1. Signal strength must be adequate, and the registration obtained with the Iridium network.  On initial power up, registration normally takes about 20 to 40sec, and may vary.  Please ensure that SIM PINs are correctly entered, and are disabled if not required.  From the AT command prompt, satellite signal strength can be checked with AT+CSQ command (this command varies in response time, up to 10 seconds).  The signal is rated on a scale of 0 to 5, (5 being full signal strength, 0 being no signal).  It is recommended to have a signal strength of greater than 3 to make a call. 

2. If using a Telstra SIM, the data service must be correctly activated (by Telstra SP) to make mobile originated data calls.

3. If using a Telstra SIM the dial number is in following format:
Calling within Australia use: atd<area code><local> (e.g. atd029560xxxx).

International & within Australia use "00" or "+" <country><area><local>

To initialise the RST100 / RST200 / RST600 to receive an incoming data call, start a Terminal Program (such as HyperTerminal) with the following settings: 19200* bps, 8, N, 1, Flow Control = None.

Once connected , type the following AT commands:
ATS0=1  (This turns on auto-answer)
AT+IPR=x (where x baud of Terminal Program, according to
1 = 600 bps
2 = 1200 bps
3 = 2400 bps
4 = 4800 bps
5 = 9600 bps
6 = 19200 bps (default)
                           E.g. AT+IPR=5 sets to 9600bps Terminal rate)
AT&W0  (This stores the current (active) settings to Profile 0 of the RST100).

The device is now ready to answer an incoming data call automatically. During the waiting period, the Data RX activity timeout can expire, and Voice calls can be made (Applies only to RST100 model, with serial numbers > 10001000).

* The baud rate can be set to whatever baud rate the device answering the call is going to need and not necessarily 19.2k.  The “RING” string should be decipherable by the target device/program.

Refer to the Beam Data Guide for more information.

Call Processing is a feature of the RST100 / RST310, which only applies to VOICE calls made from the RJ11 port.  To dial data call, the full international and area codes are required, (e.g. atd00<country><area><local number>). 

After typing the dial string ATDT<number> the call LED would blink amber, but after about 5 to 10 seconds, it would extinguish, and HyperTerminal would lock up?
Answer:  This will occur if the ‘Settings - Data/SIM -Timeouts - Data RX’ (in Beam Management System (BMS) software is set to a time interval, which is shorter than the time taken for an Iridium data call to be made.  The recommended default is 40sec. 

The Data RX timer feature is functional only on RST100 units of serial numbers 10001000 and above. 
This function allows voice calls (via the RJ11 port) to be made, as well as the Comm Port to be permanently connected to a data device, which holds DTR asserted.  This timer is used to detect the absence of transmitted characters (from data device) and if greater then this period (default is 40 seconds), the RJ11 Voice port is made available to make a Voice call. 
Setting the value to 0 disables the Data RX timer.

See Beam Management System (BMS) software help for more information

You may experience difficulty when placing dial-up data calls to some parts of the world, including (but not limited to): The Middle East, Southeast Asia, China, India, Russia and Taiwan.
The end-to-end data call quality and probability of connection is governed by the ability of modems at the Iridium gateway to synchronize with modems at the termination location.  Modem synchronization is directly impacted by voice compression that is used by international telephony carriers.  International telephony carriers typically compress the analog speech, and consequently modem tones, to reduce their bandwidth requirements for carrying calls.  This compression can alter the modem tones resulting in reduced connection speeds, dropped connections, or no connections.  PSTN connection quality is not unique to Iridium data services.  The same problem would exist if you made a data call to these locations from your home computer.

To improve connection speed and reliability when dialing your ISP, it is recommended that you choose an ISP access number in the Phoenix, Arizona area if possible (area codes 602, 480 and 623) to reduce the PSTN distance between the Iridium gateway and the ISP location.  Also (and outside this area), please make sure that your ISP supports 2400 baud rate connections.

Sometimes certain file transfer protocols (such as ZMODEM) may cause the data call to end, when using an RST (100 / 200 / 310 etc) terminal.  This problem may occur when the constant stream of data is inadvertently misinterpreted as an idle timeout, in which the Terminal thinks that DTR has been de-asserted. 

