3G Gateways User Manual

Address: 10/F, Building 6-A, Baoneng Science and Technology Industrial Park, Longhua New District, Shenzhen, Guangdong,China  518109

Tel: +86-755-82535461, 82535095, 82535362

Fax: +86-755-83823074

Business Contact: sales@openvox.cn

Technical Support: support@openvox.cn

Business Hours: 09:00-18:00(GMT+8) from Monday to Friday

URL: www.openvox.cn

1.  Overview

What is 3G Gateway?

OpenVox VoxStack Series 3G Gateway is an open source asterisk-based GSM VoIP Gateway solution for SMBs and SOHOs. With friendly GUI and unique modular design, users may easily setup their customized Gateway. Also secondary development can be completed through AMI (Asterisk Management Interface).

There are three models with VoxStack series of 3G Gateway, the VS-GW1202, VS-GW1600 and VS-GW2120. The Modular Design of 3G Gateways are ranging from 4 up to 44 3G/UMTS channels, it is designed for multiple frequency bands Including 3G/UMTS 850/900/1900/2100 MHz, and it can support a wide selection of codecs, including G.711A, G.711U, G.729, G.722, G.726. For a reliable connecting 3G to voip gateway, it can quickly reduce telecommunication expenses and maximize cost-savings. With the unique design of the VoxStack Gateway, it can support hot-swap for both SIM cards and 3G gateway modules. Users can simply add or remove the modules for hardware expansion or exchange. Each 3G gateway module runs an independent asterisk system inside. The VoxStack gateway designs with two LAN Switch boards that provide stackability on the hardware upgrade. The 3G Gateways will be 100% compatible with asterisk, Elastix, trixbox, 3CX , FreeSWITCH SIP server and VOS VoIP operating platform.

Sample Application


Figure 1-2-1TopologicalGraph


Product Appearance

The picture below is appearance of VS-GW2120.


Figure 1-3-1 Product Appearance



Figure 1-3-2 Front Panel


0Network Data Switch Board: ETH1, ETH2. ETH1: Access Board 1 only, provide proxy access to other boards with different port numbers which can avoid IP conflict. ETH2: Access different Boards with different IP address.


VoxStack provides 2 working modes: Stand-alone and Cluster.

  • Stand-alone: A single IP address manages one 3G modules (4 ports).

Table1-3-1 ETH2 IP Addresses


Stack Num



















  • Cluster: A single IP address manages up to 5 GSM modules (up to 20 ports)
                                            Default IP:

Figure 1-3-3 Front Panel

Table 1- 3-2 LED Indicator

LED Indicator




6Signal Status LED

Green and Flash

Module Initiating

Red and Flash

No SIM Card

Red and No-flash

Worst Signal Quality

Yellow and No-flash

Medium Signal Quality


Green and No-flash

Best Signal Quality

7Call Status LED

Flash (0.25s)




89Network Status LED

(A LED indicates a board)

Green and Flash

Network Connected

10Running Status LED

Green and Flash(1s)

Work Normally

11Power LED

Always Green

Supply Power

Main Features

  • Modular and VoxStack design
  • Based on AsteriskR
  • Editable AsteriskRconfigurationfile
  •  Wide selection of codecs and signaling protocol
  • Support SMS sending, receiving, group sending
  • Support transferring SMS to E-mail
  • Support SMS automatically resent
  • Support SMS remotely controlling gateway
  • Support USSD service
  • Support IMEI modification
  • Support PIN identification
  •  Support unlimited routing rules and flexible routing settings
  •  SIM cards and modules are all hot-swap
  •  Stable performance, flexible dialing, friendly GUI

Physical Information


Table 1-5-1Description of Physical Information







GSM 850/900/1800/1900MHz


-40~85°C (Storage)

-40~85°C (Operation)

Operation humidity

10%~90% non-condensing

Max power


LAN port



Default IP:

Username: admin

Password: admin

Every VS-GWM400G is independent with each other, please enter the default IP in your browser to scan and configure the module you want. For the first time, please enter every IP to configure every module one by one. Now we offer you two ways to access to your gateway. There are two RJ45 Network ports on the board, ETH1 and ETH2. They are different. If chooseETH1, you can access Board 1 only, then access to other boards with different port numbers but the same IP address, this will helpto avoid IP conflict. If you choose ETH2, you can access different Boards with different IP addresses.

