.2.60.
a=rtpmap:0 PCMU/8000.
a=rtpmap:8 PCMA/8000.
a=rtpmap:101 telephone-event/8000.
a=fmtp:101 0-16.
a=sendrecv.

 

[startelecom]

Re: 3CX sends internal IP in Contact: Field / No ACK Respons

Any further thoughts/ideas?

 

[startelecom]

Re: 3CX sends internal IP in Contact: Field / No ACK Respons

bump?

 

[danhriscanu]

Re: 3CX sends internal IP in Contact: Field / No ACK Respons

Can you upload here a pcap file between your server and the SIP provider? Its easy to follow than a plain text. Also check your settings of your trunk to this Voip provider. Have you followed a 3cx template or you created a generic one? What do you have at outbound proxy?

 

[startelecom]

Re: 3CX sends internal IP in Contact: Field / No ACK Respons

Dan,

Unfortunately that's not possible. I don't feel comfortable posting PCAPs because they include information that I do not want to post like IPs, phone numbers, etc.

I have checked the pcap from the carrier end and the private IPs is included in the contact field and that's where the problem lies as I've indicated from the beginning. The firewall does not do any packet inspection, it's the 3CX box that is incorrectly including the private IP in the contact field, regardless of settings.

Has anyone from 3CX tried to replicate this? It seems like I am doing all the work

If you want me to follow certain steps to try to make it to work, I'd be more than happy to. I used the generic SIP trunk profile. Outbound proxy is blank at the moment.

 

[danhriscanu]

Re: 3CX sends internal IP in Contact: Field / No ACK Respons

Unfortunately I could not replicate your issue but in my opinion its a configuration of sip trunk issue and not a STUN one. In INVITE coming from your provider you should see Contact-URI [your ID]@[IP of provider] instead of "[email protected]:5095".
Try to remake your Voip Provider and in "SIP server hostname or IP" put the IP address of your provider and the port that he specified to you. Outbound proxy hostname and port should be according to your provide specification. Some of them prefer leave it blank and on some of them will be the same as SIP server address.
In account details fill in Authentication ID and External number as told by your SIP provider. On most of them these 2 parameters are the same. Don't check 3 Way Authentication ID!
It should be as simple as that.
Good luck!

 

[startelecom]

Re: 3CX sends internal IP in Contact: Field / No ACK Respons

Dan,

I followed the exact steps you outlined below. I re-created the provider, input their IP in the "SIP Server and hostname or IP" and left the proxy fields blank.

I put dummy data in the external number & authentication ID and left password blank (since the provider doesn't require registration).

Tried to make the call again, and I still see the internal IP in the Contact field. Again, I think this is the root of the problem. I need to be able to populate the external IP in the Contact field and 3CX is not allowing me to do this for some reason.

 

[SY]

Re: 3CX sends internal IP in Contact: Field / No ACK Respons

4 pieces of information should be provided:
1.output of "ipconfig /all" command
2.output of "route print" command
3. description of network topology
4. 3CXPhoneSystem.log and 3CXPhoneSystem.trace.log
a) set debug level of the log
b) restart 3CX PhoneSystem service.
c) wait for 1 minute. Make problematic call.
d) collect logs

If this information cannot be provided then nobody will be able to answer your question

 

[startelecom]

Re: 3CX sends internal IP in Contact: Field / No ACK Respons

Stepan, I've PMed you with requested information.