Solution:
Firstly, change the data call settings to use Hardware handshaking (Hardware Flow Control) on the PC or data device. 

For RST100 / 200 / 310 : If this does not fix the problem, change the “DTR re-assert” timeout to a higher value.  Set “DTR re-assert” to 2000 (2sec) or higher for 19200 baud data call connection, or to 4000 (4 sec) or higher for 9600 baud data call connection. 

Read the Beam Management System (BMS) software help file to learn more about this setting. (“DTR re-assert” can be configured in the Beam Management System (BMS) software in the “Settings > Data/SIM >Timeouts” tab)

To install an RST unit as a modem first you must have a serial cable and an RST unit that provides a Communication Port.

Step 1:
Connect a serial cable from the serial port on the host computer to the “ComPort” on the RST system.

Step 2:
Power up the RST unit

Step 3:
In Microsoft Windows (98, ME, 2K and XP) in Control Panel, click on “Phone and Modem Options”.  Under the Modems tab click “Add”.  When the Add/Remove Hardware Wizard runs, tick “Don’t detect my modem; I will select it from a list”.  From the list displayed the correct modem to add is the “Standard 2400bps Modem”.  Click on next and select the port that the computer is using to communicate to the RST unit.  Finally click on “Finish”, the RST unit is now installed as a modem.

The RST unit can be installed as a modem on other operating systems.

Refer to the Beam Data Guide for more information.

The supervisor PIN for the RST100 / RST200 / RST310 products default as “3170”.  This PIN can be changed, and is recommended for SSAS installations, or when security is required.  The PIN can be changed on the ‘Programming - RSTx00 - Security’ tab in the Beam Management System (BMS) software nbsp; Take care in changing this code, and be sure to remember the new code.  Please advise your service provider if doing so.
It is also important to follow the procedure of changing the Security Code (from the default of 3170) on the SSAS system if installed (Programming - RST03x - Security’) so that fraudulent access is not obtain via the Beam Management System (BMS) software or Remote Commands.  HINT: Making the supervisor PIN and security codes the same will make it easier to remember, but can be made different for a higher level of security.

To configure your RST remotely you will need to know its Phone Number, and Supervisor PIN (and also the Security code if sending SSAS commands).
Remote commands are supported on RST100 and RST200 firmware 3.2 (or greater), and all RST03x firmware.

The command is constructed by using the same keyboard strokes used if you were to change the setting using the Supervisor Menu (connected to Hyper Terminal) via the Log Port @ 9600 baud.

To send a command, (without wanting a confirming reply):
Format is: RST RMT <Supervisor PIN> <command string>
Where the command string are the keyboard strokes required as if using RST menu direct in Hyper Terminal.  E.g:
    RST RMT 3170 73-9
will set the downlink audio gain to –9dB.

To send a command, that sends a return reply:
Format is: RST SMS <reply address / number> <Supervisor PIN> <command string>
E.g:    RST SMS This email address is being protected from spam bots, you need Javascript enabled to view it 3170 73-9
will set the downlink audio gain to –9dB, and return an SMS to This email address is being protected from spam bots, you need Javascript enabled to view it of the following format:

****Supv OK
73-9(233) OK
DONE

Multiple configuration commands may be sent in one SMS.
e.g. RST RMT 3170 73-9 H 743

For more information, refer to the Remote Command Guide

The fields in a "H" status is a minimised version of the "A" status.
Below is an example of both.  You will see that the fields appear in the same order.
The only exception to note is that the "UTC Time", and "RST Last Config" are not included in the H command.

