Mailing List Archive

On Wed, 4 Oct 2023, Chapman, Brad (NBCUniversal) via Outages wrote:
> Are these alerts queued up for later delivery if a device is off-line, out of range, or connected to a Wi-Fi calling network (where these types of cellular signals are not relayed?)
>
> If so, how long are they stored before being purged from the system? 1 hour? 24 hours?

WEA/CMAS are not queued. WEA/CMAS are re-broadcast by carrier towers
multiple times during the valid time (determined by the sender) over
the control channel. In this case, the valid time was 30 minutes.

There is no record in the carrier network which devices received a WEA
broadcast. If you turn your device (off and) on later, during the valid
period, it may receive a tower re-broadcast (or not, radio waves are not
deterministic). Each WEA/CMAS messages have a carrier-specific short
serial number. The mobile device is responsible for detecting duplicate
transmissions (using the short serial number), and not re-alerting for
previous alerts. In annoying situations, if your phone roams between
different carriers, the carrier short serial numbers may not match
causing duplicate alerts.

The alert cache is flushed when you turn you phone off, so it won't detect
old duplicates when turned on again.


SMS Text are different.

SMS Text messages are queued in the carrier network, when you phone comes
back online it makes a point-to-point data request for queued messages.
The carrier keeps a log of SMS Texts, when & where sent, when &
where received
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I had wondered about the delays yesterday. One of my user's phones went off
almost two hours after the window.

Butch Wilson
Dir. of Instructional Technology
Mt. Vernon Township High School
Google Education Trainer (GET)
MCSE/MCSA/Security+
https://about.me/butch_wilson


On Wed, Oct 4, 2023 at 6:10?PM Chapman, Brad (NBCUniversal) via Outages <
outages@outages.org> wrote:

> Are these alerts queued up for later delivery if a device is off-line, out
> of range, or connected to a Wi-Fi calling network (where these types of
> cellular signals are not relayed?)
>
> If so, how long are they stored before being purged from the system? 1
> hour? 24 hours?
>
> -Brad
>
> —Sent from my iPhone
>
> > On Oct 4, 2023, at 2:14 PM, Jay R. Ashworth via Outages <
> outages@outages.org> wrote:
> >
> > ?----- Original Message -----
> >> From: "Jay R. Ashworth via Outages" <outages@outages.org>
> >
> >> I could be unsurprised to find that the carrier VoWIFI proxies missed
> out on
> >> proxying SMS Cell Broadcast, which I gather provides the underlying PHY
> for
> >> CMAS.
> >
> > I have now an authoritative report that no, the carrier WIFI proxies --
> > carrying your voice calls to your carrier over someone else's wifi and
> the
> > Internet, to be clear -- does *not* proxy the cellular control channel
> > necessary to make CMAS/WEA work, and those alerts can be expected NOT to
> > arrive if your phone is on WIFI only or out of all range of ANY
> carrier's
> > towers.
> >
> > The only reports I'm still looking for are ones from people who are sure
> their
> > phone was set to WIFI-only, and was out of range of cell coverage, and
> still
> > got the national test alert, today at 1418EDT.
> >
> > Thanks,
> > -- jra
> > --
> > Jay R. Ashworth Baylink
> jra@baylink.com
> > Designer The Things I Think
> RFC 2100
> > Ashworth & Associates
> https://urldefense.com/v3/__http://www.bcp38.info__;!!PIZeeW5wscynRQ!vPBHEAKWJK1iqBs_wUKJCGXdey6wlJ3jZpvuoSYsSrn7dn5BoXYN-eu04Kb7uXowTvU4wMBjdnrqCfGwinA$
> 2000 Land Rover DII
> > St Petersburg FL USA BCP38: Ask For It By Name! +1 727
> 647 1274
> > _______________________________________________
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> > Outages@outages.org
> >
> https://urldefense.com/v3/__https://puck.nether.net/mailman/listinfo/outages__;!!PIZeeW5wscynRQ!vPBHEAKWJK1iqBs_wUKJCGXdey6wlJ3jZpvuoSYsSrn7dn5BoXYN-eu04Kb7uXowTvU4wMBjdnrqwxtAa-M$
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What my testing experienced based on what I had laying around:
No alert
iphone - no service, wifi
samsung - no service/sim, wifi
samsung - off with service/sim
blackview - no service/sim, wifi

