Port 3478TURN (Traversal Using Relays around NAT)

TURN relays traffic for clients that cannot establish a direct connection, commonly supporting WebRTC and VoIP.

transport: tcp · udp
in transit: cleartext
assignment: official
risk: 4/10
lookups: 0

also known as STUN/TURN, RFC 8656

2 other services are registered on port 3478. compare all 3 →

Technical Details

what runs on :3478

TURN uses the STUN message format and request-response transactions: clients authenticate, request an allocation, and send traffic through the server using relayed addresses. Port 3478 is the standard unencrypted TURN/STUN port; clients may connect over UDP or TCP, and TCP is the transport identified by this registry assignment. TURN commonly relays UDP traffic, while TURN over TLS is commonly offered on port 5349. The assignment names TURN over TCP, but the registered transports also include UDP.

Security Information

exposure of :3478

risk score

4/ 10caution

worth attention. how exposed you are depends on configuration — don't leave it reachable from the internet without a reason.

network services averages 2.7 across 1,400 ports — this one sits 1.3 above.

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 · udp

udp is connectionless — source addresses are trivially spoofed and it is a reflection favourite

security overview

TURN is meant to be reachable by clients across the internet, but it should require strong authentication and enforce allocation, bandwidth, and destination limits. An unauthenticated or poorly restricted server can be abused as an open relay, consuming bandwidth or relaying traffic for attackers. TURN on 3478 is not encrypted by default; applications such as WebRTC typically protect media separately with DTLS-SRTP.

Record

iana registry entry

port: :3478
service: TURN (Traversal Using Relays around NAT)
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 4/10caution
category: Network Services Voice and Chat
usage: TURN servers relay media or other traffic when NATs or firewalls prevent two endpoints from connecting directly. Engineers commonly encounter the service in WebRTC and VoIP deployments, where clients use it as a fallback alongside STUN.
lookups: 0rank 993
added: 2026-09-29
updated: 2026-09-29
references: IANA service name registry — port 3478
RFC 8656

Something wrong?

This record is maintained by the engineers who use port 3478. 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 2026-09-29.

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edit this record →back to the registry

Related Ports

all 1,400 in network services →

the 8 most looked-up other ports in network services — 1,400 ports carry that label.

port	service	proto	category	risk	views
:9080	Groove RPC	TCPUDP	Web Services	caution	70.8k
:6543	Jetnet	UDP	Network Services	caution	65.3k
:5938	TeamViewer	TCPUDP	Remote Access	caution	65.0k
:8291	Winbox MikroTik Admin	TCP	Security	caution	62.9k
:3233	WhiskerControl Protocol	TCPUDP	Network Services	caution	61.9k
:3268	Microsoft Global Catalog (GC)	TCPUDP	Security	caution	54.6k
:135	Microsoft EPMAP	TCPUDP	Security	caution	51.9k
:3128	Tatsoft Default HTTP Proxy	TCP	Web Services	caution	46.8k

risk mix of the 8 listed

caution100%

0 of 8 encrypted

Port :3478TURN (Traversal Using Relays around NAT)

Technical Details

Security Information

Related Ports

Port 3478TURN (Traversal Using Relays around NAT)