[MS-OCPSTN]: Session Initiation Protocol (SIP) for PSTN Calls Extensions https://docs.microsoft.com/en-us/openspecs/office_protocols/MS-OCPSTN/6e69d8d4-ba59-484f-9f2f-61d8ee4ed0d9 Specifies the Session Initiation Protocol (SIP) Extensions for PSTN Calls, which is a set of extensions for interfacing a client with other traditional telephony networks, such as the Public Switched Telephone Network (PSTN) and an Internet Protocol Private Branch eXchange (IP-PBX) or enterprise PBX. Major Update for [MS-OCPSTN] (Version 9.0) https://docs.microsoft.com/en-us/openspecs/office_protocols/MS-OCPSTN/6e69d8d4-ba59-484f-9f2f-61d8ee4ed0d9 <b>Protocol Revision:</b> 9.0<br/><b>Downloads:</b><br/><ul style="list-style-type: square;"><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN].pdf">PDF</a></li><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN]-210817.docx">DOCX</a></li></ul> Tue, 17 Aug 2021 MS-OCPSTN-20210817 No Update for [MS-OCPSTN] (Version 8.0) https://docs.microsoft.com/en-us/openspecs/office_protocols/MS-OCPSTN/6e69d8d4-ba59-484f-9f2f-61d8ee4ed0d9 <b>Protocol Revision:</b> 8.0<br/><b>Downloads:</b><br/><ul style="list-style-type: square;"><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN]-190618.pdf">PDF</a></li><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN]-190618.docx">DOCX</a></li></ul> Tue, 18 Jun 2019 MS-OCPSTN-20190618 Major Update for [MS-OCPSTN] (Version 8.0) https://docs.microsoft.com/en-us/openspecs/office_protocols/MS-OCPSTN/6e69d8d4-ba59-484f-9f2f-61d8ee4ed0d9 <b>Protocol Revision:</b> 8.0<br/><b>Downloads:</b><br/><ul style="list-style-type: square;"><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN]-180828.pdf">PDF</a></li><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN]-180828.docx">DOCX</a></li></ul> Tue, 28 Aug 2018 MS-OCPSTN-20180828 Major Update for [MS-OCPSTN] (Version 7.0) https://docs.microsoft.com/en-us/openspecs/office_protocols/MS-OCPSTN/6e69d8d4-ba59-484f-9f2f-61d8ee4ed0d9 <b>Protocol Revision:</b> 7.0<br/><b>Downloads:</b><br/><ul style="list-style-type: square;"><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN]-180724.pdf">PDF</a></li><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN]-180724.docx">DOCX</a></li></ul> Tue, 24 Jul 2018 MS-OCPSTN-20180724 Major Update for [MS-OCPSTN] (Version 6.0) https://docs.microsoft.com/en-us/openspecs/office_protocols/MS-OCPSTN/6e69d8d4-ba59-484f-9f2f-61d8ee4ed0d9 <b>Protocol Revision:</b> 6.0<br/><b>Downloads:</b><br/><ul style="list-style-type: square;"><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN]-180427.pdf">PDF</a></li><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN]-180427.docx">DOCX</a></li></ul> Fri, 27 Apr 2018 MS-OCPSTN-20180427 No Update for [MS-OCPSTN] (Version 5.0) https://docs.microsoft.com/en-us/openspecs/office_protocols/MS-OCPSTN/6e69d8d4-ba59-484f-9f2f-61d8ee4ed0d9 <b>Protocol Revision:</b> 5.0<br/><b>Downloads:</b><br/><ul style="list-style-type: square;"><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN]-160929.pdf">PDF</a></li><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN]-160929.docx">DOCX</a></li></ul> Thu, 29 Sep 2016 MS-OCPSTN-20160929 No Update for [MS-OCPSTN] (Version 5.0) https://docs.microsoft.com/en-us/openspecs/office_protocols/MS-OCPSTN/6e69d8d4-ba59-484f-9f2f-61d8ee4ed0d9 <b>Protocol Revision:</b> 5.0<br/><b>Downloads:</b><br/><ul style="list-style-type: square;"><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN]-160914.pdf">PDF</a></li><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN]-160914.docx">DOCX</a></li></ul> Wed, 14 Sep 2016 MS-OCPSTN-20160914 No Update for [MS-OCPSTN] (Version 5.0) https://docs.microsoft.com/en-us/openspecs/office_protocols/MS-OCPSTN/6e69d8d4-ba59-484f-9f2f-61d8ee4ed0d9 <b>Protocol Revision:</b> 5.0<br/><b>Downloads:</b><br/><ul style="list-style-type: square;"><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN]-160715.pdf">PDF</a></li><li><a href="https://interoperability.blob.core.windows.net/files/MS-OCPSTN/[MS-OCPSTN]-160715.docx">DOCX</a></li></ul> Fri, 15 Jul 2016 MS-OCPSTN-20160715