# SMS Module

Bogdan
Iancu
FhG FOKUS

    		    iancu@fokus.fraunhofer.de

2003
FhG FOKUS

## Admin Guide

### Overview

This module provides a way of communication between SIP network (via SIP MESSAGE) and GSM networks (via ShortMessageService). Communication is possible from SIP to SMS and vice versa. The module provides facilities like SMS confirmation--the gateway can confirm to the SIP user if his message really reached its destination as a SMS--or multi-part messages--if a SIP messages is too long it will be split and sent as multiple SMS.

Errors occurred because of an invalid number or a too long message or because of an internal modem malfunction are reported back to the SIP user via a SIP message containing explanations regarding the error.

#### Hardware Requirements

The SMS module needs a GSM modem to be able to send/receive the SMS messages. Usually, this kind of modems are externals, linked to the machine via serial cable. The modem can be a dedicated one (as the ones provided by FALCOM) or can be a GSM telephone that has an internal modem (as the latest mobile phones from NOKIA and ERICSSON).

#### Numbering Plan

The gateway accepts and advertises phone numbers in international format, more specific like: +(international code)(area code)(number). Ex: Germany, D1 = +49 170 5678181 Romania, Connex = +40 722 123456 A number in this format is expected to be placed as username into RURI or in the To header. If RURI misses the username, the To header will be considered. Also, the gateway will advertise in this format the username in Contact headers (in SIP replies and requests) and in From headers (in SIP requests).

#### Address Mapping

To identify the destination number of the SMS, the gateway expects to have a mobile number in username of the SIP destination address (for example sip:+401704678811@iptel.org). For the reverse direction, because the gateway has only one GSM number, the destination SIP address has to be encapsulated into the SMS body. The gateway expects to find a SIP address at the beginning of the SMS body in "sip:user.host" format. Everything before the SIP address will be discarded, the useful text begins exactly after the address (for example SMS="For sip:user@host hello world!!" -> SIP="hello world"), view configuration for disable this behavior (modems parameters 's' y 't'). In order to facilitate replying, the gateway sends all the SMS messages with a header containing the source SIP address in the following format: "From sip:user@host (if you reply DONOT remove it)<new_line>". When an SMS-reply is received having this header (all of it or truncated at the end), the header will be left out (it will not be in the SIP message).

### Dependencies

The following modules must be loaded before this module:

- tm - Transaction Manager.