Response from a "H" command:

33DegC 11.4V S5 RST100-3.6t6-D.0-10000262 POTS: 1 Hayes: 2 SLIC:2 IIC:0
E#2 None 300001001567970 SAC0307 SAC0108 SAC0200

Response from a "A" command:

Temperature: 33DegC
Input Volts: 11.4V
Signal: 5
UTC Time: 2005-02-21 22:11:22
RST100 Firmware: 3.6t6
RST PCB: D.0
RST Serial No: 10000262
RST Last Config: 2005-02-21 22:10:09
RST State: POTS: 1 Hayes: 2 SLIC:2 IIC:0
RST errors: 2
SIM MSISDN: None
LBT IMEI: 300001001567970
LBT Firmware: SAC0307 SAC0108 SAC0200

There are instances were an RST unit has gone into program mode and will not
allow the Beam Management System (BMS) software to connect to the unit to be reprogrammed. This can usually be
verified by looking at the LED’s on the front of the RST units panel. If all the
LED’s are ON then the unit is in program mode and must be reprogrammed
before any functionality will be returned.

The latest revision of the Beam Management System (BMS) software allows for reprogramming to be performed through
the GUI. Please follow the following steps:

1. Run the BMS software, ensure you are running at least version 2.0.

2. Attempt to connect to the unit. After a period it will prompt you asking if you want to reprogram the terminal; click “Yes”

3. The BMS will then display a reprogram dialog box, this screen requires
you to select the comport that the PC is using to communicate to the RST.
You will also need to know the units serial number and model type.

4. If you have an “A” in the serial number please ensure you select PCB Rev
I.0 or J.0 If you do not have an “A” in the serial number select D.0
Browse and select the required firmware for the model you are
reprogramming.

5. Click on Program once you are satisfied with the above parameters.

6. Once programming has completed it will prompt you to select either
International or Australian factory defaults.

7. Power cycle the unit, then proceed to login normally to the BMS.

NOTE: The default supervisor PIN is 3170.

 There is a known problem (acknowledged by Iridium) that when SMS messages are being delivered AND the user is simultaneously reading or replying to existing messages (via the handset), the phone may lock up.  The only way the display can be restored is by recycling power to the RST box. 
NOTE: When handset display lockup occurs, this will not affect other functionality of the RST box, and Voice calls via the RJ11 port, and also ‘Comm Port’ data calls are still possible.

The handset must be docked in its cradle in order for hands free operation to work. Leave the handset in the cradle, dial number, and begin hands free call.

To verify the software version on a 9505/A, enter *#91# on the handsets' keypad.
To verify the software version on the LBT (internal to the RST box) enter *#91# on the keypad of an Intelligent Handset.  This is also available on the Status tab of the Beam Management System (BMS) software (in the ‘LBT Firmware’ field).

Before an SBD can be sent, the LBT (in the Beam Device) must be provisioned for data. This includes Data being activated on your account and a destination address setup for the SBD to be sent to.

The destination address can be set to a specific IMEI number, an email address, or a direct IP Address / port. – Your service provider will be able to assist you in provisioning of your device.

Refer to the Beam Data Guide for more information on sending SBD's.

• Placing at least one, and up to a total of four, IMEI(s) into the subject line of the email identifies the destination ISU(s).
• o If there is more than one destination IMEIs then list the additional IMEIs on the subject line separated with a single space between each IMEI.
• White listing may be used to restrict the originator of MT-SBD messages to particular IMEIs. This restriction will fork for email and Direct IP.
• The message must contain a properly formatted sender (“From:” address), otherwise the message will be dropped by the GSS.
• The data message to the ISU must be carried as an attachment to the email:
  • The attachment name must have a ‘.sbd’ file name extension: E.g. ‘importantdata.sbd’
  • File names must be 80 characters or less. (Including the .sbd extension.)
  • File names are not case sensitive.
  • The maximum size of the binary message (not the Base64 version) is ISU specific and is between one byte and the maximum MT message size stated in Section 1.5
  • The GSS will reject message sizes that are too large for a particular ISU type.
• The attachment must use standard Multipurpose Internet Mail Extensions (MIME) Base64 encoding as defined in RFC 2045.
• Multiple messages may be queued by a single email by including the additional separate attachments in the email message, subject to the maximum number of messages permitted in the queue.
  • Note that if one of the attachments has an incorrect extension (.sbd), while others are correct then no error indication email will be sent.
  • A single email with multiple attachments creates a MT-SBD message fro each attachment. In other words – one email with ten attachments creates ten entries for the destination ISU.
• The message body plays no role in the message transfer process; any information contained in the body will be discarded.
• A maximum of 50 messages may be in any ISU’s queue at any one time regardless of whether they where sent as an individual message with attachment or a single message with multiple attachments. The GSS will reject any message over this limit.

