# WHATPORT(1755)

## NAME

port 1755 — MMS (Microsoft Media Server) — The old mms:// streaming protocol from Windows Media Services — retired hardware and retired software.

Protocol: TCP  
IANA registry

## DESCRIPTION

MMS is Microsoft's proprietary streaming protocol for Windows Media, documented as [MS-MMSP], using TCP 1755 for the control and data stream (with a UDP variant on the same number for the media path). Microsoft deprecated it in favour of RTSP with Windows Media Services 9 Series in 2003 and dropped server support in the Windows Server 2008 release, keeping mms:// URLs only as a rollover hint that made players try RTSP first. Anything still answering on 1755 is a streaming server old enough to predate that change, or an embedded encoder shipped with one.

## EXPOSURE

**Do not expose.** Reaching this port means running server software that has been out of support for well over a decade and receives no security fixes — the exposure problem is the vintage of the code, not the protocol's design.

## CHECK

```sh
nc -vz -w 3 TARGET 1755
```

## SEE ALSO

- spec — [[MS-MMSP]: Microsoft Media Server Protocol — Transport (TCP/UDP 1755)](https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-mmsp/b03203af-1072-4ed0-a619-2e560a789928) (learn.microsoft.com)
- iana — [IANA port registry — 1755](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=1755) (iana.org)

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HTML: <https://whatport.net/1755/> · JSON: <https://whatport.net/1755.json> · full dataset: <https://whatport.net/ports.json>