CC3220SF: Port number used by the router

Hi Sneha,

CC32xx know only source port (own port) and destination port (port of server). If router (NAT) do some kind of port translation, CC32xx is not able determine this.

I am not sure, if I answered your question. Because your question does not technically make much sense. What is a port number used by router? Router does not use any port. Router is just a device between two subnets, which forwards packets according router tables.

Jan

Hi Jan,

Just to make my question clear

When I create a socket using sl_Socket(), I get a value between 0 and 15 on the cc32xx device.

However on the server, I see the device connecting with port 1234 or 53456 etc.

Where does this come from ?

Thanks!

Hi Jan,

Is it possible to access the API that generates the source port for CC3220 ?

Is it possible that the same port number is generated after a power cycle of the CC3220 ?

Hi,

If you want to use same exact source port number you can call bind before connect like this. But generally this is a not best way and it is straight forward way to went into troubles with routing.

Jan

Hi Jan,

I do not want to use the same port, but I would like to know if the simplelink api would create the same port number after a power cycle ?

Thanks!

Hi,

I don't what is exact strategy of assigning source ports for TCP connection. But you can test this at your side without any issue.

Jan

Hi Jan,

Can you point me to the source code in the SDK that is used for assigning source ports for a TCP connection ?

Thank you!

Hi,

I am not aware of such example in SDK, because this is unusual think. But I provided you example how can bind before connect look like at my previous answer.

Jan

Hi!

I am not looking for the example. I would like to know the source code while where the tcp port handling for the sockets are implemented in the sdk

Thanks!

Hi,

This is implemented inside NWP, and from this reason you cannot found this in SDK source code.

Jan

Got it, Thanks!