The maximum recommended signal drop from the satellite antenna to the Iridium transceiver (either in the 9505A phone, 9505A LBT, or a Beam product) is 3dB. 
Cable: For optimal performance, we recommend using the shortest length of cable and the fewest number of connectors possible.  You must ensure that the cable used conforms to this.  An example of attenuation for RG213 cable is 0.33dB per metre @ 1.6Ghz, therefore the maximum cable length is 8m (allowing up to 0.5dB for cable interconnections).  LMR400 cable in comparison has a better attenuation figure of 0.18dB per metre.Satellite Line Of Sight: For best performance, the user’s antenna must be able to “see” the entire sky from approximately 8 degrees above the horizon. Nearby tall buildings or similar structures, heavily leafed trees, mountains, etc. can degrade performance as they block the signal between the equipment’s antenna and the satellites. Having a completely open view of the sky plays a very important role in maximizing performance, as the Iridium satellites cross the sky from horizon to horizon during a call connection.A good rule of thumb is that all surrounding obstructions should be lower than the top of a fist, which is extended at arms length, and the bottom of the fist placed on the horizon. Note that Iridium performance is immune from natural environments such as clouds, fog, rain, snow, wind and smoke.

Refer also to “Assuring Quality of Iridium Service” in the Antenna Installation Guide

All wireless devices, including satellite telephones, are susceptible to RF (Radio Frequency) interference from other electronic devices. This problem is especially evident when numerous antennas and broadcasting devices are located within close proximity to each other.

A good example would be onboard a ship. It is important that certain considerations be taken into account for best performance when an Iridium system is installed.

Causes of RF Interference:
Some subscribers have contacted Iridium regarding the loss of signal quality when they operate their equipment near active INMARSAT terminals. The power with which INMARSAT units transmit can overpower the Iridium unit’s ability to properly maintain a quality connection with the Iridium satellite constellation. INMARSAT terminals are often found in the same locations as Iridium subscribers, such as harbors, airports and especially onboard ships.

The location of the INMARSAT unit’s antenna in relation to the Iridium unit’s antenna plays a significant role in determining the degree of signal degradation that an Iridium subscriber can expect to experience. All Iridium units are susceptible to this interference, regardless of the type of antenna being used.

Generally speaking, an Iridium unit, be it a handset using its integral antenna or a fixed terminal when attached to an externally mounted antenna and located within 15 and 45 meters (50 to 150 feet, respectively) of an operating INMARSAT mini-M or Standard-C terminal, will likely experience degraded performance.

Other sources of RF interference such as Globalstar units, radar devices and broadcast stations can provide interference for Iridium units, but usually are not encountered as frequently as INMARSAT terminals.

Refer also to “Assuring Quality of Iridium Service” in the Antenna Installation Guide

Yes, this can be turned off via a range of different methods.

For more information on SIM PIN's please review the following guide

• SIM PIN Configuration guide

For more information on SIM PIN's please review the following guide

• SIM PIN Configuration guide

Dial 698698 to enter the Crew Calling platform.  Enter your PIN.  Then you are presented with 4 choices.  Enter "3" to activate the captain's PIN for voice calls only.  After you do this, you will always be prompted for a PIN when making voice calls, however you will never have to enter a PIN for data calls.

For more information on SIM PIN please review the following guide

• SIM PIN Configuration guide

For more information on SIM PIN's please review the following guide

• SIM PIN Configuration guide

The LED continues to flash when there are messages present, even if they have been read.  To stop LED flashing, messages need to be deleted.  This can be done with an Intelligent handset (or equivalent) plugged into the RJ45 port, or by using the Beam Management System software (Messages tab, click on “Clear Last SMS”).

