LTE MBMS Gateway

1 Introduction

LTEMBMSGW is a LTE MBMS Gateway. It can easily be used with the Amarisoft LTE eNodeB to build an LTE MBMS test system.

2 Features

User configurable list of service and multicast components.
M2AP protocol support.
Generate one stream per service over the M1 interface (GTP + SYNC protocols).
Built-in test RTP packet generator.
Remote API using WebSocket.

3 Requirements

3.1 Hardware requirements

LTEMBMSGW can run on the same PC as the Amarisoft eNodeB if a simple and compact solution is needed. Otherwise, any reasonnably recent PC with at least one Gigabit Ethernet port is acceptable.

3.2 Software requirements

A 64 bit Linux distribution. Fedora 39 is the officially supported distribution.
The following distributions are known as compatible:
- Fedora 22 to 39
- Cent OS 7
- Ubuntu 14 to 22
Your system requires at least GLIBC 2.17.

4 Installation

We assume that the Fedora distribution is running and that the network access thru the Gigabit Ethernet port is correctly configured.

LTEMBMSGW can be run directly from the directory when it was unpacked. No need for explicit installation.

4.1 Linux setup

4.1.1 Packages

LTEMBMSGW uses the SCTP protocol for which the necessary packages are not usually installed. In order to install them, do as root user:

Fedora

dnf install lksctp-tools kernel-modules-extra

Ubuntu
```
sudo apt-get install lksctp-tools linux-image-extra-3.13.0-24-generic
```
Note that linux-image-extra package name may differ depending on your kernel version.

To verify that SCTP kernel module is running, do as root user:

checksctp

If it reports that the protocol is not supported,

check if you have a /etc/modprobe.d/sctp-blacklist.conf file
edit it to comment the ’blacklist sctp’ line

Then reboot the PC in case the Linux kernel was upgraded too.

4.1.2 OpenSSL

LTEMBMSGW has been compiled against openssl version 1.1.1w.
If your system does not have compatible version installed you may have this error message at startup:

error while loading shared libraries: libssl.so.1.1: cannot open shared object file: No such file or directory

To overcome this problem, you may:

Copy libssl.so.1.1 and libcrypto.so.1.1 from libs subdirectory of your release tarball.
If you have installed software with automatic install script, this should have been done automatically.
Compile and install proper openssl version yourself

In case of persisting issue, raise a ticket from our support site at https://support.amarisoft.com/ with the information provided by below commands executed in LTEMBMSGW directory:

uname -a
ls -l
ldd ./ltembmsgw
openssl version

4.2 License key installation

LTEMBMSGW needs a LTEMME license key to run. Please refer to the ltemme documentation.

4.3 Initial testing

Start the eNodeB with the example MBMS configuration:
```
./lteenb config/enb-mbms.cfg
```
Start the program as root with the default configuration. This configuration contains several MBMS services. For each service, RTP dummy streams are generated:
```
./ltembmsgw config/mbmsgw.cfg
```
Verify that the MBMS GTP data is correctly received by the eNodeB with the mbms command in the eNodeB monitor. You should see a non zero bitrate for each service and zero packet error.
Verify that you can receive the corresponding services on your LTE device. The exact setup depend on your device.

When this basic test work, you can customize the eNodeB and MBMS Gateway configuration to use your own generated multicast services.

5 Configuration reference

5.1 Configuration file syntax

The main configuration file uses a syntax very similar to the Javascript Object Notation (JSON) with an extension to support complex numbers and a few mathematical operations. The supported types are:

- Numbers (64 bit floating point). Notation: 13.4
- Complex numbers. Notation: 1.2+3*I
- Strings. Notation: "string"
- Booleans. Notation: true or false.
- Objects. Notation: { field1: value1, field2: value2, .... }
- Arrays. Notation: [ value1, value2, .... ]

The basic operations +, -, * and / are supported with numbers and complex numbers.

The numbers 0 and 1 are accepted as synonyms for the boolean values false and true.

