Re: Time and Timing Servers

[Mike Hammett]

It sounds like my only option within that facility is BITS. 


I've asked Metaswitch what their requirements are for the TDM clock. 


I will shortly. I could put something up at a friendly customer and pipe it 
back into the CO. 


My current thought is maybe there's a box that can take an off-site input and 
the Frontier BITS input, then output "authoritative" time and timing signals. I 
hate depending on the ILEC (odd, considering I'm in the CO, making them 
responsible for many things), so maybe I can mitigate that risk with an 
external input and some local intelligence. 




- 
Mike Hammett 
Intelligent Computing Solutions 

Midwest Internet Exchange 

The Brothers WISP 

- Original Message -

From: "Forrest Christian (List Account)"  
To: "Mike Hammett"  
Cc: "Majdi S. Abbas" , "nanog list"  
Sent: Thursday, July 11, 2019 11:42:33 PM 
Subject: Re: Time and Timing Servers 



A couple of thoughts here: 


1) I know at some sites there is an external, shared, GPS antenna which is run 
through a distribution amplifier to clients. Worth checking into just in case 
it exists and they forgot to offer it to you. 


2) Do you have any specs on what you need for the TDM clock? If you don't have 
GPS or any other reasonable way to discipline your local clock you could 
conceivably get an accurate freerunning clock and use that. However, if this is 
even possible is going to be based on the accuracy/precision needed for the 
clock. The spec should be something like 10E-11 or something like that, 
possibly with jitter or other specs specified as well. The more accurate, the 
fewer options you will have and the more it will cost. If you only need 10E-6, 
you can do this dirt cheap. If you need 10E-13, you're going to need a Cesium 
clock which will set you back a good five figures (and then some). 


3) Do you have spare, dark fiber or perhaps even a WDM color to somewhere you 
can get GPS? Copper might even work depending on the needs of the switch. The 
thought here is if you have a stable, non-packetized link to somewhere with GPS 
you then have quite a few options for transferring time back to the site. 


I agree with you that NTP time transfer isn't probably accurate enough by 
itself to discipline a clock for TDM... of course depending on the exact needs. 




On Thu, Jul 11, 2019 at 9:25 AM Mike Hammett < na...@ics-il.net > wrote: 




I'll look into Meinberg. 


I recent thread mentioned high-sensitivity receivers often allow GPS to work 
inside. Obviously "inside" has a lot of definitions. 


I will need this facility for the TDM timing signals. It's a central office, 
not a datacenter. 


I don't know that Internet-based NTP would be accurate enough for the timing 
signals that I need. Maybe, maybe not. 







- 
Mike Hammett 
Intelligent Computing Solutions 

Midwest Internet Exchange 

The Brothers WISP 



From: "Majdi S. Abbas" < m...@latt.net > 
To: "Mike Hammett" < na...@ics-il.net > 
Cc: nanog@nanog.org 
Sent: Thursday, July 11, 2019 9:54:26 AM 
Subject: Re: Time and Timing Servers 

On Thu, Jul 11, 2019 at 09:29:46AM -0500, Mike Hammett wrote: 
> There were a lot of NTP threads several weeks ago, but I didn't get an answer 
> to my question amongst all of the other chatter. 
> 
> I'm looking for a device that can receive GPS inside a building without the 
> assistance of an external antenna (Frontier says they no longer allow 
> external antenna), will provide traditional NTP services, and will provide 
> a timing signal that my Metaswitch can work with. 

Unfortunately, L band satellite signals are incredibly weak by 
the time they reach the surface. It's very unlikely this is going to 
work for you (unless it's a wood framed single story building.) 

Generally, I try to ensure that a GNSS antenna is built into the 
contract, to avoid games like this. 

You have two options: 

A) Find a new colocation provider. This may already be on your 
to-do list for other reasons. 

B) Rely on the Internet for timing, using NTP or PTP from 
another location to backfeed the site, and use a box with a good 
stable oscillator to keep time (this can actually be a commercial 
time server with decent holdover characteristics. 

If you're just looking for alternatives to Microsemi, I highly 
recommend talking to the fine folks at Meinberg. 