Yes, The user must use “AT Commands", through the data port.  The AT commands use the standard GSM ‘PDU’ format

Available for download here

The Expiry Period determines how long the Iridium Service Center will attempt to deliver a message before deleting it.
• The default Expiry Period is 192 hours (8 days).
• The user can change the default Expiry Period as follows (on a Motorla / Iridium handset):
- Press the ‘Envelope’ key.
- Scroll to ‘Message Settings'. Press OK.
- Scroll to ‘Expiry Period'. Press OK.
- Enter the Expiry Period (in hours), up to a maximum of 192.
• The phone will accept any value between 1 and 24 hours in increments of one hour. Over 24 hours, the phone will round down to the nearest multiple of 24 hours (1 day increments).
• If 0 hours is entered, the expiry period will be set in the system to the default period of 192 hours (8 days).

SMS-MT messages can be sent to an Iridium phone / RST box in one of 5 ways:
- By sending an SMS-MO message from another Iridium phone.  Current limitation is 160 characters.
- By sending an SMS-MO message from a cellular phone (when available).
- By sending an e-mail to <MSISDN>@msg.iridium.com.  where <MSISDN> is the 12-digit Iridium phone number. The subject line is ignored.  “Plain Text” format is recommend for the e-mail message.
- By using the “Send a Satellite Message” feature at www.iridium.com.
- By sending an SMS-MO message from another Beam RST box, by using the Beam Management System (BMS) software messages tab.

Yes.  A user can originate an SMS message from an Iridium phone or RST device (up to 160 Characters), and send that message to another Iridium phone, to an e-mail address, or to a cellular phone (when available).
Before using SMS-MO, you must…
• Have a postpaid or demo SIM card or Prepaid and Crew Calling SIM card accounts.
• Enter the SMS Service Center Number (SMSC) into the phone / RST box, which stores the number on the SIM card. This number MUST be entered in one of these two ways: 00881662900005 or +881662900005 for an Iridium SIM, and 0061418706700 or +61418706700 for a Telstra SIM.
• Have the phone with software: ‘LAC0307’ (for 9505 Phones) and ‘SAC0307’ (for 9522 LBTs).  To verify the software version on a 9505, enter *#91# on the keypad.
• Use a SIM Card that is provisioned for SMS-MO.

Check / enter Service Center Number:
Via the handset:
. To enter the Service Center Number:
- Press the ‘Envelope’ key.
- Scroll to ‘Message Settings'. Press OK.
- Scroll to ‘Service Center'. Press OK.
. For an Iridium SIM, enter 00881662900005 or +881662900005.
. For a Telstra SIM, enter +61418706700.

Via the Beam Management System (BMS) software ):
Enter number in the “Settings - “Data/SIM” - “SIM/SMS” tab.
. For an Iridium SIM, enter 881662900005.
. For a Telstra SIM, enter 61418706700.
Click on another tab or field to commit the change in the Beam Management System (BMS) software nbsp; Please allow a few seconds for number to be displayed and changed.

Solution 1:  Recipient phone # or e-mail address entered incorrectly. Make sure phone number was entered as 00 or +, Country Code, Phone Number. Make sure e-mail was entered with a space between the e-mail address and the message.  For a Telstra SIM and Telstra SMCS, the phone number is all that is needed, e.g. 0409xxxxxx.
Solution 2: Check expiry period.  If recipient did not turn on their phone within the expiry period, message was deleted before delivery.

Below is a table showing the compatibility between Iridium and Telstra regarding SMS'

Phone calls can be made even when an alert is active.  However, the only reason that a phone call may not be able to be placed at an instance in time is if the system is in the process of sending out the Alert SMS.  This may take 10 to 30 seconds, depending on how many destinations have been set up.

If making a call on the RJ11 port (RST100), you will get a busy tone if the system is currently sending out an SMS Alert.  It's best to wait about 1 minute before trying to make a phone call directly after an Alert button has been pressed.

Alert messages are sent at a rate determined by the "Notify How Often" field in the ‘Notification’ tab in the Beam Management System (BMS) software.  The default is every 15 minutes.  If this is set to a low time (such as every 1 or 2 minutes) this will leave very little time for the system to accommodate starting a voice call, as it is too busy sending Alert SMSs.

