(string, 1 - 252 bytes) For one-way SMS, by default, the IP host name of the SMPP server to connect to is the official host name associated with the channel; that is, the host name shown on the second line of the channel’s definition in MTA’s configuration. This option may be used to specify a different host name or IP address which will override that specified in the channel definition. When specifying an IP address, use dotted decimal notation; for example, 127.0.0.1.
For two-way SMS, set to point to the host name or IP address of the SMS Gateway Server. If using the SMPP relay’s LISTEN_INTERFACE_ADDRESS option, then be sure to use the host name or IP address associated with the specified network interface address.