One inbound number failing

[vintegrity]

Hi all,
I'm running into an issue where one customer is unable to call us. Of course it happens to be an important customer. We haven't noticed any other issues and we are able to call them outbound. We contacted our provider Flowroute and they think the issue is with 3CX but like I said, every other phone call seems to be ok. They provided me with the log below and asked me to check some settings which seem to be right. I don't see the number in blacklists or blocked IP's or anything. If anyone could help it would be appreciated.

Error Provided by Flowroute

“Your phone system is asking the inbound call to authenticate, see the message below we received.:

2019-11-11 13:19:26 -0500 : IP:5060 → IP:5060
SIP/2.0 407 Proxy Authentication Required
Via: SIP/2.0/UDP IP;branch=XXXX
Via: SIP/2.0/UDP IP:5060;branch=XXXX
Via: SIP/2.0/UDP IP;branch=XXXX
Via: SIP/2.0/UDP IP:5060;branch=XXXX
Proxy-Authenticate: Digest nonce=“XXXX”,algorithm=MD5,realm=“3CXPhoneSystem”

Call-ID: @IP
CSeq: 27702 INVITE
User-Agent: 3CXPhoneSystem 15.5.15502.6 (15502)
Content-Length: 0

I don’t if you have access to that but I would make sure authentication is turned on for outbound only, that “Call Source Identification” is not enabled. Because we got that response we pushed this over to a failover. I cannot speak to as to why other calls are not being rejected, is something specific to how this DID is programmed on your 3CX PBX.”

 

[craigreilly]

Is the number listed in the inbound routes? Flowroute sends +1 if I recall - so my inbound rules with them look like this:
*xxxyyyzzzz
xxx being are code
yyyzzzz being the remainder of the number

*4805551212

 

[vintegrity]

No, and I've called from another number in the same area code as the problem number and the call was fine. It seems to be something specific about this individual number but I'm not sure what it could be.

 

[craigreilly]

You answer "NO" - so if it isn't in the inbound rules but is on the same trunk as another number - this would cause the precise issue.

 

[vintegrity]

Hi Craig, I'm sorry I misunderstood. Yes I do have my inbound routes starting with * for both of my phone numbers. The phone number that I'm having a problem getting a call from isn't one of mine...just an outside client. Other incoming numbers from the same area code and identical format are coming in properly.

 

[AWS2P]

Do you have caller number here ?

 

[JohnS_3CX]

Hi @vintegrity

Do you have more than one Flowroute trunk on your system?

Please also read this guide carefully including the remarks section
https://www.3cx.com/docs/usa-sip-trunk-flowroute/

 

[leejor]

To be clear, the problem is one customer (one caller ID) calling one DID, or one customer calling any DID, or the calling the "main" number? Has that been tested?

 

[vintegrity]

Do you have caller number here ?
View attachment 13203

Hi, no nothing in the blacklist.

 

[vintegrity]

Hi @vintegrity

Do you have more than one Flowroute trunk on your system?

Please also read this guide carefully including the remarks section
https://www.3cx.com/docs/usa-sip-trunk-flowroute/

Yes it's just one trunk. I will go through the guide carefully. Thanks.

 

[vintegrity]

To be clear, the problem is one customer (one caller ID) calling one DID, or one customer calling any DID, or the calling the "main" number? Has that been tested?

It's just one customer calling either of our DID's. It's seems to be something specific to that customer phone number. That's why I thought it was Flowroute's problem but they say it's not.

 

[JohnS_3CX]

When the system is asking the inbound call to authenticate it's highly possible the issue is caused by the call source not being identified on that specific call due to the way it was being sent.

So in this case I would compare a capture of a successful call vs the problematic one, and look especially at the called number (i.e the destination, which is your DID). If the system cannot identify the call as belonging to one of its own then it will try to authenticate the incoming call.

 

[Clément Rousseau]

We just had kind of same issue. To be more precise, phone was ringing but when you pick up the phone, the call stop immediatly. We insist on trunk provider and the manage to ask local operator to solve the issue, works fine now.

 

[vintegrity]

I just wanted to update the forum with the solution. The problem was that our trunk number had a * in front of it. So it looked like *8135555555. I switched it to 18135555555 and the calls from the problem number are now coming in properly..