--msa 






-- 


- Forrest 

Re: Time and Timing Servers

[Brielle Bruns]

On 7/15/2019 1:02 PM, Jay R. Ashworth wrote:

- Original Message -

From: "Majdi S. Abbas" 



Not only are you dependant on Sprint if you go that route
(Verizon is already pulling the plug on CDMA this year.), it was never
any better than +/- 10 ms or so.  You can get that via NTP pointed at
the Internet.


Oh, is *that* why Tracfone's telling it's customers to get new phones by
December...



Wonder if that means VZW is planning on increasing coverage, because 
there are large enough areas of Idaho where I have to turn off LTE on my 
phone in order to get reliable service (or even functional data service).


It gets really old really quick.




--
Brielle Bruns
The Summit Open Source Development Group
http://www.sosdg.org/ http://www.ahbl.org

Re: Time and Timing Servers

[Jay R. Ashworth]

- Original Message -
> From: "Forrest Christian (List Account)" 

> A couple of thoughts here:
> 
> 1) I know at some sites there is an external, shared, GPS antenna which is
> run through a distribution amplifier to clients.   Worth checking into just
> in case it exists and they forgot to offer it to you.

Or, there may be someone else in the facility who *is* "important" enough to
justify being permitted a roof antenna, who could put in a DA and share it 
with you...

Cheers,
-- jra
-- 
Jay R. Ashworth  Baylink   j...@baylink.com
Designer The Things I Think   RFC 2100
Ashworth & Associates   http://www.bcp38.info  2000 Land Rover DII
St Petersburg FL USA  BCP38: Ask For It By Name!   +1 727 647 1274

Re: Time and Timing Servers

[Jay R. Ashworth]

- Original Message -
> From: "Majdi S. Abbas" 

>   Not only are you dependant on Sprint if you go that route
> (Verizon is already pulling the plug on CDMA this year.), it was never
> any better than +/- 10 ms or so.  You can get that via NTP pointed at
> the Internet.

Oh, is *that* why Tracfone's telling it's customers to get new phones by
December...

Cheers,
-- jra
-- 
Jay R. Ashworth  Baylink   j...@baylink.com
Designer The Things I Think   RFC 2100
Ashworth & Associates   http://www.bcp38.info  2000 Land Rover DII
St Petersburg FL USA  BCP38: Ask For It By Name!   +1 727 647 1274

Re: Time and Timing Servers

[Måns Nilsson]

Subject: Re: Time and Timing Servers Date: Thu, Jul 11, 2019 at 09:11:13PM 
+0200 Quoting Karsten Elfenbein (karsten.elfenb...@gmail.com):
> I think you are referencing their chip scale atomic clocks. Which are very
> frequency stable. But still need phase alignment. (Mobile UPS anyone?)

This is not a new problem. 

http://www.leapsecond.com/hpj/v15n11/

Fascinating reading. 
-- 
Måns Nilsson primary/secondary/besserwisser/machina
MN-1334-RIPE   SA0XLR+46 705 989668
YOW!!  Now I understand advanced MICROBIOLOGY and th' new TAX REFORM laws!!


signature.asc
Description: PGP signature

Re: Time and Timing Servers

[Måns Nilsson]

Subject: Re: Time and Timing Servers Date: Thu, Jul 11, 2019 at 10:23:41AM 
-0500 Quoting Mike Hammett (na...@ics-il.net):
> I'll look into Meinberg. 
 
Meinberg are nice people with good hardware. They can do 2048KHz from
GPS and other timing signals, for instance. Then again, some router
vendors do that in boxes you need anyway. As long as the controlling
clock is PTP.
 
> I recent thread mentioned high-sensitivity receivers often allow GPS to work 
> inside. Obviously "inside" has a lot of definitions. 

Indeed. Colo buildings rarely are on the forgiving side of "inside".
In Sweden, most older central offices are built to some degree of bomb
proofness (certainly not safe from direct hit) , with some 10mm of steel
in shutters for all windows, etc. GPS fares not well there. 
 
> I will need this facility for the TDM timing signals. It's a central office, 
> not a datacenter. 

Then you're concerned with frequency and phase to ITU-T G.812, I
suspect. Unless this is your "central central" office, in which case
you need G.811.

> I don't know that Internet-based NTP would be accurate enough for the timing 
> signals that I need. Maybe, maybe not. 

