TCP/IP socket behavior

asked 2022-08-16 11:42:09 +0000

jorsen gravatar image

updated 2022-08-16 12:57:27 +0000

Jaap gravatar image

Overview: Siemens medical device IP address & port number: WAN:, LAN:, 8850 Laboratory Information System (LIS) IP address & port number:, 7775 Protocol: HL7


  1. Siemens query for test order from LIS via 7775
  2. LIS sends query acknowledgement to Siemens via 7775
  3. LIS sends order down to Siemens via 8850
  4. Siemens acknowledges order to LIS via 8850
  5. Siemens sends completed test result to LIS via 7775
  6. LIS acknowledges test result from Siemens via 7775

note: The LIS application is set to end and re-establish a new socket connection if there is idle time of 20 mins

Problem Statement: Siemens does not receive order acknowledgement and test order from LIS even though Siemens sent order query to LIS via 7775. The LIS vendor said they did not receive our order query, hence they are not able to dispatch the test order to Siemens.

Question: on port 8850, why Siemens keeps resetting the connection [RST, ACK] from 20.27.09 to 00.23.58? on port 7775, why LIS keeps [FIN,ACK] starting from 21.10.22 onwards?

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Dumping a wall of text doesn't work. Adding a link to a publicly accessible file share with a capture file make it so much easier.

Jaap gravatar imageJaap ( 2022-08-16 12:58:33 +0000 )edit

I'm personally having problems mapping the six steps listed to the problem statement...

Notwithstanding, can you confirm that LIS and Siemans are correctly listening on the ports as stated ..?

Are you able to install Pstools from Microsoft on any of these systems ..?

ajaznawaz gravatar imageajaznawaz ( 2022-08-16 22:47:34 +0000 )edit