5.2 Properties

log_filename

String. Set the log filename. If no leading /, it is relative to the configuration file path. See Log file format.

log_options

String. Set the logging options as a comma separated list of assignments.

layer.level=verbosity. For each layer, the log verbosity can be set to none, error, info or debug. In debug level, the content of the transmitted data is logged.
layer.max_size=n. When dumping data content, at most n bytes are shown in hexa. For ASN.1, NAS or Diameter content, show the full content of the message if n > 0.
layer.payload=[0|1]. Dump ASN.1, NAS, SGsAP or Diameter payload in hexadecimal.
layer.key=[0|1]. Dump security keys (NAS and RRC layers).
layer.crypto=[0|1]. Dump plain and ciphered data (NAS and PCDP layers).
time=[sec|short|full]. Display the time as seconds, time only or full date and time (default = time only).
time.us=[0|1]. Dump time with microseconds precision.
file=cut. Close current file log and open a new one.
file.rotate=now. Rename current log with timestamp and open new one.
file.rotate=size. Rename current log every time it reaches size bytes open new one. Size is an integer and can be followed by K, M or G.
file.path=path. When log rotation is enabled, move current log to this path instead of initial log path.
append=[0|1]. (default=0). If 0, truncate the log file when opening it. Otherwise, append to it.

Available layers are: gtpu, m2ap

log_sync

Optional boolean (default = false). If true, logs will be synchronously dumped to file.
Warning, this may lead to performances decrease.

com_addr

Optional string. Address of the WebSocket server remote API. See Remote API.
If set, the WebSocket server for remote API will be enabled and bound to this address.
Default port is 9004.
Setting IP address to [::] will make remote API reachable through all network interfaces.

com_name

Optional string. Sets server name. MBMSGW by default

com_ssl_certificate

Optional string. If set, forces SSL for WebSockets. Defines CA certificate filename.

com_ssl_key

Optional string. Mandatory if com_ssl_certificate is set. Defines CA private key filename.

com_ssl_peer_verify

Optional boolean (default is false). If true, server will check client certificate.

com_ssl_ca

Optional string. Set CA certificate. In case of peer verification with self signed certificate, you should use the client certificate.

com_log_lock

Optional boolean (default is false). If true, logs configuration can’t be changed via config_set remote API.

com_log_us

Optional boolean (default is false). If true, logs sent by log_get remote API response will have a timestamp_us parameters instead of timestamp

com_auth

Optional object. If set, remote API access will require authentication.
Authentication mechanism is describe in Remote API Startup section.

passfile: Optional string. Defines filename where password is stored (plaintext).
If not set, password must be set
password: Optional string. Defines password.
If not set, passfile must be set.
unsecure: Optional boolean (default false). If set, allow password to be sent plaintext.
NB: you should set it to true if you access it from a Web Browser (Ex: Amarisoft GUI) without SSL (https) as your Web Browser may prevent secure access to work.

com_log_count

Optional number (Default = 8192). Defines number of logs to keep in memory before dropping them.
Must be between 4096 and 2097152).

sim_events

Array of object. Each element gives an event configuration to execute for this UE.
Event configuration is exactly the same as for Remote API messages except that message field must be event.

sim_events_loop_count

If set, will define loop_count for each event of sim_events, See loop_count.

sim_events_loop_delay

If set, will define loop_delay for each event of sim_events, See loop_delay.

license_server

Configuration of the Amarisoft license server to use.
Object with following properties:

server_addr: String. IP address of the license server.
name: Optional string. Text to be displayed inside server monitor or remote API.
tag: Optional string. If set, server will only allow license with same tag.

Example:

license_server: {
    server_addr: "192.168.0.20",
    name: "My license"
}

gtp_bind_addr

String. Set source IP address (and an optional port) of the GTP-U packets. The default value is "0.0.0.0:2152".

Syntax:

- "1.2.3.4" (use default port)
- "1.2.3.4:5678" (use explicit port)
- "2001:db8:0:85a3::ac1f:8001" (IPv6 address and default port)
- "[2001:db8:0:85a3::ac1f:8001]:5678" (IPv6 address and explicit port)

m2ap_bind_addr

Optional string. IP address and optional port on which the M2AP SCTP connection is bound. The default port is 36443.

mce_id

Integer. Range: 0 to 65535. Global MCE Identifier used in M2 signaling.

enb_time_offset

Optional integer (default = 0). Offset in ms applied to the MBMSGW International Atomic Time (TAI) so as to generate a time that should match the eNB RF time. The current value can be retrieved by typing the time monitor command in eNB or MBMSGW prompt. This is used to synchronize the two components so as to have meaningful timestamps in the SYNC packets (indicating the start of the MCH Scheduling Periods).

