Persistent Shared Object Model

PSOM Shared Object Messaging (often referred to as PSOM), is a Microsoft Protocol used in Web Conferencing with Microsoft's OCS 2007 and Live Meeting Console products. PSOM is used to download content for a web conferencing client (i.e. Live Meeting Console). PSOM uses port 8057 (over TLS) to listen for PSOM connections from Live Meeting console web conferencing client

Protocol documentation is available in Microsoft's Open Specifications library, where it is referenced as MS-PSOM.