---
title: Appendix E: Glossary of ESAM Terms
slug: market-switching/appendix-e-glossary-of-esam-terms
docTags: 
createdAt: 2025-05-22T18:22:00.132Z
---

| **Acronym/Name ** | **Description**                                                                                                                                                                           |
| ---------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **ESAM**               | Event Scheduling and Metadata API – Cablelabs (v. I03) standard used for bridging communication between the Broadcaster and external SDS                                                  |
| **ESNI**               | Event Scheduling and Notification Interface – SCTE-224 standard used for scheduling content switches. This is an option for an SDS                                                        |
| **POIS**               | Placement Opportunity and Information Service – SCTE-130 standard with logic on how to create, modify, replace, delete, passthrough SCTE-35 messages                                      |
| **PSN**                | Process Status Notification – message sent from the ESAM Agent to the SDS notifying the SDS of the status/progress of the Agent completing the instructions sent in the SPN               |
| **SAS**                | Signal Acquisition Service – system that captures the SCTE-35 messages and is ESAM capable. The Broadcaster and ESAM Agent together make up Zixi’s SAS                                    |
| **SDS**                | Signal Decision Service – external system with schedule or logic for handling SCTE-35 messages. Also, can send unsolicited commands to the Agent for immediate switches or SCTE creation  |
| **SPE**                | Signal Processing Event – message sent from the ESAM Agent to the SDS requesting instructions                                                                                             |
| **SPN**                | Signal Processing Notification – message from the SDS to the ESAM Agent with instructions (solicited or unsolicited)                                                                      |