The current trend in today's large frequency/phase consumers, ie. mobile,
is to run PTP over backhaul.  Well behaved NTP _could_ make it, I suspect,
given a good enough clock in the facility, but PTP will definitely work,
assuming you have transmission and hardware capable of doing it. 

"Capable" here, means dark fibre or WDM is required together with
routers and switches that can act as boundaries in PTP sense. If you
rent MPLS or are using plain Internet infrastructure, it becomes a lot
more complicated.

There are frequency/phase transmission solutions (mostly broadcast
related) that easily can transfer your central central cæsium clock
frequency to another site using reasonable-quality IP transport, but
those are neither cheap nor fire-and-forget.

-- 
Måns Nilsson primary/secondary/besserwisser/machina
MN-1334-RIPE   SA0XLR+46 705 989668
I'm gliding over a NUCLEAR WASTE DUMP near ATLANTA, Georgia!!


signature.asc
Description: PGP signature

Re: Time and Timing Servers

[Forrest Christian (List Account)]

A couple of thoughts here:

1) I know at some sites there is an external, shared, GPS antenna which is
run through a distribution amplifier to clients.   Worth checking into just
in case it exists and they forgot to offer it to you.

2) Do you have any specs on what you need for the TDM clock?   If you don't
have GPS or any other reasonable way to discipline your local clock you
could conceivably get an accurate freerunning clock and use that.  However,
if this is even possible is going to be based on the accuracy/precision
needed for the clock.   The spec should be something like 10E-11 or
something like that, possibly with jitter or other specs specified as
well.   The more accurate, the fewer options you will have and the more it
will cost.If you only need 10E-6, you can do this dirt cheap.  If you
need 10E-13, you're going to need a Cesium clock which will set you back a
good five figures (and then some).

3) Do you have spare, dark fiber or perhaps even a WDM color to somewhere
you can get GPS?  Copper might even work depending on the needs of the
switch. The thought here is if you have a stable, non-packetized link to
somewhere with GPS you then have quite a few options for transferring time
back to the site.

I agree with you that NTP time transfer isn't probably accurate enough by
itself to discipline a clock for TDM...  of course depending on the exact
needs.


On Thu, Jul 11, 2019 at 9:25 AM Mike Hammett  wrote:

> I'll look into Meinberg.
>
> I recent thread mentioned high-sensitivity receivers often allow GPS to
> work inside. Obviously "inside" has a lot of definitions.
>
> I will need this facility for the TDM timing signals. It's a central
> office, not a datacenter.
>
> I don't know that Internet-based NTP would be accurate enough for the
> timing signals that I need. Maybe, maybe not.
>
>
>
>
>
> -
> Mike Hammett
> Intelligent Computing Solutions <http://www.ics-il.com/>
> <https://www.facebook.com/ICSIL>
> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb>
> <https://www.linkedin.com/company/intelligent-computing-solutions>
> <https://twitter.com/ICSIL>
> Midwest Internet Exchange <http://www.midwest-ix.com/>
> <https://www.facebook.com/mdwestix>
> <https://www.linkedin.com/company/midwest-internet-exchange>
> <https://twitter.com/mdwestix>
> The Brothers WISP <http://www.thebrotherswisp.com/>
> <https://www.facebook.com/thebrotherswisp>
> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg>
> ----------
> *From: *"Majdi S. Abbas" 
> *To: *"Mike Hammett" 
> *Cc: *nanog@nanog.org
> *Sent: *Thursday, July 11, 2019 9:54:26 AM
> *Subject: *Re: Time and Timing Servers
>
> On Thu, Jul 11, 2019 at 09:29:46AM -0500, Mike Hammett wrote:
> > There were a lot of NTP threads several weeks ago, but I didn't get an
> answer to my question amongst all of the other chatter.
> >
> > I'm looking for a device that can receive GPS inside a building without
> the
> > assistance of an external antenna (Frontier says they no longer allow
> > external antenna), will provide traditional NTP services, and will
> provide
> > a timing signal that my Metaswitch can work with.
>
> Unfortunately, L band satellite signals are incredibly weak by
> the time they reach the surface.  It's very unlikely this is going to
> work for you (unless it's a wood framed single story building.)
>
> Generally, I try to ensure that a GNSS antenna is built into the
> contract, to avoid games like this.
>
> You have two options:
>
> A) Find a new colocation provider.  This may already be on your
> to-do list for other reasons.
>
> B) Rely on the Internet for timing, using NTP or PTP from
> another location to backfeed the site, and use a box with a good
> stable oscillator to keep time (this can actually be a commercial
> time server with decent holdover characteristics.
>
> If you're just looking for alternatives to Microsemi, I highly
> recommend talking to the fine folks at Meinberg.
>
> --msa
>
>

