GoIP 4 VoIP gateway
GoIP VoIP gateways are a range of wireless gateways with 1 to 32 wirelss modules per gateway. There are models available for 2G, 3G and 4G. We tested the 2G version of the GoIP 4 with 4 wireless modem modules. GoIP gateways do not allow direct access to the individual modem modules but the gateways support the SMPP standard to be able to send and receive SMS messages and can be used with the basic- and full editions of Diafaan SMS Server.
Installation and configuration
Setting up the GoIP 4 for SMS is pretty straightforward. It uses DHCP to get an IP number from the router and, after inserting the SIM cards, has an option to receive the IP number with a phone call or an SMS message to one of the modems in the gateway. After getting the IP number, it is easy to log in to the web page of the modem to change the settings.
By default, SMPP is disabled on the GoIP gateway. The first step is to enable SMPP in the Configuration-Preferences settings of the GoIP gateway. You can set a System ID (user name) and password for SMPP or change the port number of the SMPP server.
The next step is to create a new SMPP Gateway in Diafaan SMS Server with the connection and login details of the GoIP gateway. The GoIP gateways use numeric message ID's for the SMPP messages and delivery reports do not work right away with the standard settings of the SMPP Gateway. To get delivery reports to work, the 'MessageIdFormat' property in the SMPP Gateway must be set to 'Numeric' in the settings if the new SMPP Gateway.
Sending and receiving SMS messages
The GoIP 4 only offers one SMPP connection for all the modem ports. That means that Diafaan SMS Server is not able to route the messages to the individual wireless modems. It just sends the messages to the SMPP connection and the GoIP gateway decides when the message is sent and which wireless module it uses. Received messages are sent back to Diafaan SMS Server without the phone number of the SIM card that received the message. This makes it impossible to handle messages differently depending on the phone number of the modem.
In our tests, we found a number of errors and limitations in the SMPP support of the GoIP 4. For instance, sending and receiving multi-part messages did not work. The messages were sent as multiple SMS messages and sometimes sent and/or received as empty messages. We also saw errors in the coding and decoding of the message text, so that some characters in the message were not displayed correctly.
Since we made these tests, a new hardware version of the GoIP gateway has come on the market that supports newer firmware so hopefully there are some improvements made in the SMPP handling of the latest firmware. But the version that we tested was only useful for sending and receiving basic single-part SMS messages.