No reply to our critical packet

Recently our FreePBX server suddenly stopped being able to make outbound calls through our SIP provider. I have confirmed that the port 5060 is still correctly forwarded to the FreePBX server. We also did not make any changes to our trunks our outbound routes. When the call is sent out the sip trunk, it just goes silent, and then gives an error recording after about 15 seconds. The error we get is:

– Called SIP/odn_babytel/14039999999
[2013-06-25 09:59:15] WARNING[2466]: chan_sip.c:4169 retrans_pkt: Retransmission timeout reached on transmission 07c1c98c5630c7d666cba4e1 [email protected]:5060 for seqno 103 (Critical Request) – See
Packet timed out after 31999ms with no response
[2013-06-25 09:59:15] WARNING[2466]: chan_sip.c:4198 retrans_pkt: Hanging up call [email protected]:5060 - no reply to our critical packet (see
== Everyone is busy/congested at this time (1:0/0/1)

We also get this error:
<SIP/301-00000008> Playing ‘number-not-answering.ulaw’ (language ‘en’)
> 0x7fa1d00463f0 – Probation passed - setting RTP source address to
– Executing [[email protected]:4] Congestion(“SIP/301-00000008”, “20”) in new stack
[2013-06-25 09:59:17] WARNING[2599][C-00000004]: channel.c:4816 ast_prod: Prodding channel ‘SIP/301-00000008’ failed

I have checked with the SIP provider, and they seem to think it is an issue on our end. I have e

Running this version of FreePBX: 3.211.63-10

and what does the sip.conf look like?

This would be a firewall/network issue most likely. Usually seen when you have SIP ALG enabled on your firewall

It appears as though the DNSMasq software was causing issues with resolving to the correct DNS entries for BabyTel. We manually put in IP Addresses and I have adjusted the DNS in FreePBX to use our internal DNS server and the issue went away. Has anyone else seen DNSmasq cause issues?

We are seeing a very similar issue that started with “localhost” blacklisting a clients domain and important emails begin failing to arrive at important customers because they were blocked. We changed the hostname of the phone switch as we tracked down “localhost.localdomain” being used to send voicemails by email from FreePBX. The blacklisting stopped, voicemails flowed and then the entire switch went dark after a reboot. DNS and DNSMasq failed. The solution was to hardcode the carriers IP, but that presents problems of its own. SIP ALG is not on. If you populate the DNS section under SYSTEM ADMIN it simply goes blank the next time you reload. You can really break it as well if you save settings under the NETWORK SETTINGS while not changing anything. The issue seems to be the PBXact Utility failing to retain/refresh the settings. We have been able to reproduce this in both 3.211 and 4.211 all loaded from distro. The longer term solution seems to be to manually edit (despite the warnings) the ifcfg.f0 file by adding the DNS entries there manually. The settings are retained after a reload/reboot.