CPM's -- c-Bridge Peer Master Managers

The CPM's and QB project has now morphed in to the TGSA, the TalkGroup Server Alliance...more to follow soon, but CPM's are no longer supported and being converted by to CC's


DCI Buffer Bridge CPM List

Mgr TS 1 TS 2 Notes
1 Comm 1  (3777215) Comm 2  (3777216) The original  TRBO-6 TG's
2 TBA TBA Spare
3 Data Bridge TG  (3100) Recommended  (Set-up info)
4 TAC 310   Migrating from TS1 to TS2 soon
5 TBA TBA Spare

While Manager 1 and 3 CPM's are permanent, 2, 4 and 5 will change in the future depending on technical and/or political winds.  CC's are available if your c-Bridge is not able to participate.


DCI Buffer Bridge CPM Participating c-Bridge List

Mgr TG TS 1 / TG TS 2 c-Bridges
1 Comm 1 / Comm 2 IT-DMR, MIT, SF-TRBO, NoCo
2 TBA / TBA Spare for expansion
3 Data / Bridge TG IT-DMR, MIT, NoCo, DMR-IL
4 TAC 310 / TBA IT-DMR, Georgia-DMR, MIT, NoCo, DMR-IL
5 TBA / TBA Spare for expansion

All c-Bridges listed in this table will still receive these TG's even if the the DCI QB c-Bridge drops off this backbone. 


CPM's are a new way to connect c-Bridges to other c-Bridges similar to the Conference Connections or CC's but with far better failover protection if any one c-Bridge were to go offline or in the case here, if the DCI QB were to fall off the Backbone TG server.  The new "X Box" c-Bridges are what truly enable CPM style connections while the backbone is comprised of IPSC-3's and 5's.  CPM's offer several advantages and a few minor disadvantages.  This is fully discussed in the Forum but a nutshell set of pros/con is at the bottom of this page.

There are 5 or 6 key pieces of information that you as a c-Bridge admin need from the upstream c-Bridge:  the c-Bridge DNS, the CPM's UDP port, the authorization key and what exactly is being donated on each timeslot. For example, manager 3 has the Data feed on timeslot 1 and the Bridge talkgroup on timeslot 2.  This CPM is likely the most universal and/or best single to have if you only take one CPM.

CPM's are never to be used to host a repeater nor bind any OTHER TG's to either timeslot except the one or two listed.  They are used only to be a pipe from one c-Bridge to another, exactly the same as a conference connection.  This means that your CPM peer should be bound to your other manager/timeslot groups either by way of PV/Data, Bridge Groups or with Super Groups.  c-Bridges have superior connections and static IP's and typically would seldom have connectivity issues while repeaters tend to have more issues which can destabilize a CPM just as they do on a normal IPSC network.  Additionally, if you connect repeaters or other peers to it, that counts against our manager allotment.  We are already hosting many other bridges and this will unfairly cause us to use up our allotment much sooner so please use your manager bindings to pass down the the services or refer your downstream c-Bridges to DCI for a discussion first on how to best distribute our services.

The services sent downstream are Talkgroups and Data.  The services can appear to you on 1 or both timeslots, they can be 1 or 2 (or more) talkgroups or talkgroups and data.  You may bind to the same timeslot or the opposite timeslot so you maintain flexibility with all your existing managers.  We do not recommend putting data on a busy voice timeslot and that is why our CPM's use a separate timeslot for data as voice trumps data and can timeout data services.

DCI's data services are sent with Private Voice enabled.  If you do not wish to support private Voice, just don't check it in your Data binding for those managers (or all managers) which you do not wish to have access to Private Voice.  Unchecking the PV binding for your CPM peer will disable it for all other bindings so that will enable you to run PV internally on any or all of your other managers without connections to the upstream CPM.

A downstream c-Bridge admin is encouraged to share our resources.  There is no lock or authorization on any Talkgroup or Data service with respect to DCI.  Some talkgroups come with their own restrictions.  The regional talkgroups are a good example of use restrictions.

If you wish to join in, send an Email to DCI and let us know your c-Bridge control center name, your c-Bridge IP, which CPM you would like to have and the peer ID that you will be using on that CPM.  If you have any requests for other TG's, please indicate them and we will consider them also as well the CC's.


CPM Style, the good and the (possible) bad.

  • CPM's don't lose their traffic if any one or more c-Bridges go down (no weak link in the chain syndrome)

  • All other c-Bridges continue to pass services indefinitely no matter the status of 1 or more c-Bridges (parallel path rather than a single serial path or daisy chain)

  • A single CPM can donate 2 or more services (a CC can carry only one service)

  • c-Bridge peers are more robust than the typical repeater (excellent connectivity)

  • IPSC-5's are the best used to host CPM's; no peer allotment considerations

  • CC's have an inherently more robust path between c-Bridges than CC's
  • Small X box c-Bridges have more peer allotment considerations (use CC's)
  • RSSI information does not pass through CPM's (loss rates are OK)

Revised: 09/19/2014 05:43