# WHATPORT(1533)

## NAME

port 1533 — Sametime Community Server (virtual-places) — The IM and presence port for Lotus/IBM/HCL Sametime Community Servers.

Protocol: TCP  
IANA registry

## DESCRIPTION

IANA registers 1533 as "virtual-places" to Avshalom Houri, whose Ubique work became IBM's Sametime, so the registration and the real use are the same lineage under different names. A Sametime Community Server listens on TCP 1533 for the proprietary Sametime community protocol carrying login, presence, buddy lists, and instant messages; the client's "Direct connection using TCP/IP" preference targets exactly this port. It shows up on scans of Domino/Sametime infrastructure inside enterprises that still run HCL's collaboration stack.

## EXPOSURE

**Do not expose.** This is an authenticated corporate IM plane carrying credentials and message content over a proprietary protocol — publish it through a Sametime proxy/edge tier or a VPN, not by exposing the community server itself.

## CHECK

```sh
nc -vz -w 3 TARGET 1533
```

## SEE ALSO

- docs — [IBM Sametime 9.0.0 — Connecting a client through a direct connection over TCP/IP (default port 1533)](https://www.ibm.com/docs/en/sametime/9.0.0?topic=server-connecting-client-through-direct-connection-over-tcpip) (ibm.com)
- docs — [HCL Sametime — Managing client connections](https://help.hcl-software.com/sametime/9.0.1/admin/admin_st_manage_client_connect.html) (help.hcl-software.com)
- iana — [IANA port registry — 1533](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=1533) (iana.org)

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HTML: <https://whatport.net/1533/> · JSON: <https://whatport.net/1533.json> · full dataset: <https://whatport.net/ports.json>