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Registered 12 years 210 days

Zandweter Thursday, 13 July 2017, 03:00 PM

DECT IP1202 with more handsets than channels, random call drop

Hello evrybody,

I've got 2 customers with 1202 4 channel dect setups and radom calls that get released on connect. Both have more then 4 registered users in reach of the master radio.

I upgraded the last one to a 8 channel solutions wich solved most problems (but the costs are significant). Checking the problems brought me to:

Wiki says:

Known Problems

[edit]incoming calls limited to number of radio/DSP channels

Each incoming call towards a radio base station (IP1202 or IP1202/4) allocated a DSP channel during the alert state.

If more DECT-handsets are subscribed to this base than DSP/radio channels are available, call setup will fail for surplus devices, and result in no audio (just noise).

Example: Call Broadcast to 5 DECT users subscribed in a IP1202/4. One out of these 5 users will alert but without any DSP allocation (random). Answering such a call results in no audio for this user.

When I understand the above correctly I'm playing sort of russian roulette with most DECT setups. It (seems that it) doesn't matter if I make call-broadcast or WQ objects with max 4-8 users if there's more users than channels.

Is this correct? I guess so. Don't you think this should be on the development schedule for a bugfix?

In my opinion a call should alert at all (assigned) handsets, a DSP-channel should only be used for each connected call.

What if I use 8 to 16 handsets in a 'small' room, should I setup 2 dect systems with 2 8-channels radio's? Seems to me that everybody should be well aware of this limitation.

Thanks for your opinion!

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Registered 15 years 189 days

Christoph Künkel (innovaphone) Thursday, 13 July 2017, 03:28 PM

Re: DECT IP1202 with more handsets than channels, random call drop

I think that it is not as bad as you assume. It is simply that you can not have more than 4 calls concurrently and that the call starts when the user is alerted. So if you have 10 handsets it is perfectly OK as long as you do not extraneous parallel calls. If so, you get a busy (I assume). It is like if you have a 2 BRI PSTN gateway with a 10 user PBX behind it. Very common.

If you indeed do call broadcasts or or WQ with more than 4 DECT users as operators, then its not russian roulette - you know in advance that it is not going to work.

For WQs, you want to consider round-robin are multi-level call schemes.

Regards, Christoph

Registered 12 years 210 days

Zandweter Tuesday, 18 July 2017, 03:46 PM

Re: DECT IP1202 with more handsets than channels, random call drop

Hi Christoph, Thanks for your response.

I'm OK with the maxium channels but then it should be a real limit.

Now phones still get alerted and ring, this makes it confusing.

Calls will be disconnected if you take the call and don't have a channel available.

So I've got 1 customer with 4 Manufacturing facilities and 1 main office building.

2 managers work in each location, they change locations once in a while.

When reception doesn't take a call all 8 managers get the call.

Primary group 4, secondary also 4.

What if they have a meeting in the main building, or have lunch break?

Should I hang 2 IP 1202/8 in the lunch of meeting room?

How do I prefer 1 or the other radio?

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Registered 15 years 189 days

Christoph Künkel (innovaphone) Tuesday, 18 July 2017, 03:55 PM

Re: DECT IP1202 with more handsets than channels, random call drop

Kim,

I think there must be something else wrong in your scenario. In my understanding and also according to wiki (which as we all know knows everything)

call setup will fail for surplus devices

That is, in your scenario only 4 of the calls should ultimately alert. I have to admit that I never tried it really so I might be wrong, but alerting the devices without having at least one channel available doesn't make sense to me too.

I suggest that you create a support ticket for this.

Christoph

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Known Problems

[edit]incoming calls limited to number of radio/DSP channels