New to DMR; need a little help understanding some basics

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W0RMT
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Re: New to DMR; need a little help understanding some basics

Post by W0RMT » Sat Jan 04, 2020 1:52 am

VK3KYY wrote:
Fri Jan 03, 2020 7:18 am
kd2lh wrote:
Fri Jan 03, 2020 3:23 am
When the hotspot is operating dynamically, and it receives incoming RF for a given talkgroup, that talkgroup will continue to be forwarded by the VOIP infrastructure to the hotspot through the conversation and not reset until there is no local RF activity on that talkgroup for a timeout period.
On BM with a Simplex Hotspot, the default seems to be an infinite time-out on the TG assigned by transmitting on that TG.

However with a Duplex Hotspot (on BM) there is a definite time-out period, but I don't know what the default value is.

IMHO. The BM dynamically allocated route system on Simplex Hotspots is somewhat buggy, as if you change TG and transmit for a second or two, the dynamic route will appear to have change, and you can sometime even transmit an over of 30 seconds or more, only to find that in the next minute, the dynamically allocated TG reverts back to the TG prior to the TG you are currently on.
This bug/feature causes a lot of confusion on BM.


Even using the BM Selfcare dashboard to remove a dynamically allocated TG, e.g. TG91, its very common for that dynamic route to be reactivated within 30 seconds, and you end up hearing the traffic on TG 91 again.
And it can take multiple attempts of removing the TG91 dynamic route from the Selfcare dashboard before it finally stops routing that traffic to your Hotspot.

Also. On the BM Selfcare dashboard, if you roll over the dynamic route with your mouse, it shows a message saying that transmitting on TG4000 will remove the dynamic route. However this has never worked for me.
On a hotspot connected to BM, the last TG keyed up is set to "auto-static" if no static TGs are set in selfcare or via the BM API in pi-star (for example). That TG will persist if no others are keyed up or if no changes are made via selfcare.

If a second TG is then keyed up, that second TG becomes the auto-static TG, but the previous TG is now dynamic with a 15 minute time out. If traffic comes in over that previous TG, the 15 minute timer is reset, I think. But here is the thing that complicates it that most people do not know: there is a 5 minute "hold-off timer" on the first TG (set by the master server) such that when the second TG is keyed up, the first TG is silenced for 5 minutes, after which time it can receive traffic again. That is the part that confuses most people.

Because of these BM features, I usually advise people with simplex hotspots to *not* set any static TGs and just use the auto-static feature and disconnect. With duplex hotspots however, it makes sense to set static TGs on each TS if you like. Then using digital monitor/promiscuous mode, it is easy to monitor multiple TGs across timeslots. This is something that you cannot easily do on a simplex hotspot.
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Re: New to DMR; need a little help understanding some basics

Post by VK3KYY » Sat Jan 04, 2020 2:31 am

W0RMT wrote:
Sat Jan 04, 2020 1:52 am
If a second TG is then keyed up, that second TG becomes the auto-static TG, but the previous TG is now dynamic with a 15 minute time out. If traffic comes in over that previous TG, the 15 minute timer is reset, I think. But here is the thing that complicates it that most people do not know: there is a 5 minute "hold-off timer" on the first TG (set by the master server) such that when the second TG is keyed up, the first TG is silenced for 5 minutes, after which time it can receive traffic again. That is the part that confuses most people.

Because of these BM features, I usually advise people with simplex hotspots to *not* set any static TGs and just use the auto-static feature and disconnect. With duplex hotspots however, it makes sense to set static TGs on each TS if you like. Then using digital monitor/promiscuous mode, it is easy to monitor multiple TGs across timeslots. This is something that you cannot easily do on a simplex hotspot.
There must be a bug in the 5 minute hold off, because if a second TG is key'ed and becomes the new auto-static the previous / first TG traffic can definitely still come through in the next 30 seconds or more

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W0RMT
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Re: New to DMR; need a little help understanding some basics

Post by W0RMT » Sat Jan 04, 2020 2:41 am

VK3KYY wrote:
Sat Jan 04, 2020 2:31 am
W0RMT wrote:
Sat Jan 04, 2020 1:52 am
If a second TG is then keyed up, that second TG becomes the auto-static TG, but the previous TG is now dynamic with a 15 minute time out. If traffic comes in over that previous TG, the 15 minute timer is reset, I think. But here is the thing that complicates it that most people do not know: there is a 5 minute "hold-off timer" on the first TG (set by the master server) such that when the second TG is keyed up, the first TG is silenced for 5 minutes, after which time it can receive traffic again. That is the part that confuses most people.