Alert
samsung - no service/sim, no wifi
xperia - with service/sim, wifi
samsung - with service/sim, alerts off
samsung - with service/sim, alerts on

No alerts that were not received at the time were received.
Depending on the os version it either came up as a Presidential Alert or a National Alert.

Brian
________________________________
From: Outages <outages-bounces@outages.org> on behalf of Wilson, Butch via Outages <outages@outages.org>
Sent: Thursday, October 5, 2023 5:21 AM
To: outages@outages.org <outages@outages.org>; Brad.Chapman@nbcuni.com <Brad.Chapman@nbcuni.com>
Subject: Re: [outages] [EXTERNAL] Re: IPAWS/FEMA National Test - VoWIFI

I had wondered about the delays yesterday. One of my user's phones went off almost two hours after the window.

Butch Wilson
Dir. of Instructional Technology
Mt. Vernon Township High School
Google Education Trainer (GET)
MCSE/MCSA/Security+
https://about.me/butch_wilson


On Wed, Oct 4, 2023 at 6:10?PM Chapman, Brad (NBCUniversal) via Outages <outages@outages.org<mailto:outages@outages.org>> wrote:
Are these alerts queued up for later delivery if a device is off-line, out of range, or connected to a Wi-Fi calling network (where these types of cellular signals are not relayed?)

If so, how long are they stored before being purged from the system? 1 hour? 24 hours?

-Brad

—Sent from my iPhone

> On Oct 4, 2023, at 2:14 PM, Jay R. Ashworth via Outages <outages@outages.org<mailto:outages@outages.org>> wrote:
>
> ?----- Original Message -----
>> From: "Jay R. Ashworth via Outages" <outages@outages.org<mailto:outages@outages.org>>
>
>> I could be unsurprised to find that the carrier VoWIFI proxies missed out on
>> proxying SMS Cell Broadcast, which I gather provides the underlying PHY for
>> CMAS.
>
> I have now an authoritative report that no, the carrier WIFI proxies --
> carrying your voice calls to your carrier over someone else's wifi and the
> Internet, to be clear -- does *not* proxy the cellular control channel
> necessary to make CMAS/WEA work, and those alerts can be expected NOT to
> arrive if your phone is on WIFI only or out of all range of ANY carrier's
> towers.
>
> The only reports I'm still looking for are ones from people who are sure their
> phone was set to WIFI-only, and was out of range of cell coverage, and still
> got the national test alert, today at 1418EDT.
>
> Thanks,
> -- jra
> --
> Jay R. Ashworth Baylink jra@baylink.com<mailto:jra@baylink.com>
> Designer The Things I Think RFC 2100
> Ashworth & Associates https://urldefense.com/v3/__http://www.bcp38.info__;!!PIZeeW5wscynRQ!vPBHEAKWJK1iqBs_wUKJCGXdey6wlJ3jZpvuoSYsSrn7dn5BoXYN-eu04Kb7uXowTvU4wMBjdnrqCfGwinA$ 2000 Land Rover DII
> St Petersburg FL USA BCP38: Ask For It By Name! +1 727 647 1274
> _______________________________________________
> Outages mailing list
> Outages@outages.org<mailto:Outages@outages.org>
> https://urldefense.com/v3/__https://puck.nether.net/mailman/listinfo/outages__;!!PIZeeW5wscynRQ!vPBHEAKWJK1iqBs_wUKJCGXdey6wlJ3jZpvuoSYsSrn7dn5BoXYN-eu04Kb7uXowTvU4wMBjdnrqwxtAa-M$
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