ELS61 TCP Client local port | Telit Cinterion IoT Developer Community
July 14, 2021 - 12:03pm, 544 views
Hi. When configuring TCP Client with ELS61 I can specify the remote IP and port (AT^SISS "address" parameters). Is there any way to manually set the local port as as well? I noticed that the local TCP port is automatically set to 4097 after each power up and then it's incremented whenever I close and open a TCP session. But is there a way to set it manually?
The reason I'm asking is that if the connection is broken and I reboot the module it will try to use the same port which is already open (hanging) on the server side and it will give me an error (and 30s delay):
^SIS: 0,0,14,"An established connection was aborted, possibly due to a data transmission time-out or protocol error"
You are right that the ports are not assigned randomly. And it is only possible to manually set the local port for TCP listener and UDP.
If it is critical for you I think that it's worth asking your dedicated technical sales person. Maybe it could be possible to find some solution.