Port 5911Controller Pilot Data Link Communication

SCTP port assignment for Controller Pilot Data Link Communication between aircraft and air traffic controllers.

transport: sctp
in transit: cleartext
assignment: official
risk: 6/10
lookups: 0

also known as cpdlc

Technical Details

what runs on :5911

This assignment identifies CPDLC traffic carried over SCTP. A listener would establish an SCTP association and exchange application messages using SCTP's reliable, message-oriented framing rather than a TCP byte stream; the exact CPDLC profile, stream usage, and surrounding aviation-network protocols depend on the deployment. CPDLC is not an HTTP-style service, and this port should not be assumed to expose a generic Internet API. Encryption and authentication are not guaranteed by SCTP itself and may be provided by the aviation communications architecture or an external protected network.

Security Information

exposure of :5911

risk score

6/ 10risk

treat as sensitive. widely scanned and regularly exploited when reachable — restrict it to known sources.

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

sctp

every listening transport is another surface to filter at the edge

security overview

CPDLC can carry operationally sensitive air-traffic and aircraft-control messages, so an exposed listener should be treated as specialized critical infrastructure. It should normally be restricted to authorized aviation networks; unsolicited Internet access could permit reconnaissance, malformed-message testing, or attempts to interfere with a safety-relevant service. The port's rarity makes random exposure unlikely, but does not make an actual CPDLC endpoint safe to publish publicly.

Record

iana registry entry

port: :5911
service: Controller Pilot Data Link Communication
transport: SCTP
encryption: cleartext
assignment: iana registered
risk: 6/10risk
category: uncategorised
usage: CPDLC is an aviation communications service used to exchange text-like operational messages between aircraft and air traffic control systems. Port 5911 is expected mainly in specialized aviation networks and ground infrastructure, not ordinary enterprise hosts.
lookups: 0rank 993
added: 2026-08-30
updated: 2026-09-22
references: IANA service name registry — port 5911

Something wrong?

This record is maintained by the engineers who use port 5911. 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 2026-09-22.

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 :5911, by lookups.

port	service	proto	category	risk	views
:5938	TeamViewer	TCPUDP	Remote Access	caution	65.0k
:5900	VNC Remote Desktop	TCPUDP	Remote Access	caution	14.2k
:5852	Adeona OpenDHT Client	TCP	Security	caution	9.3k
:5912	Tidal Scheduler Agent	TCP	System	caution	8.5k
:5850	COMIT SE PCR	TCP	Network Services	caution	4.2k
:5859	WHEREHOO	TCPUDP	—	safe	0
:5904	Air-Ground SWIM	TCPUDPSCTP	Network Services	safe	0
:5910	Context Management	SCTP	System	safe	0

risk mix of the 8 listed

safe38%
caution63%

0 of 8 encrypted

Port :5911Controller Pilot Data Link Communication

Technical Details

Security Information

Related Ports

Port 5911Controller Pilot Data Link Communication