Freepbx rejecting calls before reaching asterisk

Hi All,

Hope everyone is doing well. I’m in a little bit of a pickle. Today our PBX system stopped receiving calls from our provider (Plivo). When doing some digging, CDR doesn’t show any calls, logging into the CLI and putting asterisk in debug mode, I don’t see anything on the screen. However, when I run a packet capture on the PBX system and make a call, I see the following:

488 Not Acceptable Here.

When I look at plivos end, I see the follwoing:

Hangup Cause sdp_not_acceptable_here_by_customer
Hangup Code 4640

I’m the sole administrator for this PBX and I have not changed/updated the system for at least a month (until today after the issue as a troubleshooting step).
I read a few forum posts but nothing has seemed to work.

I should note, calls to and from Twilio are working.

Below is the SIP info:
INVITE sip:[email protected] SIP/2.0
Via: SIP/2.0/UDP 13.52.9.100:5060;branch=z9hG4bKad1.64c9a76d32f6e9dd2259b854810af3a4.0
From: sip:[email protected]:5060;isup-oli=62;tag=gK02288be6
To: sip:[email protected]
Call-ID: [email protected]
CSeq: 16624 INVITE
Max-Forwards: 64
Content-Length: 277
Content-Disposition: session; handling=required
Content-Type: application/sdp
User-Agent: Zentrunk
Accept: application/sdp
Allow: INVITE,ACK,CANCEL,BYE,UPDATE
P-Asserted-Identity: sip:[email protected]
Contact: sip:[email protected]

v=0
o=Sonus_UAC 23680 24208 IN IP4 18.214.109.221
s=SIP Media Capabilities
c=IN IP4 18.214.109.221
t=0 0
m=audio 15690 RTP/AVPF 0 101
a=maxptime:20
a=rtpmap:0 PCMU/8000
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=sendrecv
a=rtcp:15691 IN IP4 18.214.109.221
SIP/2.0 100 Trying
Via: SIP/2.0/UDP 13.52.9.100:5060;rport=5060;received=13.52.9.100;branch=z9hG4bKad1.64c9a76d32f6e9dd2259b854810af3a4.0
Call-ID: [email protected]
From: <sip:[email protected];isup-oli=62>;tag=gK02288be6
To: <sip:[email protected]>
CSeq: 16624 INVITE
Server: FPBX-15.0.16.49(16.9.0)
Content-Length:  0

SIP/2.0 488 Not Acceptable Here
Via: SIP/2.0/UDP 13.52.9.100:5060;rport=5060;received=13.52.9.100;branch=z9hG4bKad1.64c9a76d32f6e9dd2259b854810af3a4.0
Call-ID: [email protected]
From: <sip:[email protected];isup-oli=62>;tag=gK02288be6
To: <sip:[email protected]>;tag=9d596abe-ad7c-4fbd-bf36-a4a7ccf2c1f5
CSeq: 16624 INVITE
Server: FPBX-15.0.16.49(16.9.0)
Content-Length:  0

Any help is greatly appreciated

The SDP contains RTP/AVPF which is not what is normally used. Normally RTP/AVP is used. In the chan_sip module there is a configuration option called “avpf” to enable it. In the chan_pjsip module there is a configuration option named “use_avpf” to enable it. I don’t know where those are in the FreePBX GUI, but that’s likely your underlying problem. It’s possible they changed it on their side somewhere.

Looked around and didn’t see it. I’m guessing I’m going to need to go into the CLI and enable it and see if it works. I’ll let you know.

I added it to the plivo trunk under pjsip.endpoint.conf, restart asterisk using fwconsole restart, made sure it stayed and made a test call, no luck. I am going to remove it tho.

Hi @jcolp,

You were right. It was on the providers side. The issue is now resolved.
I’ve asked for a RCA, hopefully it sheds some light onto what happened.

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