Copyright (c) 2021 T-Mobile
Copyright (c) 2017 Intel Corporation
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
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Description Reference Git Tag E-UTRAN Initial Attach 5.3.2.1-1 Stable Tracking Area Update procedure with Serving GW change 5.3.3.1-1 Experimental Tracking Area Update procedure with Serving GW change and data forwarding 5.3.3.1A-1 Experimental E-UTRAN Tracking Area Update without S‑GW Change 5.3.3.2-1 Stable UE triggered Service Request 5.3.4.1-1 Stable Network Triggered Service Request 5.3.4.3-1 Experimental eNodeB initiated Connection Suspend procedure 5.3.4A-1 Stable MO Data transport in NAS PDU 5.3.4B.2-1 Experimental MT Data transport in NAS PDUs 5.3.4B.3-1 Experimental Establishment of S1-U bearer during Data Transport in Control Plane CIoT EPS Optimisation 5.3.4B.4-1 Experimental S1 Release Procedure 5.3.5-1 Stable UE initiated Connection Resume procedure 5.3.5A-1 Stable MME-Initiated Detach Procedure 5.3.8.3-1 Stable HSS-Initiated Detach Procedure 5.3.8.4-1 Stable Dedicated Bearer Activation Procedure 5.4.1-1 Stable Bearer Modification Procedure with Bearer QoS Update 5.4.2.1-1 Stable HSS Initiated Subscribed QoS Modification 5.4.2.2-1 Experimental Bearer Modification Procedure without Bearer QoS Update 5.4.3-1 Stable PDN GW Initiated Bearer Deactivation 5.4.4.1-1 Stable MME initiated Dedicated Bearer Deactivation 5.4.4.2-1 Stable UE requested bearer resource modification 5.4.5-1 Stable E-UTRAN initiated E-RAB modification procedure 5.4.7-1 Stable X2-based handover without Serving GW relocation 5.5.1.1.2-1 Stable X2-based handover with Serving GW relocation 5.5.1.1.3-1 Stable S1-based handover 5.5.1.2.2-1 Experimental S1-based handover, Reject 5.5.1.2.3-1 Experimental Inter RAT handover Cancel 5.5.2.5.2-1 Experimental GW Secondary RAT usage data Reporting procedure 5.7A.3-2 Stable Notification of the ECGI, TAI and/or user CSG information changes 5.9.2.1-1 Stable UE requested PDN connectivity 5.10.2-1 Stable UE or MME requested PDN disconnection 5.10.3-1 Stable MME triggered Serving GW relocation 5.10.4-1 Stable Dedicated bearer activation in combination with the default bearer activation at attach or UE requested PDN connectivity F.1 Experimental
Description Git Tag User Level Packet Copying Stable Mobility (Promotion/Demotion) SAEGW <-> PGW, SAEGW <-> SGW Stable Predefined Rules Stable TEID Range Support Stable Restoration support utilizing FQ-CSID’s Stable Restoration for CP (SGW-C, PGW-C & SAEGW-C) failures Stable Gx Support for SAEGW-C and PGW-C Stable libgtpv2c for S11 and S5/S8 interfaces Stable libpfcp for Sxa, Sxb and SxaSxb interfaces Stable REST based CLI for CP & DP Stable APN and Distributed Deployment Support Stable User Plane Discovery (DNS) Stable Billing (via Sx, utilizing Redis w/SGX) Stable Event Reporting Funciton Stable IPv6, IPv4V6 support in Mobility Management Experimental IPv6 interface support for S11, S5/S8, S1-U, SGI-LAN and Sx interfaces Experimental
- Introduction
Evolved Packet Core (EPC) is a critical node in the wireless infrastructure, which provides the data services to the end users. The NGIC is a virtualized application providing the same service as the standalone node. User plane node for the EPC which deals with converged voice and data services on Long Term Evolution (LTE) networks.This has been developed using data plane development kit version 18.02 (DPDK) optimized for Intel Architecture. It supports CUPS architecture. CUPS means Control and User Plane Separation of EPC nodes and provides the architecture enhancements for the separation of functionality in the Evolved Packet Core’s SGW and PGW. This enables flexible network deployment and operation, by distributed or centralized deployment and the independent scaling between control plane and user plane functions.
EPC Core
+-------------------------+
| +---------+ +---------+ |
Control| | MME | | PCRF | |
Signal| | | | | |
+----------+ +-------+ | | | |
+--+ | | | | +-----+---+ +---+-----+ |
|UE+-----+ | | | | | |
+--+ | | | | +-----------------+ |
| +--+ | | |s11 |Gx | |
+--+ | eNodeB +--+ | | +-------------+ | |
|UE+-----+ (Base | | | | | CP | | |
+--+ | Station)| | | | +-------------+ | | +--------------+
| | | |s1u| +-------------+ |sgi| | External |
+--+ | | +---------+ | DP | +-------+ Network |
|UE+-----+ | User | | +-------------+ | | | |
+--+ +----------+ Data | | NGIC NFV | | | |
|| | +-----------------+ | +--------------+
|| +-------------------------+
||
++
Figure 1. EPC Core Architecture
The DPDK IP Pipeline Framework provides a set of libraries to build a pipeline application. In this document, NGIC will be explained in detail with its own building blocks.
