Port 9640ProQueSys Flows Service

TCP port 9640 is assigned to ProQueSys Flows Service, whose protocol and common deployment are not publicly documented.

transport: tcp
in transit: cleartext
assignment: official
risk: 1/10
lookups: 0

also known as pqsflows

Technical Details

what runs on :9640

ProQueSys Flows Service is registered on port :9640 over tcp to Sarene Caiazza, assigned April 2010. We don't have a technical write-up for it beyond the IANA registry entry.

In nmap's internet-wide scan data this port is never observed open, so if it's open on your network it's more likely a custom or misconfigured service than the registered one.

find what's listening on :9640

this machine

# linux
sudo ss -tlpn 'sport = :9640'

# macos / bsd
sudo lsof -nP -i :9640

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :9640

another host

nmap -sV -p T:9640 <host>

run it? the handshake, the implementations you meet in the wild and the flags that matter come from the engineers who do.

add technical details

Security Information

exposure of :9640

risk score

1/ 10safe

routine exposure. this port is rarely the way in on its own — keep it patched and logged and move on.

in transit

cleartext

credentials and payloads are readable by anyone on path

assignment

official

registered with iana for this service — scanners fingerprint it by number

reachable over

tcp

every listening transport is another surface to filter at the edge

security overview

no security notes recorded for :9640 yet

known exploits, hardening advice, what a compromise looks like — suggest an edit if you know its exposure.

Record

iana registry entry

port: :9640
service: ProQueSys Flows Service
transport: TCP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: uncategorised
usage: IANA identifies TCP port 9640 as ProQueSys Flows Service and lists Sarene Caiazza as its registrant. No common public implementation or deployment is known, and the port has not appeared open in nmap's scan data.
lookups: 0rank 993
added: 2026-10-16
updated: 2026-10-16
references: IANA service name registry — port 9640

Something wrong?

This record is maintained by the engineers who use port 9640. Every field on it is editable — change what's wrong, say how you know, and a reviewer publishes it, usually within a minute. Last touched 2026-10-16.

01edit any field on a page of its own
02a model checks it for accuracy and spam
03clean and confident goes live immediately

edit this record →back to the registry

Related Ports

browse categories →

ports registered around :9640, by lookups.

port	service	proto	category	risk	views
:9600	Omron FINS Communication	UDP	Network Services	caution	33.2k
:9594	Message System	TCPUDP	—	safe	0
:9666	Zoom Control Panel Game Server Management	TCP	Remote Access	safe	0
:9599	Robix	TCPUDP	—	safe	0
:9695	Content-Centric Networking (CCNx)	TCPUDP	Network Services	safe	0
:9598	Very Simple Control Protocol	TCPUDP	Network Services	risk	0
:9618	HTCondor Collector	TCPUDP	Network Services	caution	0
:9595	Ping Discovery Service	TCPUDP	Network Services	safe	0

risk mix of the 8 listed

safe63%
caution25%
risk13%

0 of 8 encrypted

Port :9640ProQueSys Flows Service

Technical Details

Security Information

Related Ports

Port 9640ProQueSys Flows Service