[bars] 911 outage root cause revealed

[Tim K1DC]

Interesting...  If one can take the report at face value they mention 
that the 911 centers could see the phone number of the caller and then 
was able to call them back. Assuming this is a VoIP system, honestly 
what phone system isn't these days, this tells me that the SIP traffic 
was making it through but the audio data was not.  These are typically 
carried on different network ports and require specific firewall rules 
to allow them through.  There is a common problem with VoIP system 
refereed to as 'one-way audio' in which the calls are connected but only 
one of the parties can hear the other.  This situation is almost always 
caused by a misconfiguration of a firewall.  It could also have been a 
defense mechanism whereby some firewalls can block specific ports if it 
sees 'unusual' activity on a port.

If this was the case no amount of redundancy/failover would have helped 
- the system wasn't down, calls were still going through.

73,

T.

On 06/19/2024 22:03, Juan Jiménez wrote:
> https://www.boston25news.com/news/local/massachusetts-officials-reveal-cause-hourslong-911-system-outage/FA22RGI3QBB6FBPWLJMKO7SOFM/
>
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