Notice: Log in 

Figure 1-6-1 LOG IN Interface


2. System


On the “Status” page, you will find all GSM, SIP, Routing, Network information and status.


Figure 2-1-1 System Status

Table 2-1-1 Description of System Status





Number of GSM ports.


Display the signal strength of in each channels of GSM.


Bit Error Rate.


Display the network carrier of current SIM card.

Registration Status

Indicates the registration status of current GSM module.


Post Dial Delay (PDD) is experienced by the originating customer as the

time from the sending of the final dialed digit to the point at which they

hear ring tone or other in-band information. Where the originating networkis required to play an announcement before completing the call then thisdefinition of PDD excludes the duration of such announcements.


The Average Call Duration (ACD) is calculated by taking the sum ofbillable seconds (bill sec) of answered calls and dividing it by the numberof these answered calls.


Answer Seizure Ratio is a measure of network quality. Its calculated by

taking the number of successfully answered calls and dividing by the total

number of calls attempted. Since busy signals and other rejections by the

called number count as call failures, the ASR value can vary depending

on user behavior.

Module Status

Show the status of port, include blank space and “READY”. Black space means it is unavailable here and “Ready” means the port is available.[a1] 

Remain Time

This value is multiplied by to step length is a rest call time.


Table 2-2-1Description of Time Settings




System Time

Your gateway system time.

Time Zone

The world time zone. Please select the one which is the same or

the closest as your city.


Posix timezone strings.

NTP Server 1

Time server domain or hostname. For example, [time.asia.apple.com].

NTP Server 2

The first reserved NTP server. For example, [time.windows.com].

NTP Server 3

The second reserved NTP server. For example, [time.nist.gov].

Auto-Sync from NTP

Whether enable automatically synchronize from NTP server or not. ON (enable), OFF (disable).

Sync from NTP

Sync time from NTP server.

Sync from Client

Sync time from local machine.


For example, you can configure like this:

Figure 2-2-1 Time Settings

You can set your gateway time Sync from NTP or Sync from Client by pressing different buttons.

Login Settings

Your gateway doesn't have administration role. All you can do here is to reset what new username and password to manage your gateway. And it has all privileges to operate your gateway. You can modify “Web Login Settings” and “SSH Login Settings”. If you have changed these settings, you don’t need to log out, just rewriting your new user name and password will be OK. Also you can specify the web server port number.


Table 2-3-1Description of Login Settings




User Name

NOTES: Your gateway doesn’t have administration role.

All you can do here is defining the username and password to manage your gateway.

And it has all privileges to operate your gateway.

User Name: Allowed characters:

"-_+. <>&0-9a-zA-Z". Length: 1-32 characters.








Allowed characters "[0-9a-zA-Z’~!@#$%^&*()_+{}-=[],./]".

Length: 4-32 characters.

Confirm Password

Please input the same password as 'Password' above.


Specify the web server port number.


Figure 2-3-1 Login Settings

Notice: Whenever you do some changes, do not forget to save your configuration.

General and Cluster

Language Settings

You can choose different languages for your system. If you want to change language, you can switch “Advanced” on, then “Download” your current language package. After that, you can modify the package with the language you need. Then upload your modified packages, “Choose File” and “Add”.


Figure 2-4-1 Language Settings

Scheduled Reboot

If switch it on, you can manage your gateway to reboot automatically as you like. There are four reboot types for you to choose, “By Day, By Week, By Month and By Running Time”.


Figure 2-4-2 Reboot Types

If use your system frequently, you can set this enable, it can helps system work more efficient.

Working Mode

OpenVox 3G Gateway offers you two ways to cluster your gateway: Automatic Cluster or Manual Cluster.

