TCP Socket comm problem

Question

Hi All.

i run windows service , one each on port 8081, 8082 thru 8090. Each port has multiple external incoming connections with data send / receive. Each windows service is  identical c#.net code across all ports.

 

one port, 8083, behaves differently: data sent to external is lost. We can see it on packet sniff on 8083 going out but external does not receive it.

 

if i put same message to same external on any other of the ports, it works.

 

firewall and antivirus is identocal on all ports, so why thsi problem. 8083 has most connections, so am i over utilizing it?

 

thanks