DSDPlus Unknown Talkgroups: 0 and -2

[adamfancher]

So I already have a suspicion as to how these are used, hopefully someone can confirm or deny.

The "Unknown" talkgroups denoted by a value of -2 seem to be the "pool" that previously active radio ID's return to when they deregister from a talkgroup and don't join another one on the system.

Also, I see mostly 1677xxxx radio Id's in group 0 and am assuming that 0 denotes an "all call" group.

Can anyone verify if my assumptions are correct?

Thanks in advance

 

[racingfan360]

Is this P25 or DMR/MotoTRBO? In a MotoTRBO system, Talk Group 16777215 is the All Call group.

 

[slicerwizard]

DSDPlus.radios says:

; special group values:
;
; -1: only private calls seen
; -2: group unknown


But I see a lot of group zero, especially on protocols that don't seem to use groups (like D-Star)

 

[cg]

Zero is unaffiliated. 1677xxxx are the random ISSI radios on those random ISSI 65336-65534 groups.

Also, I see mostly 1677xxxx radio Id's in group 0 and am assuming that 0 denotes an "all call" group.

Can anyone verify if my assumptions are correct?

 

[adamfancher]

This is a P25 system.

So it seems that 0 is appropriate for calls that simply do not use a talkgroup at all.

I can see that the radio ID's that I tagged while they were still active in designated talkgroups are present in the -2 group.

My assumption is that either the radio ID's have been decommissioned and returned to the "pool", OR, have simply transferred to another agency on the P25 system that is not on simulcast with the site I am monitoring from (In my case I am monitoring CLMRN in Connecticut and tuned into the State Police Troop H site. This gives me visibility of certain Troops but not others, and our troopers mobile radio affiliations frequently jump from one troop to another). Or both, I suppose.