-- 
- Forrest

Re: Time and Timing Servers

[Mike Hammett]

Sure. They have a BITS service. I'm just checking out all of my options. It'd 
be nice to have my own stuff, but that may not be feasible (or possible once 
CDMA goes away). 


Are any of you coloed with Frontier? Have you gotten them to let you install a 
GPS antenna? 





- 
Mike Hammett 
Intelligent Computing Solutions 

Midwest Internet Exchange 

The Brothers WISP 

- Original Message -

From: ke...@contoocook.net 
To: "Karsten Elfenbein" , "Mike Hammett" 
 
Cc: "NANOG"  
Sent: Thursday, July 11, 2019 3:49:35 PM 
Subject: Re: Time and Timing Servers 

I know that many places hosting telecom gear provide "BITS Clock" this is a DS1 
with timing. 
Ask about that, it's an alternative to providing your own. 


- Original Message - 
From: "Karsten Elfenbein"  
To: "Mike Hammett"  
Sent: Thursday, July 11 2019 03:22:01 PM 
Subject: Re: Time and Timing Servers 



I think you are referencing their chip scale atomic clocks. Which are very 
frequency stable. But still need phase alignment. (Mobile UPS anyone?) 


Maybe some peers can provide transparent or boundry clock support. Or someone 
close by in the DC can add an antenna splitter. 


Karsten 


Mike Hammett < na...@ics-il.net > s chrieb am Do., 11. Juli 2019, 16:31: 




There were a lot of NTP threads several weeks ago, but I didn't get an answer 
to my question amongst all of the other chatter. 


I'm looking for a device that can receive GPS inside a building without the 
assistance of an external antenna (Frontier says they no longer allow external 
antenna), will provide traditional NTP services, and will provide a timing 
signal that my Metaswitch can work with. 

I know that MicroSemi via Symmetricom makes these kinds of devices, but I'm 
hoping to look at multiple manufacturers and compare. 




Thanks. 




- 
Mike Hammett 
Intelligent Computing Solutions 

Midwest Internet Exchange 

The Brothers WISP 

Re: Time and Timing Servers

[keith]

I know that many places hosting telecom gear provide "BITS Clock" this is a DS1 with timing.Ask about that, it's an alternative to providing your own.- Original Message -From: "Karsten Elfenbein" To: "Mike Hammett" Sent: Thursday, July 11 2019 03:22:01 PMSubject: Re: Time and Timing ServersI think you are referencing their chip scale atomic clocks. Which are very frequency stable. But still need phase alignment. (Mobile UPS anyone?)Maybe some peers can provide transparent or boundry clock support. Or someone close by in the DC can add an antenna splitter.KarstenMike Hammett  s
 chrieb am Do., 11. Juli 2019, 16:31:There were a lot of NTP threads several weeks ago, but I didn't get an answer to my question amongst all of the other chatter.I'm looking for a device that can receive GPS inside a building without the assistance of an external antenna (Frontier says they no longer allow external antenna), will provide traditional NTP services, and will provide a timing signal that my Metaswitch can work with.I know that MicroSemi via Symmetricom makes these kinds of devices, but I'm hoping to look at multiple manufacturers and compare.Thanks.-Mike HammettIntelligent Computing SolutionsMidwest Internet ExchangeThe Brothers WISP

Re: Time and Timing Servers

[Eric S. Raymond]

Ethan O'Toole :
> > I'm looking for a device that can receive GPS inside a building without
> > the assistance of an external antenna (Frontier says they no longer
> > allow external antenna), will provide traditional NTP services, and will
> > provide a timing signal that my Metaswitch can work with.
> 
> GPS inside a building probably isn't going to work unless you have the
> antenna up against a window.

