Multiple Cloud Connector appliances within a single PSTN site Requirements RRS feed

  • Question

  • For multiple Cloud Connector Editions within a single PSTN _ ie 2 x CCEs

    Do they have to be on the same subnet? What communication (if any) is required between them?

    We have two very well connected sites.

    So could we have one CCE in site 1 and the other in site 2? (They would be on different vlans\subnets). The thinking is if we loose one site users would still be able to make and receive calls without having to perform effectively DR.  

    I can see that "If you are deploying High Availability (HA) for the site, make sure you run the cmdlet to set the Site Directory to the same location on each host server within the site." So it looks like they must be able to access the same file share

    Thanks for any comments

    Out of interest I see each CCE has effectively its own Domain Controller. Is there any relationship between the DC for CCE 1 and that of CCE 2?

    Thanks for any advice.


    Thursday, October 19, 2017 1:47 PM

All replies

  • Hi AlistairK,

    In my opinion, it should be in the same subnet. As you said, if you deploy HA for the site, it needs to access the same file share.

    For Multiple Cloud Connector appliances within a single PSTN site, for scalability and high availability purposes, you can choose to have multiple Cloud Connector Editions within a single PSTN site as shown in the following diagram

    Here is a document for your reference https://technet.microsoft.com/en-us/library/mt605227.aspx


    Alice Wang

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    • Edited by Alice-Wang Friday, October 20, 2017 2:30 AM
    Friday, October 20, 2017 2:19 AM
  • Thanks for the reply.

    I suspect having the devices on the same subnet is all that has been tested and by inference all that is supported as you say.

    Still interested to know what interaction there is between the devices.

    Technically I suspect it could work (though supportability is the key issue).

    • If traffic between the two is not blocked by firewall I suspect high probability it will work.
    • If there is a firewall then I suspect the probability of it working drops but I don't know enough on how it works to comment

    I believe I will have to lab this up but that will take a lot of time and cost for the certificates and given that CCE life is limited ...




    Friday, October 20, 2017 8:03 AM
  • My thinking is as yours, looking forward to your lab results.
    Tuesday, October 31, 2017 6:22 AM
  • You may refer to this official CCE topology from Microsoft.


    One deploys multi-CCE-appliances in a single site for "scalability and high availability".

    To answer your questions:

    1. If there is no firewall blockage, it will definitely work.

    2. Even if there is a Firewall blockage between the two CCE appliances, assumed you open required firewall for each CCE to connect to the Office365 and PSTN gateway, they will still work separately. 

    2.1 You just lost "scalability and high availability" if there is a FW blockage between the two CCE appliances in a Site.

    Tuesday, October 31, 2017 3:14 PM
  • hi,

    we faced the issue when calls to PSTN didn't work and found that in HA setup each Edge server can talk to each Mediation server.

    Based that Edge internal network doesn't have the default GW configured and having two CCEs in different subnets, the communication between Edge 01 and Mediation 02 for example, was failing.

    There is no strict rule on Microsoft sites to have CCEs in HA mode installed in the same subnet unless  cannot find them.

    The workaround was to add a persistent route to each Edge server pointing to Mediation server in different subnet.

    • Proposed as answer by Bouslov Wednesday, May 2, 2018 3:49 PM
    Wednesday, May 2, 2018 3:28 PM