The following table lists the network ports that are required for various features of Windows Live Messenger 8.1 on a Windows Vista-based computer.
| Feature | Port that is used |
| Sign in to the Messenger service | TCP 80, 443, 1863 |
| Network Detection | TCP 7001
UDP 9, 7001 |
| Audio
| TCP 80, 443, 1863
TCP/UDP 30000 - 65535 |
| Audio (Legacy) * | UDP 5004 – 65535 |
| Webcam and Video Conversations | TCP 80
TCP/UDP 5000 - 65535 |
| File Transfer | TCP 443, 1863
TCP/UDP 1025 - 65535 |
| File Transfer (Legacy) * | TCP 6891 - 6900 |
| Sharing Folders | TCP 1863 TCP/UDP 1025 – 65535 |
| Whiteboard and Application Sharing | TCP 1503 |
| Remote Assistance | TCP 3389
TCP/UDP 49152 – 65535 |
| Windows Live Call | TCP 443, 5061
UDP 5004 - 65525 |
| Games | TCP 80, 443, 1863
TCP/UDP 1025 - 65535 |
* These ports are used when you are connected to a contact through a legacy client program, such as MSN Messenger 5.0 or any version of Windows Messenger.
The following table lists the URLs to which Windows Live Messenger connects.
| URL used | URL function |
| https://Login.live.com (https://Login.live.com) | HTTP over SSL (HTTPS) authentication to Windows Live ID and acquiring of x509 certificates for secure peer-to-peer (p2p) connections for the Sharing Folders feature |
| http://Login.live.com (http://Login.live.com) | HTTP authentication to Windows Live ID |
| https://*.contacts.msn.com (https://*.contacts.msn.com) | To get the contact list |
| https://*.storage.msn.com (https://*.storage.msn.com) | Storage of the user tile, personal status message, and display name for a user so that the user can have the same set of information across all Windows Live experiences on work and home computers; (Simple Object Access Protocol [SOAP] over HTTPS) |
| http://*.storage.msn.com (http://*.storage.msn.com) | Storage of the user tile (HTTP DAV) and acquiring pictures from a user's Windows Live Space |
| http://c.msn.com (http://c.msn.com) | To set an anonymous unique ID for a user to personalize the Windows Live experience |
| http://*.messenger.msn.com (http://*.messenger.msn.com) | Various core messenger operations |
| http://g.msn.com (http://g.msn.com) | Redirect URLs used for tracking the start of a URL for a particular page to Microsoft Web sites |
| http://crl.microsoft.com (http://crl.microsoft.com) | To access the latest Certificate Revocation List (CRL) in order to check the validity of a certificate |
| http://messenger.hotmail.com:1863 (http://messenger.hotmail.com:1863) | Communications channel for messenger server; Microsoft Notification Protocol (MSNP) for messaging |
| http://gateway.messenger.hotmail.com (http://gateway.messenger.hotmail.com) | In case a firewall is blocking the ports, Messenger can use this gateway over HTTP |
| http://config.messenger.msn.com (http://config.messenger.msn.com) | Download configuration information that is used by the Messenger client |
| https://ows.messenger.msn.com (https://ows.messenger.msn.com) | Send offline messages |
| https://rsi.hotmail.com (https://rsi.hotmail.com) | Receive offline messages |
| http://sqm.microsoft.com (http://sqm.microsoft.com) | Upload Service Quality Monitoring (SQM) data to Microsoft; (no personally identifiable information [PII] is transferred) |
| http://*.edge.messenger.live.com (http://*.edge.messenger.live.com) | Various core Messenger operations. For example, echo servers that are used to establish direct connectivity between two messenger clients for peer-to-peer (p2p) communication when clients are behind firewalls |
| http://relay.data.edge.messenger.live.com (http://relay.data.edge.messenger.live.com) | Media relay used to transfer binary data (files, voice, or video) |
| http://rad.msn.com (http://rad.msn.com) | To download advertising content display in the client and to download ad-sponsored personal expression content, such as display pictures, and emoticons |
| http://appdirectory.messenger.msn.com (http://appdirectory.messenger.msn.com) | Used by Messenger activities/games applications that run inside Messenger applications |
| https://images.messenger.msn.com (https://images.messenger.msn.com) | For messenger image files |
| http://spaces.live.com (http://spaces.live.com) | For the contact card |
| http://relay.voice.messenger.msn.com (http://relay.voice.messenger.msn.com) | Media relay used for voice |
Users behind some authenticating proxy servers may experience sign-in issues. They might have to configure the proxy servers to force authentication for the following User Agent string:
MSN Explorer/9.0 (MSN 8.0; TmstmpExt).
To do this, users should see the documentation for their proxy server or contact their network administrator.