Because of these BM features, I usually advise people with simplex hotspots to *not* set any static TGs and just use the auto-static feature and disconnect. With duplex hotspots however, it makes sense to set static TGs on each TS if you like. Then using digital monitor/promiscuous mode, it is easy to monitor multiple TGs across timeslots. This is something that you cannot easily do on a simplex hotspot.
There must be a bug in the 5 minute hold off, because if a second TG is key'ed and becomes the new auto-static the previous / first TG traffic can definitely still come through in the next 30 seconds or more
I wonder if that hold-off timer is different on different BM master servers. I will investigate and let you know what I learn.
Bud W0RMT / VK3BUD
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Re: New to DMR; need a little help understanding some basics

Post by VK3KYY » Sat Jan 04, 2020 3:08 am

W0RMT wrote:
Sat Jan 04, 2020 2:41 am

I wonder if that hold-off timer is different on different BM master servers. I will investigate and let you know what I learn.

OK.

I'm using the BM Australia server

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Re: New to DMR; need a little help understanding some basics

Post by 4I1RAC » Sat Jan 04, 2020 7:41 am

I use BM Australia too. Soon we'll have one for Philippines :)
Angelo, 4I1RAC / N2RAC
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- 51518 crosslinked to DX1ARM 431.600 MHz Fusion repeater, Metro Manila
- 98977 Opengd77
- 515 Philippines

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VK3KYY
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Re: New to DMR; need a little help understanding some basics

Post by VK3KYY » Sat Jan 04, 2020 10:44 am

4I1RAC wrote:
Sat Jan 04, 2020 7:41 am
I use BM Australia too. Soon we'll have one for Philippines :)
I think the server is possibly in Brisbane, so may be closer to the Phillipines than it is to Melbourne ;-)

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Re: New to DMR; need a little help understanding some basics

Post by W0RMT » Sat Jan 04, 2020 2:02 pm

Ok I've got some clarification from Rudy on how this is set up. It seems that US masters are different with the longer hold-off timer. The advice from the BM core team is to have this set for 15 seconds, so perhaps that is how it is set for 5051. Who is the sysop? Maybe we could ask them.
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Re: New to DMR; need a little help understanding some basics

Post by VK3KYY » Sat Jan 04, 2020 9:12 pm

Hold off may already be set to 15 secs.

I think the problem is changing the old TG to dynamic.

For most simplex hotspot users, simply removing the old TG and making the new TG the auto static would be much better, as having 2 TGs active routed to a simplex hotspot will cause problems if one of this is very active.

E.g. if you transmit in TG91 from simplex HS, it’s very hard to get off it.

Even using the Selfcare to remove TG91 is difficult, for some reason it keeps getting added back into the routes, and you keep having to remove it for about 1 minute, before it finally stops being automatically added to the routes

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Re: New to DMR; need a little help understanding some basics

Post by W0RMT » Tue Jan 07, 2020 1:30 am

I agree that on a simplex hotspot, the thing to do is to disconnect the TG (using the BM API tool in pi-star, for example) before keying up the new TG. I suspect that with the short hold-off timer, busy TGs like 91 become re-active before they die out (after 15 minutes) if you're just listening to the new TG after initial key-up.

This is the great benefit of a duplex hotspot. You can use one TS for switching, and the other for monitoring.
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Re: New to DMR; need a little help understanding some basics

Post by VK3KYY » Tue Jan 07, 2020 6:10 am

W0RMT wrote:
Tue Jan 07, 2020 1:30 am
I agree that on a simplex hotspot, the thing to do is to disconnect the TG (using the BM API tool in pi-star, for example) before keying up the new TG. I suspect that with the short hold-off timer, busy TGs like 91 become re-active before they die out (after 15 minutes) if you're just listening to the new TG after initial key-up.

This is the great benefit of a duplex hotspot. You can use one TS for switching, and the other for monitoring.
I couple of guys complained to me about this today, as they mistakenly thought it was the OpenGD77 somehow not filtering on the new TG.
And I keep having to explain, its Brandmeister that is continuing to send the traffic on the old TG, and its nothing to do with the OpenGD77 not filtering it out.

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