IPsec problems when used in NTN network

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.¶

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.¶

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."¶

This Internet-Draft will expire on 8 January 2026.¶

Copyright Notice

Copyright (c) 2025 IETF Trust and the persons identified as the document authors. All rights reserved.¶

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.¶

Table of Contents

1. Introduction

The IPSEC protocol provides end-to-end security for IP networks by authenticating and encrypting IP packets to ensure the confidentiality, integrity, and authenticity of data during transmission. Under satellite Internet and NTN network, IPSEC is still a very important and commonly used security protocol. Due to the dynamic characteristics of satellites, there are also some problems in the use of IPsec.¶

This document describes the problems in the use of IPsec in satellite Internet and NTN network scenarios.¶

2. Terminology

3. IPsec used in NTN

For NTN network, the wireless access network defined in 3GPP is used with satellite network, UE can access data network via 3GPP wireless network and satellite network. NTN network supports gNB and UPF on satellites, UE connects to the base stations on satellites, and then connect to the core network through ground gateway stations.¶

The data transmission path between the wireless access network and the core network is called the backhaul link, used to transmit user data, signaling, and control information from the wireless access layer to the core network for processing, forwarding, and storage. When the position of the base station changes, it will affect the security of the return link. This document takes 5G as an example to analyse the use of ipsec problems existed in NTN network.¶

     +-------+     +---------+     +--------------+
UE---|Sat/gNB|-----| Gateway |-----| Core Network |
     +-------+     +---------+     +--------------+

      +----------+     +---------+     +--------------+
UE---|Sat/gNB+UPF|-----| Gateway |-----| Core Network |
     +-----------+     +---------+     +--------------+

Multiple security interfaces are involved in this network architecture, and the 3GPP standard(TS33.501) specifies the use of IPsec to solve end-to-end secure transmission issues. The interfaces related to the ipsec protocol are summurised in Table 1.¶

From the table, we can see that the security of these interfaces relies entirely on IPsec providing end-to-end transmission security. In NTN networks, there are some issues to use IPsec due to the dynamics of datellites.¶

4. Analysis of possible issues with continuing to use IPsec

Authors' Addresses