Couldn't download existing topology

Question

Hello,

I am migrating my skype for business server from 2015 to 2019. So, I have enterprise edition.

My old frontend server name is SFBFE and backend server name SFBDB. The new front end and back end server names are SFB19FE and SFB19DB.

So, I installed new DB server with prerequisites and also installed all prerequisites of new Front End server. Prepared active directory and installed administrative tools. After that, I wanted to download my existing topology from my new front end server but I got the following error.

Previously I used custom port in SQL from 1433 to 1405. When I ran netstat -a in my new front end server, I see that, there is no connection established between my new front end and old back end server. When I ran the command from my new front end server's management shell I also got the same error. Now, please suggest me how to resolve it.

Get-CsManagementStoreReplicationStatus : Could not connect
to SQL server after 3 retries. Reason: A network-related or
instance-specific error occurred while establishing a
connection to SQL Server. The server was not found or was
not accessible. Verify that the instance name is correct and
that SQL Server is configured to allow remote connections.
(provider: Named Pipes Provider, error: 40 - Could not open
a connection to SQL Server)
 Connection String: Data
Source=SFBDB.contoso.com;Initial
Catalog=xds;Integrated Security=True;Application
Name=Microsoft.Rtc.Management;Connection Timeout=60
At line:1 char:1
+ Get-CsManagementStoreReplicationStatus
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [Get-CsManag
   ementStoreReplicationStatus], SqlConnectionException
    + FullyQualifiedErrorId : Microsoft.Rtc.Common.Data.SqlC
   onnectionException,Microsoft.Rtc.Management.Xds.GetOcsMa
  nagementStoreReplicationStatusCmdlet

Answer 1

Previously I used custom port in SQL from 1433 to 1405.

Is SQL Server-Browser service running; that one solve the SQL Server name to the used port?