When you first time log in your gateway, you will only see 4 ports of one module. Then you can press  button, the system will search other modules in the LAN and communicate.


Figure 2-4-3 Automatic Cluster

If you want to choose Manual Cluster, you should switch Detail on first.

There are five VS-GW2120 modules which are independent with each other integrated in one 3G Gateway, so we offer 3 kinds of Working Modes. 

Figure 2-4-4 Working Modes


  • Stand-alone Mode: Run alone, total 4 ports.
  • Master Mode: Run as master with two different IP, controlling up to four slaves.

(The master can be accessed by the original IP. The target IP is used to communicate with the slaves.)

  • Slave Mode: Run as slave with two different IP, controlled by the master. If the original IP is forbidden, the slave can be accessed by the master with inward IP only.


Notice: You can choose Remain Original IP address ON or OFF. If set it on, you can log in your getaway with Original IP and Target IP.


Table 2-4-1 Definition of Master Options





Stand-alone Mode:

  Run alone total 4 ports

Master Mode:

Run as master with two different IP, controlling up to four slaves.

   The master can be accessed by the original IP. The target IP is used to   communicate with the slaves.

Slave Mode:

   Run as slave with two different IP,controlled by the master.

   If the original IP is forbidden, the slave can be accessed by the master with  inward IP only.








(master mode)

Master Mode password.

Must be 4~16bits digital 0-9.

Master IP(Local IP)

(master mode)

Master’s target IP.

Must be set in the subnet different from external subnet,

so that the external subnet couldn’t access internal subnet.

Slaves IP List

Set the slaves’s original and target IP. The original IP is outward IP, and the target IP is inward IP. Up to four slaves.


Tools and Information

On the “Tools” pages, there are reboot, update, upload, downloadand reset toolkits.

Reboot Tools

You can choose system reboot and Asterisk reboot separately.


Figure 2-5-1 Reboot Prompt

If you press “Yes”, your system will reboot and all current calls will be dropped. Asterisk Reboot is the same.

Table 2-5-1 Instruction of reboots




System Reboot 

This will turn off your gateway and then turn it back on. This

will drop all current calls.






Asterisk Reboot

This will restart Asterisk and drop all current calls.

We offer 2 kinds of update types for you, you can choose System Update or System Online Update. System Online Update is an easier way to update your system, if you choose it, you will see some information below.


Figure 2-5-2Prompt Information

If you want to update your system and remain your previous configuration, you can first backup configuration, then you can upload configuration directly. That will be very convenient for you. 

Figure 2-5-3 Upload and Download

Sometimes there is something wrong with your gateway that you don’t know how to solve it, mostly you will select factory reset. Then you just need to press a button, your gateway will be reset to the factory status.


Figure 2-5-4 Factory Reset


On the “Information” page, there shows some basic information about the 3G gateway. You can see software and hardware version, storage usage, memory usage and some help information. 

Figure 2-5-5 System Information


You can see much information about your SIM cards on this page.

Module Settings

Figure 3-1-1 Module Settings

On this page, you can see your 3G module status and click action  button to configure the port.

Figure 3-1-2 Port Configure

As you see, we have offered “Band” option, you can select different bands easily and you have many options.

If you have set your Pin Code, you can check on like this: 

Figure 3-1-4 PIN Code Application

If you want to hide your number when you call out, you can just switch CLIR “ON” (Of course you
need your operator’s support).

When you are on the phone, other calls coming in, you can set Call Waiting on, then the coming
calls won’t be hung up.
IMEI Modification
One more feature, we offer you IMEI automatically modification.

We have offered you IMEI modification function. If you want to modify your IMEI number, please
do as follows.
You can log in your gateway and modify IP address as follows. Input web site below on your
browser. http://your gatewaIp/cgi-bin/php/gsm-autoimei.php.
Then you will see the following picture. Don’t forget to switch “Enable” to “ON”, or you can’t
change your IMEI numbers.

