VoiceBlue Next 2N GSM Gateway Configuration

VoiceBlue Next is a gateway that allows you to interface the VOIspeed SIP switchboard with GSM networks. It is available in two versions, 2 and 4 SIM, with external GSM antenna for better reception. The VoiceBlue Next Gateway is powered by a PoE system or external power supply.

Preparing the gateway for first use is quite simple:

  • Install the SIMs as shown, starting with slot 1. NOTE: Before inserting the SIMs, decide whether or not to use PIN protection. If so, set the same PIN on all SIMs.


  • Connect the antenna, screwing it to the connector;
  • Connect the LAN network cable (if PoE the device will turn on);
  • Connect the power supply (only if the PoE power supply is not used);

Warnings: always disconnect the power supply if you want to extract the SIMs or disconnect the antenna. Also, never turn on the device if it does not have the antenna connected: you could burn the GSM module.

Network Parameters and Access [Ethernet Configuration Menu]

Connect the gateway to the LAN and to the power supply if provided

  • The gateway has default IP
  • Using a browser connect to Obviously the PC used must be in the same subnet as the gateway (192.168.1.X).
  • Enter username and password. The default username is “Admin” and the password “2n”.
  • Click on “Gateway configuration” and on the subsection “Ethernet configuration”.


  • Set the desired network parameters.
    • For Cloud / UCloud platforms, the dynamic IP can be kept (Use DHCP option)
    • For the OnPremises platform, a static IP address must be set
  • Click on “Save”


If you want to leave the PIN in the SIMs, you need to configure it in the System Parameters section, but yes
must use the same PIN for all SIM cards in use, as it is not possible to specify a different one
for each system_pin

SIP Parameter Configuration [Voip Parameters Menu]

In the VoIP parameters section set the following values: Use CLIP from INVITE field: From

Deny DTMF according to RFC…: No

Forward DTMF for ME: Yes


Variant for CLOUD / UCLOUD platform

Set the following values:

Registration Expires (s): 120 (60 is often preferable)
Reattempt registration (s): 20
Registration domain: dominio_pbx
Caller ID: username gateway
Username: username authentication
Password: password gateway

Codec G.711: 2 x 10ms
Codec G.729: 2 x 10ms

The login credentials must match those set in the PBX gateway configuration. The company domain, as well as the IP address and SIP listening port for the PBX gateways can be found instead
in the configuration section of the UCloud company (see below). Eg:
= pinkinc.cluana
PBX IP address =
SIP Gateway Port = 5178
Scrolling further down in the same section check the following parameters

Codec Priority 1: G711
Codec Priority 2: G729

SIP proxy (IP->GSM): IP_PBX:port
SIP proxy (GSM->IP): IP_PBX:port
SIP registrar: IP_PBX:port

Where IP_PBX is the IP address of the VOIspeed server and port is the SIP Gateway Port seen in the previous image).


Variant for the ON PREMISES platform

The platform with stand alone server does not require registration with the gateways, therefore the configurations change as follows: in the Voip parameters section, modify the following values

Registration Domain (realm): noneCaller ID: none

SIP proxy (IP->GSM): IP_PBX:port

SIP proxy (GSM->IP): IP_PBX:port

SIP registrar:

Where IP_PBX is the IP address of the VOIspeed server and port is the SIP listening port of the PBX, by default 5060.


Security option

To prevent unwanted requests from reaching the gateway by exploiting some network flaw, you can activate the no reply on other IP addresses requests option. This setting, which allows you to accept requests for sending calls only from the IPs indicated in the SIP proxy, appreciably increases the security of the device. It is also advisable to change the default credentials for accessing the device via the web.

GSM Parameters Configuration [GSM Basic Parameters Menu]

In the GSM Basic Parameters section, set the parameters as shown in the figure (for the sake of brevity they will not be rewritten)


Group assignment [Menu GSM group assignment]

In this section the routes of incoming and outgoing calls to / from each GSM module are assigned. To use the VOIspeed standard, only one group is used, as shown in the figure. If, instead, you want to use the SIMs for different purposes, you can associate a different group to the desired SIM gsm_group_assignment gsm_group_assignment

Outgoing Group Configuration [GSM outgoing group menu]

No special configurations are to be made in this section. You can set the anonymous or clear mode for outgoing calls. Select Group 1, go down to the bottom of the page and set the CLIR parameter (restriction of the SIM number) to: Disable (Clip – on): to exit unencrypted
Enable (Clip – off): to exit anonymously
Default: according to the SIM settings

Incoming Group Configuration [GSM Incoming group menu]

This section manages the configurations for incoming calls to the gateway. In the table “Table of replaced CLIP prefixes” insert the string +39 in the Prefix field.


Set the Mode to Accept incoming calls + dialtone
Enter the value 10, in the Minimum / Maximum digits fields in DTMF (see figure below).

In some cases for short numbers it may be necessary to set the “minimum Digits” field to 9).

Set the parameter to 0: DTMF dialing timeout [s]


In the List of called numbers table, enter the company numbers with which the gateway will contact the PBX, one for each SIM and one for each row. They can be convenient numbers, but for greater clarity it is advisable to use the true number of each SIM.


Prefix configuration [Menu Prefixes]

In this section it is necessary to configure the table of prefixes accepted by the Gateway to make calls. Default count of digits: 10
In some cases, when calling shorter numbers it may be necessary to set this parameter to a different value (eg 9).Check that the table on the right contains all the digits from 0 to 9.

Time Configuration [Time Synchronization Menu]

Set the NTP server parameters: Type: Ntp
Ntp Server: it.pool.ntp.org : 123
Timezone: UTC+1Automatically switch to summer/…:
Switch to summer: last Sunday – xx.03/03
Switch to winter: last Sunday – xx.10/03 (the first digit, 25 in the figure, is irrelevant)