This update addresses the "Windows XP Real-Time Communication Client Support for Network Address Translation" issue in Windows XP, and is discussed in Microsoft Knowledge Base (KB) Article Q316397. Download now to resolve several issues in the Windows Messenger Client and to eliminate popping sounds coming from your speakers. This update also enables users of the Voice.Net service to reach the telephony service from behind Network Address Translators (NATs).
For more information about this issue, read Microsoft KB Article Q316397. (This site is in English.)