Note: the MBMSGW derives the TAI from the UTC OS clock and the right/UTC OS time zone.

time_offset

Integer. Default time offset in ms added to all the SYNC timestamps. Can be overridden by the time_offset property of each service. It is recommended to set it to at least 2 MCH Scheduling Period to avoid having the eNB dropping SYNC packets due to a timestamp equal to the current MCH Scheduling Period.

Note: the MBMS Gateway uses the system real time clock as clock source. If synchronous transmission is needed, it should be synchronized to the eNodeB RF time.

services

Array of objects. Contain the definition of each service.

Property of each service:

tmgi

Object. Service identifier (only used for error reporting). Contain the following fields:

plmn: String (5 or 6 digits). PLMN identity of the service.
service_id: Integer. 24 bit service identity.

service_area_id

Integer. Range: 0 to 65535. MBMS service area identifier for this service.

session_id

Optional integer. Range: 0 to 255. MBMS session identifier for this service.

gtp_addr

String. IP address (and optional port) to which the GTP packets are sent. It is normally a multicast address. Several services can share the same IP address if they have a different TEID.

gtp_teid

32 bit integer. GTP TEID on which the GTP packets are sent.

autostart

Optional boolean (default = true). Indicates if service is automatically started when the eNB connects to the MBMS Gateway or if it should be manually launched with the service_start command.

scheduling_period

Range: from 4 to 1024. Must be a power of two. Duration of the scheduling period in 10 ms units. Must match the corresponding MCH scheduling period configured in the eNodeB.

time_offset

Optional integer. Time offset in ms added to the SYNC timestamps. If not provided, the default time offset is used.

forward_mode

Optional boolean (default = false). If set, gateway won’t add sync headers and only forward packet to the eNB.

tos

Optional integer (default = 0). IPv4 header TOS field (6 bits DSCP + 2 bits ECN).

traffic_class

Optional integer (default = 0). IPv6 header traffic class field (6 bits DSCP + 2 bits ECN).

ttl

Optional integer (default = 64). IP header TTL field.

components

Array of object. A service contains several components. Each component is the data coming from a given IP address (usually multicast).

Component properties:

ip_addr: String. Destination IPv4/v6 address and port for the component.
if_addr: Optional string (default = "0.0.0.0"). IP address of the network interface for the multicast join.
sim: Optional boolean (default = false). If true, RTP packets coming from ip_addr are generated using a RTP payload of rtp_payload_len bytes and a bitrate of bitrate.
rtp_payload_len: Optional integer. Only meaningful if sim = true. RTP payload length in bytes (default = 1460).
bitrate: Optional integer. Only meaningful if sim = true. Bitrate in bit/s of the generated RTP stream. The bitrate includes the size of the IP, UDP and RTP headers.

area_info_list

Array of object. Each object defines the parameters of one MBSFN area:

area_id

Range: 0 to 255. Area identifier.

non_mbsfn_region_length

Enumeration: 1, 2. Number of CCH symbols. For 1.4 MHz downlink, only 2 is allowed.

mcch_config

Object. MCCH configuration:

mcch_repetition_period: Range: 32 to 256, power of two. MCCH repetition period (in 10 ms frames).
mcch_offset: Range: 0 to 10. MCCH offset.
mcch_modification_period: Enumeration: 512, 1024. (in 10 ms frames).
mcch_sf_alloc: Bit string. Length = 6 (1 frame). In FDD, the bits correspond to subframes 1, 2, 3, 6, 7, 8. In TDD, the bits correspond to subframes 3, 4, 7, 8, 9.
signalling_mcs: Enumeration: 2, 7, 13, 19. MCS for MCCH and MCHSI transmission. MCCH and MCHSI are critical to decode the MBMS data (MTCH), so their MCS should be lower than the one of the data.

mbsfn_area_configuration

Object. MBSFN area configuration. Most of the content of this object is transmitted in the MCCH.

common_sf_alloc

Array of object. Defines the subframes dedicated to this MBSFN area. Each object has the following fields:

radio_frame_allocation_period: Range: 1 to 32, power of two. Allocation period (in 10 ms frames).
radio_frame_allocation_offset: Range: 0 to 7. offset in the allocation period (in 10 ms frames).
subframe_allocation: Bit string. Length = 6 (1 frame) or 24 (4 frames). In FDD, the bits correspond to subframes 1, 2, 3, 6, 7, 8. In TDD, the bits correspond to subframes 3, 4, 7, 8, 9.