Concur.  But if you have that, my microserver build on a Raspberry Pi
will do nicely.

https://www.ntpsec.org/white-papers/stratum-1-microserver-howto/

No need for expensive proprietary hardware.
-- 
http://www.catb.org/~esr/;>Eric S. Raymond

Re: Time and Timing Servers

[Karsten Elfenbein]

I think you are referencing their chip scale atomic clocks. Which are very
frequency stable. But still need phase alignment. (Mobile UPS anyone?)

Maybe some peers can provide transparent or boundry clock support. Or
someone close by in the DC can add an antenna splitter.

Karsten

Mike Hammett  schrieb am Do., 11. Juli 2019, 16:31:

> There were a lot of NTP threads several weeks ago, but I didn't get an
> answer to my question amongst all of the other chatter.
>
> I'm looking for a device that can receive GPS inside a building without
> the assistance of an external antenna (Frontier says they no longer allow
> external antenna), will provide traditional NTP services, and will provide
> a timing signal that my Metaswitch can work with.
>
> I know that MicroSemi via Symmetricom makes these kinds of devices, but
> I'm hoping to look at multiple manufacturers and compare.
>
>
> Thanks.
>
>
>
> -
> Mike Hammett
> Intelligent Computing Solutions 
> 
> 
> 
> 
> Midwest Internet Exchange 
> 
> 
> 
> The Brothers WISP 
> 
> 
>

Re: Time and Timing Servers

[James R Cutler]

> On Jul 11, 2019, at 11:23 AM, Mike Hammett  wrote:
> 
> I'll look into Meinberg.
> 
> I recent thread mentioned high-sensitivity receivers often allow GPS to work 
> inside. Obviously "inside" has a lot of definitions.
> 
> I will need this facility for the TDM timing signals. It's a central office, 
> not a datacenter.
> 
> I don't know that Internet-based NTP would be accurate enough for the timing 
> signals that I need. Maybe, maybe not.
> 

My experience with Dave Mills NTP algorithm is that, giving sufficient 
diversity in higher stratum sources, GPS versus Internet sources makes no 
practical difference. This assumes that you are concerned with Time for event 
logging and scheduling and not concerned with frequency and phase for clocking 
data on TDM instances.

If you are worrying about backhoe fade — it’s consequences will most likely 
affect other things more strongly than Time differences.


James R. Cutler
james.cut...@consultant.com
GPG keys: hkps://hkps.pool.sks-keyservers.net

Re: Time and Timing Servers

[Ethan O'Toole]

Isn't a major problem with CDMA-based sources that the networks they depend on 
are getting shut down?


If so, I would imagine there will be timing servers based on the 
replacement cellular technology. Might ask EndRun or one of their 
competitors about it.


- Ethan

Re: Time and Timing Servers

[Mike Hammett]

They can do BITS, but that doesn't solve all of my problems. That said, I may 
have to do many things if I can't find my wonder box. 




- 
Mike Hammett 
Intelligent Computing Solutions 

Midwest Internet Exchange 

The Brothers WISP 

- Original Message -

From: "Chris Boyd"  
To: "NANOG"  
Sent: Thursday, July 11, 2019 10:03:02 AM 
Subject: Re: Time and Timing Servers 



> On Jul 11, 2019, at 10:29 AM, Mike Hammett  wrote: 
> 
> I'm looking for a device that can receive GPS inside a building without the 
> assistance of an external antenna (Frontier says they no longer allow 
> external antenna), will provide traditional NTP services, and will provide a 
> timing signal that my Metaswitch can work with. 

Since it’s a telco facility, maybe they can provide BITS service. Worth asking. 

—Chris 

Re: Time and Timing Servers

[Mike Hammett]

I'll look into Meinberg. 


I recent thread mentioned high-sensitivity receivers often allow GPS to work 
inside. Obviously "inside" has a lot of definitions. 


I will need this facility for the TDM timing signals. It's a central office, 
not a datacenter. 


I don't know that Internet-based NTP would be accurate enough for the timing 
signals that I need. Maybe, maybe not. 