As you can see, you can set any number you wan for every port. “X” means any digits from 0 to 9.
You just need to fill in “Set to All ”, then press “Set to All”, you can see the interface as above. Don’t
forget to press “Save”. Then “Current IMEI” will change. That means Autogeneration. If you want to
set a certain number as your IMEI, you can press “Manual”. Then you will be required to input a new IMEI.

After configuration, you can press “Back Home” to return your gateway interface.


Call Duration Limit Settings

Now we can offer you two types of call duration limit, you can choose “Single Call Duration Limit” or “Call Duration Limitation” to control your calling time.

  •  Single Call Duration Limit

This will limit the time of each call

When you make a call by this port, it will limit your calling time within the product of
Step * Single Call Duration Limitation
And if your calling time overtops the value above, the system will hang up this call.

  •  Call Duration Limitation

This will limit your total calling time of this port.


The same algorithm with single time limitation, the total calling time of this port can’t beyond the product of “Step” and “Call Duration Limitation”.

If the duration of a call is less than “Minimum Charging Time”, it will be not included in “Call Duration”.
You can set a digit for “Alarm Threshold”, when the call minutes less than this value, the gateway will send alarm info to designated phone.
You can enable your Auto Reset, then choose by day, by week, or by month.

You can save your configuration to other ports.


Call Forwarding

Sometimes it’s not convenient for you to answer a call, if you don’t want to lose some important calls, you can choose Call Forwarding. You can choose Call Forwarding Unconditional, Call
Forwarding No Reply, Call Forwarding Busy or Call Forwarding on Not Reachable. If want to cancel your call forwarding settings, you can choose Cancel All.



Call Waiting

Call Waiting is a feature that alerts you to an incoming call while you're on another call. It also lets you switch between the calls. It's automatically included with all Verizon Wireless plans.


You can do some DTMF Detection Settings if you choose “GSM -> DTMF”.

Notice: If you don’t have special need, you don’t have to modify these settings. You can just choose“Default”

  • DTMF Normal Twist and Reverse Twist is the difference in power between the row and column

         energies. Normal Twist is where the Column energy is greater than the Row energy. Reverse
         Twist is where the Row energy is greater.

  •  DTMF Relative Peak Row: The value is the smaller and the detection is easier. If you lost some

           numbers, you can try to put the value down. The adjustment range is 0.02 at a time.

  •  DTMF Relative Peak Col: The value is smaller and the detection is easier. If you lost some

          numbers, you can try to put the value down. The adjustment range is 0.1 at a time.

  •  DTMF Hits Begin: Sampling matching value. You can choose 2 or 3.
  •  DTMF Misses End: The time interval between the two digits you input. Adjust the speed of

          input. The smaller value represents the shorter intervals.


You can get USSD information, send AT command and check number with this module. When you have a debug of the GSM module, AT command is useful.



        If you want to send AT command, first you should input your command, then select certain ports and choose “Copy to Selected”, finally choose “Execute”.









VOIP Endpoints

This page shows everything about your SIP, you can see status of each SIP.



For convenience, we have designed a method that you can register your SIP endpoint to your gateway, thus your gateway just work as a server.

Also you can choose registration by “This gateway registers with the endpoint”, it’s the same with “None”, except name and password.


Table 4-1-1 Definition of SIP Options

Advanced: Registration Options


Call Settings

Advanced: Signaling Settings

Advanced: Timer Settings

Advanced SIP Settings


Advanced: NAT Settings

Parsing and Compatibility




Codec Settings

Select codecs from the list below

Table 4-3-2Instruction of Music On Hold

5. Routing

Call Routing Rule

The figure above realizes that calls from “support” SIP endpoint switch you have registered will be transferred to umts-1.1. When “Call Comes in From” is gsm, “prepend”, “prefix” and “match pattern” in “Advanced Routing Rule” are ineffective, and just “CallerID” option is available.

DISA Settings

When you make “Authentication” switch to “ON”, this page is available.

