Description
The Port Management Information Container (PMIC) is a protocol data unit defined within the Packet Forwarding Control Protocol (PFCP) used on the N4 interface between the Session Management Function (SMF) and the User Plane Function (UPF) in the 5G Core. It is an Information Element (IE) carried within PFCP session modification or session establishment messages. The PMIC contains detailed information about the management of specific ports associated with a PDU session, particularly relevant for scenarios involving Ethernet-type PDU sessions or other data flows requiring explicit port control.
Architecturally, when the SMF needs to instruct the UPF to manage ports for a user plane connection—for example, to enable, disable, or configure parameters on a specific Ethernet port—it includes a PMIC within the relevant PFCP message. The container can specify the port number, the associated MAC address (for Ethernet), administrative status (up/down), and other port-specific attributes. The UPF, upon receiving this, applies the configuration to its user plane resources. This allows for granular control over the data forwarding environment at the UPF.
Its role is to enable the 5G Core to support services that require explicit layer 2 management, such as fixed-mobile convergence, industrial IoT with Ethernet backhaul, or network slicing with specific port-level isolation. The PMIC abstracts the port management details into a standardized container, ensuring interoperability between SMF and UPF from different vendors. It works in conjunction with other PFCP IEs that define packet detection rules, forwarding actions, and QoS enforcement to fully orchestrate the user plane path.
Purpose & Motivation
The PMIC was introduced to address the need for explicit port management within the 5G Core's user plane, a requirement that became prominent with the expansion of 5G to support non-IP PDU session types, particularly Ethernet. Previous mobile core architectures were primarily designed for IP-based traffic (GTP tunnels) where port management was implicit or handled at the IP layer. The support for Ethernet PDU sessions in 5G, driven by use cases like industrial automation and wireline convergence, required the ability to manage Ethernet switch ports within the UPF.
The problem it solves is the lack of a standardized mechanism for the control plane (SMF) to configure and manage physical or logical ports on the user plane function. Without the PMIC, managing Ethernet ports would require proprietary extensions, hindering multi-vendor interoperability and complicating service orchestration for fixed-access and enterprise scenarios.
Its creation was motivated by the 3GPP's work on supporting integrated access and backhaul (IAB), wireline-wireless convergence, and network slicing for vertical industries. These require the 5G system to act as a unified transport network capable of handling layer 2 protocols with the same level of programmability and control as traditional IP sessions. The PMIC provides this essential building block for port-level management within the standardized N4 protocol.
Classification
Detected Changes Across Releases
from 3GPP Change RequestsSpecific changes extracted from the „Change history“ tables of 3GPP specifications (256 CRs across 5 releases). Complements the general historical overview above with the evidence-based evolution of this function.
In Release 15, the PMIC function was introduced within the PFCP protocol to enable the management of Packet Flow Descriptions (PFDs) by the SMF, including procedures for PFD management and resolving the EN for PFD Management. This addition allowed for the provisioning and control of application detection and traffic steering rules, such as adding QFIs to the Packet Detection Information and utilizing AF-provided N6 traffic routing information. These enhancements provided a more granular mechanism for traffic influence and policy enforcement on the N4 interface between the SMF and UPF.
- Update of Provisioning of charging related information for PDU session TS 29.512CR0025
- Provisioning of IP index information TS 29.512CR0027
- Missing Slice Information TS 29.512CR0051
- Correction of 404 error information TS 29.512CR0093
- The SMF may allow traffic to start before quota management for online charging TS 29.512CR0178
- Correction to credit management session failure TS 29.512CR0187
+ 17 more changes
In Release 16, the PMIC function was enhanced to support Time Sensitive Networking (TSN) by introducing the transport of TSN information and containers between the SMF and PCF, as well as between the PCF and AF. Furthermore, clarifications were made regarding the management information for DS-TT and NW-TT ports, and Bridge management information was introduced. These updates expanded the PMIC's role in managing port information for integrated TSN and 5G systems.
- Transport of TSN information and containers between SMF and PCF TS 29.512CR0368
- Transport of TSC assistance information between SMF and PCF TS 29.512CR0369
- HFC node Id in Location information, TS 29.512 TS 29.512CR0390
- Clarification of DS-TT and NW-TT ports management information TS 29.512CR0425
- TSCAI input container and TSN QoS container TS 29.512CR0427
- CHF set and instance Id in charging information TS 29.512CR0431
+ 69 more changes
In Release 17, the PMIC (Port Management Information Container) function was enhanced to support new information elements and procedures over the N4mb reference point. Key additions included the ability to convey Transport Level Marking information for PFCP sessions and to report Redirect Port Information. Furthermore, specific enhancements were made for Multicast Broadcast Service (MBS) support, such as including the DL MBS QFI Sequence Number within the PDU Session Container.
- PMF address information per QoS flow TS 29.244CR0557
- PFCP Node related messages supported over N4mb TS 29.244CR0606
- Redirect Port Information TS 29.244CR0613
- Transport Level Marking information for PFCP sessions over N4mb TS 29.244CR0622
- DL MBS QFI Sequence Number in PDU Session Container TS 29.244CR0615
- PCC rules authorization with preliminary service information TS 29.512CR0809
+ 41 more changes
In Release 18, the PMIC function was enhanced to support new TL-Containers for TSN-enabled transport networks, which can now be included in PFCP Session Modification and Deletion procedures. Furthermore, the release introduced the direct reporting of TSC Management Information from the UPF to the TSN AF or TSCTSF. It also added capabilities for congestion information monitoring and exposure, including the encoding of UL/DL congestion information.
- Direct reporting of TSC Management Information from UPF to TSN AF or TSCTSF TS 29.244CR0725
- Congestion information monitoring TS 29.244CR0724
- Reporting suggestion information for QoS flow related QoS monitoring TS 29.244CR0733
- TL-Container for the support of TSN enabled Transport Network TS 29.244CR0734
- Exposure of congestion information TS 29.244CR0739
- PFCP extensions for HR-SBO PDU sessions TS 29.244CR0750
+ 55 more changes
In Release 19, the PMIC function was enhanced to support the transfer of media-related information over the N6 interface using connect-UDP and UDP Option methods. It also introduced the handling of (S)RTP Multiplexed Media Identification Information to manage multiplexed media streams. Furthermore, new capabilities were added for reporting QoS notification events with direction information and for handling Non-3GPP device information in the PCF.
- Supported functionality of NAT information exposure TS 29.244CR0876
- PFCP sessions excluded from the restoration upon a SMF failure with SMF set being deployed TS 29.244CR0895
- Transferring media related information over N6 using connect-UDP for e2e encrypted traffic TS 29.244CR0894
- Description for handling of allowed VLAN tags and use of VLAN Handling Information in SMF TS 29.244CR0884
- Providing alternative SMF(s) per PFCP Session TS 29.244CR0911
- Leveraging PDU Set QoS information for DSCP marking over N3/N9 in the transport network TS 29.244CR0912
+ 44 more changes
Explore further
Broader topics and technologies where PMIC plays a role.
Defining Specifications
3GPP specifications that define or reference PMIC, with the latest known release. Sourced from the 3GPP document catalog — see methodology.
| Specification | Title | Release |
|---|---|---|
| TS 29.244 vj40 | PFCP Specification for Control/User Plane Separation | Rel-19 |
| TS 29.512 vj40 | 5G Session Management Policy Control Service | Rel-19 |
| TS 29.513 vj40 | 5G PCC Signalling Flows & QoS Mapping | Rel-19 |
| TS 29.514 vj40 | 5G System; Policy Authorization Service; Stage 3 | Rel-19 |