Port 2123GTP Control Plane

3GPP GTP control-plane signaling used between cellular core-network elements.

transport: tcp · udp
in transit: cleartext
assignment: official
risk: 8/10
lookups: 0

also known as GTPv1-C, GTPv2-C

Technical Details

what runs on :2123

GTP-C is a 3GPP signaling protocol normally carried over UDP port 2123; the registry also lists TCP. Messages use GTP headers containing version, message type, length, and transaction or tunnel identifiers, with request/response exchanges such as Echo, Create Session, Modify Bearer, and Delete Session. GTP-U user traffic is normally separate on UDP 2152, while GTP' charging traffic uses UDP or TCP 3386.

Security Information

exposure of :2123

risk score

8/ 10risk

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

network services averages 3.6 across 713 ports — this one sits 4.4 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

GTP-C is generally cleartext and assumes it is exchanged only within a trusted mobile-operator core or protected interconnect. It should not be exposed to the public internet: reachable endpoints may be subject to message spoofing, malformed-packet attacks, unauthorized session manipulation, and denial of service, depending on vendor validation and core-network controls.

Record

iana registry entry

port: :2123
service: GTP Control Plane
transport: TCPUDP
encryption: cleartext
assignment: iana registered
risk: 8/10risk
category: Network Services Mobile
usage: GTP Control Plane carries signaling between mobile-network elements such as SGSNs, GGSNs, MMEs, SGWs, PGWs, and serving gateways. It is commonly seen in 2G/3G packet-core deployments as GTPv1-C and in 4G EPC networks as GTPv2-C.
lookups: 0rank 994
added: 2026-08-24
updated: 2026-08-24
references: IANA service name registry — port 2123

Something wrong?

This record is maintained by the engineers who use port 2123. 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 2026-08-24.

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

all 713 in network services →

the 8 most looked-up other ports in network services — 713 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 :2123GTP Control Plane

Technical Details

Security Information

Related Ports

Port 2123GTP Control Plane