Advance Routing Rule

Figure 5-1-3 Advance Routing Rul


You can create various time routes and use these time conditions to limit some specific calls.


If you configure like this, then from January to March, from the first day to the last day of these months, from Monday to Thursday, from 00:00 to 02:00, during this time (meet all above time conditions), all calls will follow this route. And the time will synchronize with your Sever time.

You set your caller ID name and caller number as you like before sending the call to the endpoint. You can also configure forward number when you have a transfer call.


You can add one or more “Failover Call Through Numbers”.


Sometimes you want to make a call through one port, but you don’t know if it is available, so you have to check which port is free. That would be troublesome. But with our product, you don’t need to worry about it. You can combine many UMTS or SIP to groups. Then if you want to make a call, it will find available port automatically.

MNP Settings

Mobile Number Portability allows switching between mobile phone operators without changing the mobile number. Sounds simple, but there are loads of tasks performed behind the scene at the operator end.
The URL is shown in the password string way. So please type the url in other place such a txt file, check it, then copy it to the gateway. The outgoing number in the url should be replaced by the variables ${num}.
Here is an example of the MNP url:
The 8388166902 is the outgoing phone number, when config the MNP url, should replce it with  ${num}. Then it turns to

https://s1.bichara.com.br:8181/chkporta.php?user=832700&pwd=sdsfdg&tn=${num }.

6. SMS

SMS Settings


You can choose enable SMS stored and SMS status report or not. But if you want to see your SMS outbox, you should switch SMS Status Report ON.


Sender Options

You can change sender options here, include resend, times of resend


SMS to E-mail

This is a tool that makes it available for you to email account to transmit the SMS to other email boxes. The following settings realize that received SMS through openvpnvoip@gmail.com transmit to openvpnvoip@yahoo.com.cn, openvpnvoip@hotmail.com andsupport@openvox.cn.



SMS Control

Allowing endpoints to send some specific KEY WORDS and corresponding PASSWORD to operate the gateway and message is case-sensitive. In default, this function is disabled.


For example, SMS control password is 123456789 which has nothing to do with the login password, you can send “get info 123456789” to the UMTS module’s phone number to get your
gateway’s IP information.




SMS Sender

You can choose one or more ports to send SMS to the destination number, different numbers should be separated by symbols: '\r', '\n', space character, semicolon and comma. Then you can see much feedback information.


SMS Inbox

On this page, you are allowed to scan, delete, clean up, and export each port’s received SMS. Also you are allowed to check messages by port, phone number, time order and message keywords.

7. Network

On “Network” page, there are five sub-pages, “LAN Settings”, “DDNS Settings”, and “Toolkit”.

LAN Settings

There are three types of LAN port IP, Factory, Static and DHCP. Factory is the default type, and it is When you Choose LAN IPv4 type is “Factory”, this page is not editable.
A reserved IP address to access in case your gateway IP is not available. Remember to set a similar network segment with the following address of your local PC.

Basically this info is from your local network service provider, and you can fill in four DNS servers.



DDNS Settings

You can enable or disable DDNS (dynamic domain name server).



It is used to check network connectivity. Support Ping command on web GUI.

8. Advanced

Asterisk API

When you make “Enable” switch to “ON”, this page is available.


Once you set like the above figure, the host is allowed to access the gateway API. Please refer to the following figure to access the gateway API by putty. is the gateway’s IP, and 5038 is its API port.

Asterisk CLI

In this page, you are allowed to run Asterisk commands.


If you type “help” or “?” and execute it, the page will show you the executable commands.

Asterisk File Editor

On this page, you are allowed to edit and create configuration files.
Click the file to edit.


Click “New Configuration File” to create a new configuration file. After editing or creating, please reload Asterisk.

9. Logs

On the “Log Settings” page, you should set the related logs on to scan the responding logs page. For example, set “System Logs” on like the following, then you can turn to “System” page for system logs, otherwise, system logs is unavailable. And the same with other log pages.

Recently we have made our LOGS display richer, you can see your GSM Outbound of every port clearly.