DOCUMENT:Q235683 22-JUN-2001 [exchange] TITLE :XWEB: OWA Uses Client RPC Binding Order to Set Up Communication PRODUCT :Microsoft Exchange PROD/VER:WINDOWS:5.5 OPER/SYS: KEYWORDS: ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Outlook Web Access, version 5.5 - Microsoft Outlook Web Access, version 5.5 Service Packs 1, 2, 3 - Microsoft Exchange Server, version 5.5 ------------------------------------------------------------------------------- SUMMARY ======= Microsoft Exchange Server uses remote procedure call (RPC) built into Microsoft Windows NT to establish connections among the Exchange Server processes, such as connections between Exchange Server message transfer agents (MTAs), and to connect Exchange clients and Exchange Server computers in the network. Exchange Server can use RPC over named pipes, TCP/IP, NetBIOS, and IPX/SPX. When Exchange Server uses RPC, it proceeds through the list of the protocols above and establishes RPC binding. The preference order of the transports is defined by the "RPC BINDING ORDER," which by default is Local RPC, TCP/IP, SPX, named pipes, and then NetBIOS, in order of preference. Outlook Web Access (OWA) uses the Outlook/Exchange client RPC binding order to establish RPC communications to the Exchange Server, the same way that an Exchange or Outlook client does. RPC_Binding_Order is located in the registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Exchange\Exchange Provider MORE INFORMATION ================ When you set up OWA and Exchange Server on different computers, OWA connects to the Exchange Server computer and uses the protocols listed in the binding order until it establishes communication with the server or until it runs out of protocols as described above. If OWA runs out of protocols and fails to connect you may receive the following error message: Unable To Get Your Inbox. For additional information about changing the binding order, please see the following article(s) in the Microsoft Knowledge Base: Q163576 XGEN: Changing the RPC Binding Order Additional query words: ====================================================================== Keywords : Technology : kbOutlookSearch kbOWASearch kbOWA550 kbOWA550SP1 kbOWA550SP2 kbOWA550SP3 Version : WINDOWS:5.5 Issue type : kbinfo ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.