A Port is a number assigned to uniquely identify a connection endpoint and to direct data to a specific service.
What is Port in APN Settings?
The Port field is an optional field allowing you to specify the address of an HTTP proxy to use for all web traffic over this connection. Carriers sometimes use HTTP proxies to modify websites for your device or to improve the speed of common access web pages and resources by caching them. It’s relatively rare for a carrier to require that you use an HTTP Port for your connection.
Port relates to the Proxy field in APN, and if a proxy is being used, you must set Port. There is no default value for this field, and leaving it blank will disable the use of the port. Examples of ports such as 40, 8080, 2083, etc.
Do I need to set Port in APN settings?
Simply, no. As It’s an optional field you don’t need to set a port. But if your carrier service provider recommends you to set a port, then you should add this in the port filed.