- 
Mike Hammett 
Intelligent Computing Solutions 

Midwest Internet Exchange 

The Brothers WISP 

- Original Message -

From: "Majdi S. Abbas"  
To: "Mike Hammett"  
Cc: nanog@nanog.org 
Sent: Thursday, July 11, 2019 9:54:26 AM 
Subject: Re: Time and Timing Servers 

On Thu, Jul 11, 2019 at 09:29:46AM -0500, Mike Hammett wrote: 
> There were a lot of NTP threads several weeks ago, but I didn't get an answer 
> to my question amongst all of the other chatter. 
> 
> I'm looking for a device that can receive GPS inside a building without the 
> assistance of an external antenna (Frontier says they no longer allow 
> external antenna), will provide traditional NTP services, and will provide 
> a timing signal that my Metaswitch can work with. 

Unfortunately, L band satellite signals are incredibly weak by 
the time they reach the surface. It's very unlikely this is going to 
work for you (unless it's a wood framed single story building.) 

Generally, I try to ensure that a GNSS antenna is built into the 
contract, to avoid games like this. 

You have two options: 

A) Find a new colocation provider. This may already be on your 
to-do list for other reasons. 

B) Rely on the Internet for timing, using NTP or PTP from 
another location to backfeed the site, and use a box with a good 
stable oscillator to keep time (this can actually be a commercial 
time server with decent holdover characteristics. 

If you're just looking for alternatives to Microsemi, I highly 
recommend talking to the fine folks at Meinberg. 

--msa 

Re: Time and Timing Servers

[Warren Kumari]

On Thu, Jul 11, 2019 at 10:30 AM Mike Hammett  wrote:

> There were a lot of NTP threads several weeks ago, but I didn't get an
> answer to my question amongst all of the other chatter.
>
> I'm looking for a device that can receive GPS inside a building without
> the assistance of an external antenna (Frontier says they no longer allow
> external antenna), will provide traditional NTP services, and will provide
> a timing signal that my Metaswitch can work with.
>
> I know that MicroSemi via Symmetricom makes these kinds of devices, but
> I'm hoping to look at multiple manufacturers and compare.
>

I have a Symmetricom S250 with the Rb option -- it has an active antenna;
while it does *technically* work inside buildings it really needs to be
jammed right up against a window to work. In my (top floor in my house)
office it gets no reception unless against a window...

W



>
>
> Thanks.
>
>
>
> -
> Mike Hammett
> Intelligent Computing Solutions 
> 
> 
> 
> 
> Midwest Internet Exchange 
> 
> 
> 
> The Brothers WISP 
> 
> 
>


-- 
I don't think the execution is relevant when it was obviously a bad idea in
the first place.
This is like putting rabid weasels in your pants, and later expressing
regret at having chosen those particular rabid weasels and that pair of
pants.
   ---maf

Re: Time and Timing Servers

[Chris Boyd]

> On Jul 11, 2019, at 10:29 AM, Mike Hammett  wrote:
> 
> I'm looking for a device that can receive GPS inside a building without the 
> assistance of an external antenna (Frontier says they no longer allow 
> external antenna), will provide traditional NTP services, and will provide a 
> timing signal that my Metaswitch can work with.

Since it’s a telco facility, maybe they can provide BITS service. Worth asking.

—Chris

Re: Time and Timing Servers

[Ryan Wilkins]

Yes, expect CDMA cellular to disappear before too long.

Verizon is shutting down their CDMA network at the end of this year.

Sprint announced in February 2019 that it is no longer activating CDMA-only 
devices starting May 1 2019.  No sunset date has been announced yet but suffice 
it to say the ball is in motion to sunset their CDMA network.

Any of the regional carriers that run CDMA networks are likely to follow suit 
in short order.