common_sf_alloc_period

Range: 4 to 256, power of two. Common subframe allocation period (in 10 ms frames). The PMCH are allocated consecutively during this period.

pmch_info_list

Array of objects. List of PMCH. Each PMCH has the following properties:

pmch_config

Object. PMCH physical parameters.

sf_alloc_count: Integer >= 1. Number of subframes allocated to this PMCH per common period.
data_mcs: Range: 0 to 28. MCS used for the MBMS data (MTCH).
data_mcs2: Optional integer. Range: 0 to 27. If provided, data_mcs is ignored and an alternate MCS table is used to allow 256QAM MBMS. Note: 256QAM MBMS is an optional release 12 feature, so not all UEs can receive a PMCH using data_mcs2.
mch_scheduling_period: Range: 4 to 1024, power of two. Scheduling period (in 10 ms frames) for the MCH. MCHSI is transmitted with this periodicity. Must be >= common_sf_alloc_period. For the first PMCH, must be <= mcch_repetition_period. Note: only release 12 UEs support the value 4, so the effective range to support all UEs is 8 to 1024.

mbms_session_info_list

Array of objects. List of sessions in this PMCH. Each session has the following properties:

tmgi

Object. Temporary Mobile Group Identity.

plmn: String (5 or 6 digits). PLMN identity.
service_id: 24 bit integer. Service identity.

logical_channel_identity

Range: 0 to 28. MAC logical channel identity. Must be different for each session in the PMCH. 0 is reserved for the MCCH in the first PMCH.

6 Remote API

You can access LTEMBMSGW via a remote API.
Protocol used is WebSocket as defined in RFC 6455 (https://tools.ietf.org/html/rfc6455).

Note that Origin header is mandatory for the server to accept connections.
This behavior is determined by the use of nopoll library.
Any value will be accepted.

6.1 Messages

Messages exchanged between client and LTEMBMSGW server are in strict JSON format.

Each message is represented by an object. Multiple message can be sent to server using an array of message objects.

Time and delay values are floating number in seconds.

There are 3 types of messages:

Request
Message sent by client.
Common definition:

message

String. Represent type of message. This parameter is mandatory and depending on its value, other parameters will apply.

message_id

Optional any type. If set, response sent by the server to this message will have same message_id. This is used to identify response as WebSocket does not provide such a concept.

start_time

Optional float. Represent the delay before executing the message.
If not set, the message is executed when received.

absolute_time

Optional boolean (default = false). If set, start_time is interpreted as absolute.
You can get current clock of system using time member of any response.

standalone

Optional boolean (default = false). If set, message will survive WebSocket disconnection, else, if socket is disconnected before end of processing, the message will be cancelled.

loop_count

Optional integer (default = 0, max = 1000000). If set, message will be repeated loop_count time(s) after loop_delay (From message beginning of event).
Response will have a loop_index to indicate iteration number.

loop_delay

Optional number (min = 0.1, max = 86400). Delay in seconds to repeat message from its start_time. Mandatory when loop_count is set > 0.
Response
Message sent by server after any request message as been processed.
Common definition:

message

String. Same as request.

message_id

Optional any type. Same as in request.

time

Number representing time in seconds since start of the process.
Usefull to send command with absolute time.

utc

Number representing UTC seconds.
Events
Message sent by server on its own initiative.
Common definition:

message

String. Event name.

time

Number representing time in seconds.
Usefull to send command with absolute time.

6.2 Startup

When WebSocket connections is setup, LTEMBMSGW will send a first message with name set to com_name and type set to MBMSGW.

If authentication is not set, message will be ready:

{
    "message": "ready",
    "type": "MBMSGW",
    "name": <com_name>,
    "version": <software version>,
    "product": <Amarisoft product name (optional)>
}

If authentication is set, message will be authenticate :

{
    "message": "authenticate",
    "type": "MBMSGW",
    "name": <com_name>,
    "challenge": <random challenge>
}

To authenticate, the client must answer with a authenticate message and a res parameter where:

res = HMAC-SHA256( "<type>:<password>:<name>", "<challenge>" )

res is a string and HMAC-SHA256 refers to the standard algorithm (https://en.wikipedia.org/wiki/HMAC)

If the authentication succeeds, the response will have a ready field set to true.

{
    "message": "authenticate",
    "message_id": <message id>,
    "ready": true
}

If authentication fails, the response will have an error field and will provide a new challenge.