This document assumes the reader possesses the knowledge of DPDK concepts and packet framework. For more details, read DPDK's Getting Started Guide, Programmers Guide, Sample Applications Guide.
- Scope
NGIC can be run on variety of servers running as a standalone application or on a virtual machine using SRIOV and OVS dpdk as a NFVi layer. It supports SGWC, PGWC, SGWU, PGWU, SAEGWC and SAEGWU modes of the servers. SAEGWC and PGWC communicates with PCRF and SGWC/PGWC/SAEGWC communicates with DNS for selecting User Plane nodes.
- Feature List
The NGIC VNF currently supports the following features:
- IPv6 interfaces and applications support in Deployment models
- IPv6 support in Mobility Management
- User level packet copying
- TEID implementation as per "C3PO TEID Assignment and Recovery Scenarios"
- Restoration CSID implementation and UP recovery
- UPF selection by DNS
- Handover scenarios
- Predefined Rules
- libgtpv2c auto generated code on S11 and S5/S8 interfaces
- libpfcp auto generated code integration on SxaSxb, Sxa, Sxb interfaces
- CLI and statistics parameters
- Peer echo and request timers
- Multi node connectivity support in control plane and user plane
- E-UTRAN procedures
- PCC (Policy Control and Charging) rules configuration.
- Packet Filters for Service Data Flow (SDF) configuration.
- UE sessions with multiple Bearer support
- IPv4 support
- Charging by volume and time notification
- Enable command line or display stats periodically
- Promotion Demotion
- High Level Design
The NGIC VNF application is divided into Control plane (CP) and Data plane (DP). Please refer to Figures below for the basic architecture in the NGIC.
+--------------+ +---------------+
| | | |
+------->+ +------------>+ |
S11 | SAEGWC | GX | PCRF |
<--------+ <-------------+ |
| | | |
+----+-----+---+ +---------------+
| ^
| SX |
| |
v |
+----+-----+---+
| |
+------->+ +------------>
S1U | SAEGWU | SGI
<--------+ +<-----------+
| |
+--------------+
Figure 2. Combined Gateway Architecture
+--------------+ +---------------+ +--------------+
| | | | | |
+------->+ +------------>+ +---------->+ |
S11 | SGWC | S5S8C | PGWC | GX | PCRF |
<--------+ <-------------+ +<----------+ |
| | | | | |
+----+-----+---+ +----+------+---+ +--------------+
| ^ | ^
| SXA | | SXB |
| | | |
v | v |
+----+-----+---+ +----+------+---+
| | | |
+------->+ +------------>+ +---------->
S1U | SGWU | S5S8U | PGWU | SGI
<--------+ +<------------+ +<---------+
| | | |
+--------------+ +---------------+
Figure 3. Split Gateway Architecture
+----------------+
| |
| |
| DNS |
| |
| |
+----+-------+---+
^ |
| |
| |
| |
| v
+----+-------+----+ +-------------------+
| | | |
| SGWC +----------->+ |
| PGWC | | REDIS-SGX |
| SAEGWC | | |
| +<-----------+ |
+-----------------+ +-------------------+
Figure 4. Control Plane With DNS and Redis Server
+--------+ +--------+ +-------+
| | | | | |
| +------->+ +--------->+ |
+----------+ | D-ADMF | | ADMF | | LEGACY|
| | | +<-------+ +<---------+ ADMF |
| Control +<------+ | | | | |
| Plane | +--------+ +--------+ +-------+
| |
+-----+----+
|
|
|
| +--------+ +--------+ +-------+
| | | | | | |
| X2 Events | +------->+ +---------->+ |
+------------>+ D-DF2 | | DF2 | | LEGACY|
| +<-------+ +<----------+ DF2 |
+------------>+ | | | | |
| X2 Events +--------+ +--------+ +-------+
|
|
+-----+---+
| |
| User |
| Plane | +--------+ +--------+ +-------+
| +--------->+ | | | | |
+---------+ | +--------> +---------->+ |
| D-DF3 | | DF3 | | LEGACY|
| | | | | DF3 |
| +<-------+ +<----------+ |
+--------+ +--------+ +-------+
Figure 5. Control Plane and User Plane with User Level Packet Copying Components
- Build, install, configure and test
Please refer to Control and User Plane Gateway User Guide.
- Known Issues and limitations
-
ICMP supported under KNI-Linux -
IPV4/IPV6 fragmentation and option header not supported. -
IPSec not supported. -
ARP handling supported under KNI-Linux. -
QoS Control in User Plane is not supported. -
ISR procedure is not supported. -
Multimedia Priority Service is not supported