TCP Entry Point

This entry point accepts TCP traffic from an Air for Cellular device and forwards the individual packet (strictly one TCP segment) to the cloud service.

Entry Point

Your device should be configured to send data to: tcp://



The maximum transmission data size per request is based on the TCP fragment size. While the TCP specification allows a maximum of 65,536 bytes per packet, the actual maximum is determined by the MTU of the network path. In most cases, the maximum packet size is approximately 1500 bytes, with the maximum payload slightly less.


Since TCP has no request and response mechanism like HTTP, Funnel will return a TCP packet to the device containing the HTTP response code and message received from the cloud service. The TCP packet message will use the following format: ${http-status-code} ${http-response-body}

When data has been successfully sent to the cloud service, Funnel will simply return a TCP packet containing the following body:


If the Funnel Content type has been set to JSON and the data contains invalid JSON, Funnel will return a TCP packet with the FIN flag, containing the following body:

400 Invalid JSON is send to funnel.


Establish a TCP session with Funnel:

nc -v 23080
>found 0 associations
>found 1 connections:
>     1:    flags=82<CONNECTED,PREFERRED>
>  outif en0
>  src port 51053
>  dst port 23080
>  rank info not available
>  TCP aux info available
>Connection to port 23080 [tcp/*] succeeded!

Send valid JSON:

>(request) {"key":"value"}
>(response) 200

Send invalid JSON:

>(request) bad text
>(response) 400 Invalid JSON is send to funnel.