{
    "message": "authenticate",
    "message_id": <message id>,
    "error": <error message>,
    "type": "MBMSGW",
    "name: <name>,
    "challenge": <new random challenge>
}

If any other message is sent before authentication succeeds, the error "Authentication not done" will be sent as a response.

6.3 Errors

If a message produces an error, response will have an error string field representing the error.

6.4 Sample nodejs program

You will find in this documentation a sample program: ws.js.
It is located in doc subdirectory.
This is a nodejs program that allow to send message to LTEMBMSGW.
It requires nodejs to be installed:

dnf install nodejs npm
npm install nodejs-websocket

Use relevant package manager instead of NPM depending on your Linux distribution.

Then simply start it with server name and message you want to send:

./ws.js 127.0.0.1:9004 '{"message": "config_get"}'

6.5 Common messages

config_get

Retrieve current config.

Response definition:

type

Always "MBMSGW"

name

String representing server name.

logs

Object representing log configuration.
With following elements:

layers

Object. Each member of the object represent a log layer configuration:

layer name

Object. The member name represent log layer name and parameters are:

level: See log_options
max_size: See log_options
key: See log_options
crypto: See log_options
payload: See log_options

count

Number. Number of bufferizer logs.

rotate

Optional number. Max log file size before rotation.

path

Optional string. Log rotation path.

bcch

Boolean. True if BCCH dump is enabled (eNB only).

mib

Boolean. True if MIB dump is enabled (eNB only).

locked

Optional boolean. If true, logs configuration can’t be changed with config_set API.

config_set

Change current config.
Each member is optional.
Message definition:

logs: Optional object. Represent logs configuration. Same structure as config_get (See config_get logs member).
All elements are optional.
Layer name can be set to all to set same configuration for all layers.
If set and logs are locked, response will have logs property set to locked.

log_get

Get logs.
This API has a per connection behavior. This means that the response will depend on previous calls to this API within the same WebSocket connection.
In practice, logs that have been provided in a response won’t be part of subsequent request unless connection is reestablished. To keep on receiving logs, client should send a new log_get request as soon as the previous response has been received.
If a request is sent before previous request has been replied, previous request will be replied right now without considering specific min/max/timeout conditions.

Message definition:

min: Optional number (default = 1). Minimum amount of logs to retrieve.
Response won’t be sent until this limit is reached (Unless timeout occurs).
max: Optional number (default = 4096). Maximum logs sent in a response.
timeout: Optional number (default = 1). If at least 1 log is available and no more logs have been generated for this time, response will be sent.
allow_empty: Optional boolean (default = false). If set, response will be sent after timeout, event if no logs are available.
rnti: Optional number. If set, send only logs matching rnti.
ue_id: Optional number. If set, send only logs with matching ue_id.
layers: Optional Object. Each member name represents a log layer and values must be string representing maximum level. See log_options.
If layers is not set, all layers level will be set to debug, else it will be set to none.
Note also the logs is also limited by general log level. See log_options.
short: Optional boolean (default = false). If set, only first line of logs will be dumped.
headers: Optional boolean. If set, send log file headers.
start_timestamp: Optional number. Is set, filter logs older than this value in milliseconds.
end_timestamp: Optional number. Is set, filter logs more recent than this value in milliseconds.
max_size: Optional number (default = 1048576, i.e. 1MB). Maximum size in bytes of the generated JSON message. If the response exceeds this size, the sending of logs will be forced independently from other parameters.

Response definition:

logs

Array. List of logs. Each item is a an object with following members:

data: Array. Each item is a string representing a line of log.
timestamp: Number. Milliseconds since January 1st 1970. Not present if com_log_us is set in configuration.
timestamp_us: Number. Microseconds since January 1st 1970. Only present if com_log_us is set in configuration.
layer: String. Log layer.
level: String. Log level: error, warn, info or debug.
dir: Optional string. Log direction: UL, DL, FROM or TO.
ue_id: Optional number. UE_ID.
cell: Optional number (only for PHY layer logs). Cell ID.
rnti: Optional number (only for PHY layer logs). RNTI.
frame: Optional number (only for PHY layer logs). Frame number (Subframe is decimal part).
channel: Optional string (only for PHY layer logs). Channel name.
src: String. Server name.
idx: Integer. Log index.
headers: Optional array. Array of strings.

discontinuity

Optional number. If set, this means some logs have been discarded due to log buffer overflow.

