Fixed - No PBX response for external incoming call


I have a vitual phone number (from United World Telecom) which fowards to sip:[email protected] (My external IP).

I tried to allow inbound call from my provider. But when i call the phone number i get no answer, no tone, no message… nothing happens. After 30 seconds (around) the call is drop.

First of all i show you all the info:


Fresh installed FreePBX distro Stable-1.813.210.58 Release Date-06/08/12 64Bits

Global Settings:

UDP Bindaddress:
TCP SIP Bindaddress: Disabled
TLS SIP Bindaddress: Disabled
Videosupport: No
Textsupport: No
Ignore SDP sess. ver.: No
AutoCreate Peer: No
Match Auth Username: No
Allow unknown access: Yes
Allow subscriptions: Yes
Allow overlap dialing: Yes
Allow promisc. redir: No
Enable call counters: No
SIP domain support: No
Realm. auth: No
Our auth realm asterisk
Use domains as realms: No
Call to non-local dom.: Yes
URI user is phone no: No
Always auth rejects: Yes
Direct RTP setup: No
User Agent: FPBX-2.10.1(
SDP Session Name: Asterisk PBX
SDP Owner Name: root
Reg. context: (not set)
Regexten on Qualify: No
Legacy userfield parse: No
Caller ID: Unknown
From: Domain:
Record SIP history: Off
Call Events: Off
Auth. Failure Events: Off
T.38 support: No
T.38 EC mode: Unknown
T.38 MaxDtgrm: -1
SIP realtime: Disabled
Qualify Freq : 60000 ms
Q.850 Reason header: No

Network QoS Settings:

IP ToS RTP audio: EF
IP ToS RTP video: AF41
IP ToS RTP text: CS0
802.1p CoS SIP: 4
802.1p CoS RTP audio: 5
802.1p CoS RTP video: 6
802.1p CoS RTP text: 5
Jitterbuffer enabled: No

Network Settings:

SIP address remapping: Enabled using externaddr
Externaddr: (MI EXTERNAL IP)
Externrefresh: 10

Global Signalling Settings:

Codecs: 0xe (gsm|ulaw|alaw)
Codec Order: ulaw:20,alaw:20,gsm:20
Relax DTMF: No
RFC2833 Compensation: No
Symmetric RTP: Yes
Compact SIP headers: No
RTP Keepalive: 0 (Disabled)
RTP Timeout: 30
RTP Hold Timeout: 300
MWI NOTIFY mime type: application/simple-message-summary
DNS SRV lookup: No
Pedantic SIP support: Yes
Reg. min duration 60 secs
Reg. max duration: 3600 secs
Reg. default duration: 120 secs
Outbound reg. timeout: 20 secs
Outbound reg. attempts: 0
Notify ringing state: Yes
Include CID: No
Notify hold state: Yes
SIP Transfer mode: open
Max Call Bitrate: 384 kbps
Auto-Framing: No
Outb. proxy:
Session Timers: Accept
Session Refresher: uas
Session Expires: 1800 secs
Session Min-SE: 90 secs
Timer T1: 500
Timer T1 minimum: 100
Timer B: 32000
No premature media: Yes
Max forwards: 70

Default Settings:

Allowed transports: UDP
Outbound transport: UDP
Context: from-sip-external
Force rport: Yes
DTMF: rfc2833
Qualify: 0
Use ClientCode: No
Progress inband: Never
MOH Interpret: default
MOH Suggest:
Voice Mail Extension: *97

Allow SIP Guests: YES Allow Anonymous Inbound SIP Calls? YES

Thes extension 180 is assigned to the provider for registration.
I configured the extension: 180 as follow (extracted from Mysql sip table):

keyword data
account 180
allow ulaw&alaw&gsm
callerid device <180>
canreinvite yes
context from-internal
dial SIP/180
dtmfmode rfc2833
encryption no
host dynamic
mailbox [email protected]
nat yes
port 5060
qualify yes
qualifyfreq 30
secret A_PASS
sendrpid no
transport udp
trustrpid no
type friend

I tried with 2 Incoming routes,
the first incoming route - for ext 180

Did Number: 180
all by default
set destination: Extension 115

mi personal extension is 115, i am logged and i can do internal calls to other extensions
When incoming route works i will change the destination to Ring Group.

I read a post about to config a trunk with the provider IP to avoid anonymous calls, but as i cannot do outbound calls with this provider i was not sure if i did a correct config. As this option did not work, i deleted the trunk and i am at same point again.

My network context is:

Public fixed IP.

Wifi router with foward ports:
10000-20000 My Internal PBX ip ALL
5060-5082 My Internal PBX ip ALL
5090 My Internal PBX ip ALL
As i got many problems, i changed UDP ports to UPD + TCP, for testing purposes

I cleaned rules and temporaly disconnected IPTABLES service at PBX.

I can connect from outside the office and connect an extension for internal calls, i supose NAT and port foward is running.

Asterisk console VERBOSE

When is go into console and increase VERBOSE level (i tested above 20) or if i enable sip debug:
I only see other SIP accounts.
But i did not see any information about extension 180 or provider IP

I run TCPDUMP and processed it with WireShark.
After filtering data, I only got a repeated inbound packet from IP (i receive this packet only while i try to call to virtual number).
But there is no packet in response from local PBX.
This is the packet:

97 16.095806 IPv4 1514 Fragmented IP protocol (proto=UDP 0x11, off=0, ID=b8d5)
INVITE sip:[email protected]_EXTERNAL_IP SIP/2.0
Via: SIP/2.0/UDP;rport;branch=z9hG4bK5703cd6bed1-a50f1836-b7a72436
Via: SIP/2.0/UDP;x-route-tag=“tgrp:VOIP_DD”;branch=z9hG4bK3D8B3EF;rport=49666
From: sip:[email protected];tag=290F6038-1874
To: sip:[email protected]_EXTERNAL_IP
Date: Thu, 19 Jul 2012 06:34:53 GMT
Call-ID: [email protected]
Supported: 100rel,timer
Min-SE: 1800
Cisco-Guid: 2936419891-3500282337-2318008340-1766112416
User-Agent: Cisco-SIPGateway/IOS-12.x
CSeq: 101 INVITE
Max-Forwards: 69
Remote-Party-ID: sip:[email protected];party=calling;screen=yes;privacy=off
Timestamp: 1342679693
Contact: sip:[email protected]
Call-Info: sip:;method="NOTIFY;Event=telephone-event;Duration=2000"
Expires: 180
Allow-Events: telephone-event
Record-Route: sip:;lr
Content-Type: application/sdp
Content-Length: 487

o=CiscoSystemsSIP-GW-UserAgent 5461 7675 IN IP4
s=SIP Call
c=IN IP4
t=0 0
m=audio 63286 RTP/AVP 18 4 3 98 99 2 0 8 101 19
c=IN IP4
a=rtpmap:18 G729/8000
a=fmtp:18 annexb=yes
a=rtpmap:4 G723/8000
a=fmtp:4 annexa=yes
a=rtpmap:3 GSM/8000
a=rtpmap:98 G726-16/8000
a=rtpmap:99 G726-24/8000
a=rtpmap:2 G726-32/8000
a=rtpmap:0 PCMU/8000
a=rtpmap:8 PCM

I spent a week trying to figure the problem. I will appreciate any help.


ISP provider updated the firmware of cable modem.
I tested my config at other ISP and it is working fine.