Some cloud-mss customers ask us this problem because the standard SIP port (UDP 5060) is blocked by their ISP in their countries.
So we upgrade cloud-MSS to support several UDP ports: 5060, 6060 and 8080. In the cloud management interface, you can select one of them in “Basic call / System information”. Please refer to following figure for more details:
If you select a UDP port which is not standard 5060, you must change configurations in SIP phones/clients. Below figure is a demo configuration of xlite since we change the port to 8080.