# Distinguish Axis raw TCP serial access from remote port framing > Distinguish Axis Generic TCP/IP serial access from the specially framed remote-port function for multi-CPU encoders before choosing a network-to-serial integration path. - Canonical URL: https://update.dsesecurity.com/updates/distinguish-axis-raw-tcp-serial-access-from-remote-port-framing/ - Publisher: Detection Systems & Engineering (DSE Security) - Author: DSE Security Editorial Team - Published: 2026-10-29T17:41:17+00:00 - Modified: 2026-10-29T17:41:38+00:00 - Last reviewed by DSE: 2026-10-29 - Resource type: Guide - DSE priority: Advisory - Topics: Networks & Infrastructure, Video Surveillance - Reading time: 3 minutes ## What you need to know Distinguish Axis Generic TCP/IP serial access from the specially framed remote-port function for multi-CPU encoders before choosing a network-to-serial integration path. ## Potentially affected Axis products exposing the documented Serial port API interface; confirm actual device, hardware and software applicability before applying the proposed checks. ## DSE recommendation DSE recommends documenting the expected framing at both ends before enabling a network-to-serial path. ## Article Bottom line: Match the network client’s serial data expectations to the documented port function. Do not assume a remote-port connection is a raw TCP serial tunnel merely because both use a network socket. ## Source fact: documented behavior Axis’s [Serial port API](https://developer.axis.com/vapix/network-video/serial-port-api/) describes physical serial ports and remote-port clients, with a port manager able to share a port for uses such as PTZ control from multiple video channels. The remote-port function is intended only for multi-CPU video encoders and adds a protocol header to its data payload beyond Generic TCP/IP. In the Generic TCP server example, connected clients can send and receive raw data forwarded to and from the serial port. ## What the source does not establish Do not infer serial electrical compatibility, a third-party protocol implementation or safe network exposure from these descriptions. Obtain the exact product’s serial-port and connected-equipment documentation. Keep a raw-data path distinct from support for the attached equipment’s commands, and do not copy example listener ports or payloads into an active installation. ## Applicability questions - Which exact Axis product, physical serial interface and attached equipment are in scope? - Does the client expect raw serial payloads or the documented remote-port framing? - Is this a multi-CPU encoder use case or an external integration needing a different supported path? - Who approves serial settings, network access and the harmless test exchange? ## DSE recommendation: controlled next steps The following steps are DSE recommendations based on the cited source. DSE recommends documenting the expected framing at both ends before enabling a network-to-serial path. - Draw the intended path from the authorized client to the actual physical serial interface and attached equipment. Identify the selected Axis port function and port-manager relationship through the exact device’s supported configuration. Obtain the client’s documented framing expectation. Stop the design review if the selected function and client expectation cannot be reconciled; do not diagnose that mismatch by repeatedly changing baud rate. - Prepare an isolated test with qualified personnel and a harmless exchange approved for the attached equipment. Record serial settings and intended network restrictions before enabling any listener. Compare the transmitted and received data against the documented framing expectation. Avoid replaying example bytes from the API page when their meaning for the connected device has not been established. - Apply the approved port configuration through the supported workflow and test only the intended access path. Confirm the selected physical port and the allowed consumer, then inspect a permitted trace or equipment response. If another channel shares the port, review its required operation separately. Restore the approved configuration if the framing or equipment response remains uncertain rather than exposing additional listeners to make troubleshooting easier. ## Verification and evidence Retain the topology, exact product/software identity, selected port function, serial settings and references establishing each endpoint’s framing contract. Keep a bounded sanitized exchange with the test input and observed response. Label network connectivity and correct equipment operation as separate outcomes. Use a proposed desk case that pairs a raw-data client with the specially framed remote-port function and require the reviewer to identify the mismatch before implementation. For the actual pilot, record the approved exchange and any unresolved behavior. This article reports no serial test, protocol compatibility result or accepted network exposure. ## Official references - [Serial port API](https://developer.axis.com/vapix/network-video/serial-port-api/) — Axis Communications; official VAPIX documentation. Source review completed October 29, 2026. Recheck the official documentation and the deployed device’s capabilities before changing production settings. ## Primary reference - Name: Axis Communications — Serial port API - Authority: Axis Communications - URL: https://developer.axis.com/vapix/network-video/serial-port-api/ - Source publication date: Not stated by the source ## Citation and use Preferred citation: “Distinguish Axis raw TCP serial access from remote port framing,” DSE Security, https://update.dsesecurity.com/updates/distinguish-axis-raw-tcp-serial-access-from-remote-port-framing/ Publishing principles: https://update.dsesecurity.com/updates/dse-updates-editorial-methodology/ Usage and citation policy: https://update.dsesecurity.com/usage/ Copyright © 2026 Detection Systems & Engineering. All rights reserved.