Common protocols - UCP/EMI

Ozeki Message Server has built in support for Universal Computer Protocol / External Machine Interface (UCP / EMI). This protocol is often used by GSM service providers for IP SMS connectivity. The currently used protocol versions (v3, v3.5, v4.0) can be used to transfer high volumes of SMS traffic.

It is used for both premium rate and normal rate SMS messages. In order to use UCP to connect to an SMSC over the internet or other private TCP/IP network, a contract should be signed with the service provider. The TCP/IP link can be a leased line or the Internet. One advantage of using UCP connections is that the client is able to specify the sender address of the message. The sender address can be a custom phone number or a short word containing alphanumeric characters. Unfortunately some GSM service providers restrict the use of this option. Another advantage of UCP is that it makes it possible to send every message type the GSM network can carry. It can be used to send binary SMS messages (operator logos, ringtones), wap push messages and other messages as well. Concatenated SMS messages and various alphabets can also be used. If you wish to use UCP to connect to your service provider, you need to get the following information from the service provider:

IP address of the SMSC
Port number of the SMSC
User name
Password

Some service providers require you to set up an IPSEC VPN tunnel when you wish to connect to their SMSC (Figure 1).

ucp connection with vpn
Figure 1 - UCP connection with VPN

In most cases you need a fix IP address, that you have to tell the provider so they can give you access through their firewall. In some situations, the service provider does not want you to be able to set up more than one UCP connections from your computer to their service. If this is the case, they might ask you to use a specific source port for the connection.

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