microseconds

Optional boolean. Present and set to true if com_log_us is set in configuration file.

log_set

Add log.
Message definition:

log: Optional string. Log message to add. If set, layer and level are mandatory.
layer: String. Layer name. Only mandatory if log is set.
level: String. Log level: error, warn, info or debug. Only mandatory if log is set.
dir: Optional string. Log direction: UL, DL, FROM or TO.
ue_id: Optional number. UE_ID.
flush: Optional boolean (default = false). If set, flushes fog file.
rotate: Optional boolean (default = false). If set, forces log file rotation.
cut: Optional boolean (default = false). If set, forces log file reset.

log_reset

Resets logs buffer.

license

Retrieves license file information.

quit

Terminates ltembmsgw.

help

Provides list of available messages in messages array of strings and events to register in events array of strings.

stats

Report statistics for LTEMBMSGW.
Every time this message is received by server, statistics are reset.
Warning, calling this message from multiple connections simultaneously will modify the statistics sampling time.

Response definition:

cpu: Object. Each member name defines a type and its value cpu load in % of one core.
instance_id: Number. Constant over process lifetime. Changes on process restart.

6.6 LTE messages

service_start

Start a service.
Message definition:

service_id: Integer. Identifier of service to start.

service_stop

Stop a service.
Message definition:

service_id: Integer. Identifier of service to stop.

7 Log file format

7.1 M2AP and GTP-U layers

When a message is dumped, the format is:

time layer - message

When a data PDU is dumped (debug level), the format is:

time layer dir ip_address short_content
        long_content

time

Time using the selected format.

layer

Indicate the layer ([M2AP] or [GTPU] here).

dir

Direction: TO or FROM.

ip_address

source or destination IP address, depending on the dir field.

short_content

Single line content.

long_content

M2AP: full ASN.1 content of the M2AP message if layer.max_size > 0.
GTPU: hexadecimal dump of the message if layer.max_size > 0.

8 Change history

8.1 Version 2024-09-13

added license remote API
com_logs_lock parameter is renamed to com_log_lock. com_logs_lock is still supported for backward compatibility
added com_log_us parameter

8.2 Version 2024-06-14

OpenSSL library is upgraded to 1.1.1w

8.3 Version 2023-12-15

added loop_count and loop_delay to remote API messages
added sim_events, sim_events_loop_count and sim_events_loop_delay
added com_ssl_ca parameter for SSL verification

8.4 Version 2023-06-10

com_logs_lock parameter added to disable logs configuration change via remote API

8.5 Version 2023-03-17

com_addr parameter now uses [::] address instead of 0.0.0.0 in the delivered configuration file to allow IPv6 connection

8.6 Version 2022-12-16

utc parameter is added to remote API response messages

8.7 Version 2022-06-17

OpenSSL library is upgraded to 1.1.1n
m2ap_bind_addr parameter description is added
start_timestamp and end_timestamp are added to log_get API

8.8 Version 2021-12-17

license monitor command is added

8.9 Version 2021-09-17

the minimum GLIBC version is now 2.17
logs can be displayed with microseconds precision

9 License

ltembmsgw is available without any express or implied warranty. In no event will Amarisoft be held liable for any damages arising from the use of this software.

For more information on licensing, please refer to license.pdf file.

Abbreviations

MBMS: Multimedia Broadcast Multicast Service
SYNC: MBMS synchronisation protocol
TMGI: Temporary Mobile Group Identity

LTE MBMS Gateway

Table of Contents

1 Introduction

2 Features

3 Requirements

3.1 Hardware requirements

3.2 Software requirements

4 Installation

4.1 Linux setup

4.1.1 Packages

4.1.2 OpenSSL

4.2 License key installation

4.3 Initial testing

5 Configuration reference

5.1 Configuration file syntax

5.2 Properties

6 Remote API

6.1 Messages

6.2 Startup

6.3 Errors

6.4 Sample nodejs program

6.5 Common messages

6.6 LTE messages

7 Log file format

7.1 M2AP and GTP-U layers

8 Change history

8.1 Version 2024-09-13

8.2 Version 2024-06-14

8.3 Version 2023-12-15

8.4 Version 2023-06-10

8.5 Version 2023-03-17

8.6 Version 2022-12-16

8.7 Version 2022-06-17

8.8 Version 2021-12-17

8.9 Version 2021-09-17

9 License

Abbreviations