I have just provisioned a system in AWS. I used the security group provided in the marketplace but I am having firewall issues.Has anyone worked with this and can give tips?
First tip: explain what firewall issues means, perhaps a screenshot? Second tip, explain your setup. You say you used the security group provided in the market place but does that also mean you use the 3CX provided image or was it a manual install?
Here is a security group template for an AWS Linux 3CX instance:
(Ideally you might want to restrict ssh access further to specific source IPs)
You need to associate that with your instance.
(Instances->Actions->Networking->Change Security Groups)