Port 5586AT&T Mobile-Terminated SMS

AT&T's registered TCP port for sending mobile-terminated SMS to a handset application without displaying the message to the user.

inMobile

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

also known as att-mt-sms

Technical Details

what runs on :5586

AT&T Mobile-Terminated SMS is registered on port :5586 over tcp to ATT, assigned August 2014. 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 :5586

this machine

# linux
sudo ss -tlpn 'sport = :5586'

# macos / bsd
sudo lsof -nP -i :5586

# windows (then: tasklist /FI "PID eq <pid>")
netstat -ano | findstr :5586

another host

nmap -sV -p T:5586 <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 :5586

risk score

1/ 10safe

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

mobile averages 2.0 across 88 ports — this one sits 1.0 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

every listening transport is another surface to filter at the edge

security overview

no security notes recorded for :5586 yet

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

Record

iana registry entry

port: :5586
service: AT&T Mobile-Terminated SMS
transport: TCP
encryption: cleartext
assignment: iana registered
risk: 1/10safe
category: Mobile
usage: The IANA assignment describes AT&T using this port to send mobile-terminated SMS to a specific handset port so the message is not visible to the client. It is a private assignment, not a commonly encountered public TCP listener.
lookups: 0rank 993
added: 2026-10-08
updated: 2026-10-08
references: IANA service name registry — port 5586

Something wrong?

This record is maintained by the engineers who use port 5586. 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 2026-10-08.

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 88 in mobile →

the 8 most looked-up other ports in mobile — 88 ports carry that label.

port	service	proto	category	risk	views
:8882	Atlasz Secure App Server	TCP	Web Services	caution	66.9k
:2082	Infowave Mobility	TCP	Network Services	caution	17.7k
:3386	GTP (GPRS Tunneling Protocol)	TCPUDP	Network Services	caution	16.7k
:7401	RTPS DDS Traffic	TCPUDP	Network Services	safe	14.7k
:2948	WAP Push MMS	TCPUDP	Network Services	safe	11.7k
:5222	XMPP Client Connection	TCP	Network Services	caution	11.7k
:3006	Miralix SMS Connector	TCP	Mobile	caution	11.3k
:2949	WAP Pushsecure MMS	TCPUDP	Cloud	safe	10.4k

risk mix of the 8 listed

safe38%
caution63%

0 of 8 encrypted

Port :5586AT&T Mobile-Terminated SMS

Technical Details

Security Information

Related Ports

Port 5586AT&T Mobile-Terminated SMS