The following list describes predefined user context properties that are maintained by the server.
| Property name |
Description |
| NSS_USER_AGENT |
A String value describing the software used by the user to the server. It can be used to differentiate whether the connected user is Microsoft® Windows Media™ Player or another server. |
| NSS_USER_IP_ADDRESS |
A Long value containing the IP address of the user. The IP address often is not meaningful if it is masked by a firewall. The value of this property can change for different connections by the same client. |
| NSS_USER_CONTROL_PROTOCOL |
A String value containing the protocol to communicate with the client. Valid types include: MMS, RTSP, HTTP, and UNKNOWN. |
| NSS_USER_ID |
A String value containing the client ID. This ID corresponds with the ClientId property of the Windows Media Unicast service Admin control, and it can be used to disconnect the client. |
| NSS_USER_NAME |
A String value containing the user name. This property is only valid after the user has been successfully authenticated. |
| NSS_USER_AUTHENTICATOR |
A pointer to the IUnknown interface of the authenticator object that is used to authenticate the user. |
| NSS_USER_GUID |
A String value containing the client GUID. This GUID is generated when Windows Media Player is installed on the client computer. |
