Port 3456VAT (Visual Audio Tool)

VAT carries audio for the historical Visual Audio Tool conferencing system, typically using UDP port 3456.

transport: tcp · udp
in transit: cleartext
assignment: official
risk: 2/10
lookups: 0

also known as vat, Van Jacobson audio tool

Technical Details

what runs on :3456

VAT normally carries packetized audio over UDP port 3456, with packets containing a VAT header followed by encoded audio data; deployments commonly used IP multicast for conference distribution. The registry assignment covers both TCP and UDP, but UDP is the expected transport for audio. VAT predates and helped inform later Internet audio and RTP-based systems.

Security Information

exposure of :3456

risk score

2/ 10safe

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

voice and chat averages 3.5 across 152 ports — this one sits 1.5 below.

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

VAT traffic is generally cleartext and provides no modern authentication or confidentiality by default. Exposed listeners could receive spoofed or unwanted audio, be used for traffic amplification or denial of service, and reveal conversations; the obsolete protocol should not normally be exposed to the public Internet.

Record

iana registry entry

port: :3456
service: VAT (Visual Audio Tool)
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 2/10safe
category: Voice and Chat Media
usage: VAT is the historical Visual Audio Tool audio-conferencing protocol developed by Van Jacobson and associated with early MBone multicast conferencing. It is now obsolete and rarely encountered, although legacy multicast or research deployments may still use port 3456.
lookups: 0rank 994
added: 2026-09-10
updated: 2026-09-10
references: IANA service name registry — port 3456

Something wrong?

This record is maintained by the engineers who use port 3456. 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 2026-09-10.

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edit this record →back to the registry

Related Ports

all 152 in voice and chat →

the 8 most looked-up other ports in voice and chat — 152 ports carry that label.

port	service	proto	category	risk	views
:9090	Openfire Admin Console	TCP	Web Services	caution	34.2k
:1513	Garena Gaming	TCPUDP	Gaming	caution	33.1k
:9091	Openfire Admin Console (SSL)	TCPtls	Web Services	caution	28.3k
:2031	Mobrien Chat	TCPUDP	Web Services	caution	27.7k
:1720	H.323 Signaling	TCP	Network Services	caution	26.5k
:6005	Camfrog Chat	TCP	Voice and Chat	caution	25.2k
:3001	Miralix Phone Monitor	TCP	Network Services	caution	21.7k
:9009	Pichat Server	TCPUDP	Network Services	caution	19.7k

risk mix of the 8 listed

caution100%

1 of 8 encrypted

Port :3456VAT (Visual Audio Tool)

Technical Details

Security Information

Related Ports

Port 3456VAT (Visual Audio Tool)