Arm Mbed OS support forum

Can multiple sockets be opened at the same time viathe same physical network interface?


I assume it is OK to connect to multiple WebSocket servers at the same time via Ethernet Phy. How about other network interface such as ESP8266 or cellular modules that connects to MCU via UART? I tend to think not, but am not sure. Can someone confirm this?

Thanks in advance.

I tested with EC25 cellular module; it seems two simultaneous WebSocket connections work totally fine. I guess as long as bandwidth usage doesn’t saturate either underlining UART baud rate or up link, everything should be OK.

Hello Li,

I’m also not use but tend to agree with you. Although one can set the maximum number of open sockets using the options in mbed-os/connectivity/lwipstack/mbed_lib.json (the default is 4) the final performance depends on the capability of the used hardware.

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Thanks for the pointer. I was not aware there is an option for max number of open sockets. Once TLS/SSL is involved, I guess the limiting factor is really RAM usage.