Once an SSAS Alert has been activated (i.e. and alert button is pressed) it can be cleared in the following ways:

1. Click on “Clear Alert” in the “Alert / Monitoring” tab of the Beam Management System (BMS) software

2. By recycling the power to the RST system, or pressing the rest button of the RST03x.  For this to re-arm the SSAS, the “Alert Survives Power Loss” option must be OFF (in “Settings - SSAS - Notification” tab within the Beam Management System (BMS) software

3. By sending a remote command via SMS to the system in the following format:

RST SMS <return email/#> <Supervisor PIN> P1<Security Code> P46
an example is: RST SMS This email address is being protected from spam bots, you need Javascript enabled to view it 3170 P13170 P46

The RST system will then respond by sending an SMS to the return address (or phone number), with the following message:
****Supv OK
P13170 OK
P46 Cleared OK
DONE

The voicemail LED on the RST100 / 200 / 310 will remain flashing whilst there is an 'unread' voicemail message on the system.

To clear this and subsequently extinguish the LED from flashing, you need to do the following:

Solution: Dial the Voicemail number from a POTS handset and check the Voicemail messages.

This needs to be dialed from the POTS handset as the RST will monitor the DTMF tone of that number, and if the call is established, it will assume that the Voicemail has be listened to and extinguish the LED.

The voicemail number needs to match what is configured in the RST, and therefore is important that the correct number is set in the RST.

This can be configured with the Beam Management System (BMS) software

NOTE: Dialing the voicemail number from an Intelligent Handset will not be detected by the RST and therefore not extinguish the VM LED.

The signal LED is used to indicate the signal level, SIM status, and registration status.  The following table shows possible states of the RST after power-up:

To enable the dialed number format (when using the RJ11 port) to emulate local land line area format (i.e. so that the international and area codes do not need to be dialed), Call Processing can be enabled (using the Beam Management System (BMS) software via the Log Port), and configured for your local area codes.  Got to the ‘Settings - Analog RJ11 - Call Processing’ tab to configure.

To change the nature of the dial tone cadence, use the Beam Management System (BMS) software in the “Settings – Analog RJ11 – Line Setting – Tones – DialTone”.  Setting the Off time to 0 will set a constant dial tone.  The Unavailable (busy) tones and Ringer cadences are also configurable in this “Settings – Analog RJ11 – Line Setting – Tones” tab.

The RST100 RJ11 PSTN interface presents an analog line which emulates a normal telephone exchange line.  It supports DTMF dialing and in-call DTMF.  Dial and Busy tones are configurable. When receiving a call, the RJ11 port outputs a 56Vrms ring signal of which the frequency and pulse durations are configurable.

To connect a PBX to the RST100, an analog (PSTN) interface (e.g. a PSTN card / port (FXO)) is required for the PBX.  Simply plug in the RJ11 cable to the RST100 RJ11 analog port.  Configuration of the SL100 to access this line would be the same as if it were connected to a PSTN land line.  The impedance of the PBX port can be TN12 or 600ohm, (The "International" Factory Defaults of the RST100 set to 600ohm).
To enable the dialed number format (by the PBX) to emulate the local landline area dialing (i.e. so that the international and area codes do not need to be dialed), Call Processing can be enabled via the units configuration software and configured for your local area codes.  Got to the ‘Settings - Analog RJ11 - Call Processing’ tab to configure.

There are two main methods of setting the call forwarding options. 

1. The service provider who you purchased your simcard from can arrange to have the forwarding settings changed remotely on your account.

2. Via the serial (COMM) port on the unit you can issue “AT” commands that will change the forwarding options.  See the following extract from the Iridium AT Command reference guide.