Ryan Wilkins

> On Jul 11, 2019, at 10:50 AM, Mike Hammett  wrote:
> 
> Isn't a major problem with CDMA-based sources that the networks they depend 
> on are getting shut down?
> 
> 
> 
> -
> Mike Hammett
> Intelligent Computing Solutions <http://www.ics-il.com/>
>  <https://www.facebook.com/ICSIL> 
> <https://plus.google.com/+IntelligentComputingSolutionsDeKalb> 
> <https://www.linkedin.com/company/intelligent-computing-solutions> 
> <https://twitter.com/ICSIL>
> Midwest Internet Exchange <http://www.midwest-ix.com/>
>  <https://www.facebook.com/mdwestix> 
> <https://www.linkedin.com/company/midwest-internet-exchange> 
> <https://twitter.com/mdwestix>
> The Brothers WISP <http://www.thebrotherswisp.com/>
>  <https://www.facebook.com/thebrotherswisp> 
> <https://www.youtube.com/channel/UCXSdfxQv7SpoRQYNyLwntZg>
> From: "Ethan O'Toole" 
> To: "Mike Hammett" 
> Cc: nanog@nanog.org
> Sent: Thursday, July 11, 2019 9:46:24 AM
> Subject: Re: Time and Timing Servers
> 
> > I'm looking for a device that can receive GPS inside a building without 
> > the assistance of an external antenna (Frontier says they no longer 
> > allow external antenna), will provide traditional NTP services, and will 
> > provide a timing signal that my Metaswitch can work with.
> 
> GPS inside a building probably isn't going to work unless you have the 
> antenna up against a window.
> 
> Look at CDMA NTP Servers like the EndRun Sonoma. They use the cellular 
> network which requires accurate timing and has good building penetration.
> 
>  - Ethan O'Toole

Re: Time and Timing Servers

[Majdi S. Abbas]

On Thu, Jul 11, 2019 at 09:50:48AM -0500, Mike Hammett wrote:
> Isn't a major problem with CDMA-based sources that the networks 
> they depend on are getting shut down? 

Domestically, yes.

Not only are you dependant on Sprint if you go that route
(Verizon is already pulling the plug on CDMA this year.), it was never
any better than +/- 10 ms or so.  You can get that via NTP pointed at
the Internet.

At best, all you were doing with CDMA was relying on a cell 
site's GPS receiver and holdover characteristics -- which were totally
opaque to you.  At least you can monitor NTP. 

--msa

Re: Time and Timing Servers

[Majdi S. Abbas]

On Thu, Jul 11, 2019 at 09:29:46AM -0500, Mike Hammett wrote:
> There were a lot of NTP threads several weeks ago, but I didn't get an answer 
> to my question amongst all of the other chatter. 
> 
> I'm looking for a device that can receive GPS inside a building without the 
> assistance of an external antenna (Frontier says they no longer allow 
> external antenna), will provide traditional NTP services, and will provide 
> a timing signal that my Metaswitch can work with. 

Unfortunately, L band satellite signals are incredibly weak by
the time they reach the surface.  It's very unlikely this is going to
work for you (unless it's a wood framed single story building.)

Generally, I try to ensure that a GNSS antenna is built into the
contract, to avoid games like this.

You have two options:

A) Find a new colocation provider.  This may already be on your
to-do list for other reasons.

B) Rely on the Internet for timing, using NTP or PTP from 
another location to backfeed the site, and use a box with a good
stable oscillator to keep time (this can actually be a commercial
time server with decent holdover characteristics.

If you're just looking for alternatives to Microsemi, I highly
recommend talking to the fine folks at Meinberg.

--msa

Re: Time and Timing Servers

[Mike Hammett]

Isn't a major problem with CDMA-based sources that the networks they depend on 
are getting shut down? 




- 
Mike Hammett 
Intelligent Computing Solutions 

Midwest Internet Exchange 

The Brothers WISP 

- Original Message -

From: "Ethan O'Toole"  
To: "Mike Hammett"  
Cc: nanog@nanog.org 
Sent: Thursday, July 11, 2019 9:46:24 AM 
Subject: Re: Time and Timing Servers 

> I'm looking for a device that can receive GPS inside a building without 
> the assistance of an external antenna (Frontier says they no longer 
> allow external antenna), will provide traditional NTP services, and will 
> provide a timing signal that my Metaswitch can work with. 

GPS inside a building probably isn't going to work unless you have the 
antenna up against a window. 

Look at CDMA NTP Servers like the EndRun Sonoma. They use the cellular 
network which requires accurate timing and has good building penetration. 

- Ethan O'Toole 

Re: Time and Timing Servers

[Ethan O'Toole]

I'm looking for a device that can receive GPS inside a building without 
the assistance of an external antenna (Frontier says they no longer 
allow external antenna), will provide traditional NTP services, and will 
provide a timing signal that my Metaswitch can work with.


GPS inside a building probably isn't going to work unless you have the 
antenna up against a window.


Look at CDMA NTP Servers like the EndRun Sonoma. They use the cellular 
network which requires accurate timing and has good building penetration.


- Ethan O'Toole