+CCFC - Call Forward service
Exec Command:
+CCFC=<reason>,<mode>[,<number>[,<type>[,class>[,<subaddr>[,<satype>[,<time>]]]]]]
This command allows control of the call forwarding supplementary service according to GSM02.82.
Registration, erasure and status query are supported. The valid values for the parameters are as follows:
<reason> takes one of the following values:
0 unconditional
1 mobile busy
2 no reply
3 not reachable
4 all call forwarding (refer GSM 02.30)
5 all conditional call forwarding (refer GSM 02.30)
<mode> takes one of the following values:
0 disable (not used in Call Forward)
1 enable (not used in Call Forward)
2 query status
3 registration
4 erasure
<number>: string type phone number of forwarding address. It contains digits only or empty string if not
applicable.
<type>: type of address octet in integer format (refer to GSM 04.08 subclause 10.5.4.7); default 145 when
dialling string is international number, otherwise 129
<subaddr>: string type sub-address, not supported by Iridium
<satype>: type of sub-address, not supported by Iridium
<classx>: is a sum of integers each representing a class of information:
1 voice (telephony)
2 data
<time>: 1..30 when ‘no reply’ is enabled or queried, this gives the time in seconds to wait before call is
forwarded. The value of this <time> parameter is controlled by the Iridium system. No need to
specify it.
<status> :
0 not active
1 active
if <mode>=2 and command is successful, the ISU returns the following response:
+CCFC:<status>,<class>[,<number>,<type>]
Test Command: +CCFC=?
List of supported <reason>s. The response is in the form of:
+CCFC:(000-005)

Usage examples of +CCFC command
AT+CCFC=0,2,,,3 (query unconditional call forwarding for data)
+CCFC:0,1,””,255 (not active)
AT+CCFC=1,2 (query mobile busy call forwarding for voice)
+CCFC:1,1,””,255 (active)
AT+CCFC=0,3,”881631012345”,145,1 (register unconditional call forwarding of
international number for voice)
OK
Before you register for mobile busy call forwarding, you need to erase the
registration of unconditional call forwarding if it is set previously, or vise
versa.
AT+CCFC=0,4 (erasure of unconditional call forwarding for voice)
OK
AT+CCFC=1,3,”881631012345”,145,1 (register mobile busy call forwarding for
voice)
OK

Iridium AT command guide Version 2.32

Available for download here

If the RST is waiting for a SIM PIN or a PUK to be entered, an audable tone is presented to the user when the handset is lifted.

If a SIM PIN is required to be entered, the tone is an alternating High / Low tone of equal lengths. (Click here to download a sample audio file (.wav) of this tone).

If a PUK is required to be entered, the tone is alternating with a High tone for approx 2 seconds, followed by a Lower tone of approx 1 second. (Click here to download a sample audio file (.wav) of this tone).

This is a know issue found in firware versions 4.4 and earlier.

Symptom: An 'engaged' tone is heard approximately 10 seconds into a call when using a POTS handset, and will happen randomly on only some calls.

This has been addressed in firmware version 4.5 and greater.

Solution: Upgrade the RST100/310 to the latest firmware via the Beam Management System software.

Echo is influenced primarily by impedance mismatch and secondly by level setting (gains).
The RJ11 Impedance is configured via the Beam Management System (BMS) software in the “Settings – Analog RJ11 – Line Setting – Impedance” tab. 

The audio gains are configured in the “Settings – Analog RJ11 – Line Setting – Gains” tab.  Downlink meaning talk volume of other-end signal received during call, and Uplink referring to talk volume transmitted from local RST100 caller.

Uplink:
The uplink gain should normally be set to 0dB.
The major reason to modify a gain setting would be to reduce the downlink voice gain to reduce the echo fed back to the far end user. The echo is due to satellite and landlink delays and can be quite annoying.  Gains are set in +/- dB from a 0 dB reference level.

Downlink:
The downlink gain should normally be set to -9dB.
The higher the gain (more positive) is set the more likely that you will experience delayed echo from the Iridium network. The RST contains specially designed echo suppression circuitry designed by Beam to minimize the effect of this echo but care must be taken.

Impedance:
Impedance settings relate to the load the RJ11 phone presents to the RST. As the RJ11 phone line interface is a 2-wire standard, it relies on careful balancing between the impedance expected and experienced by the RST to stop signals in each direction being improperly reflected.  In normal telephone installations this is not that critical because a reflection at the far end is just experienced by the near end user as an increase in side tone (or how much you hear your own voice).
In the Iridium application, however, the echo reflected back to the far end user is delayed twice by the satellite and landline to USA delays.  By the time the user ringing the satellite phone gets to hear his voice back again it has been delayed up to a second, and this can be quite annoying.
An incorrect line impedance setting will mainly merely affect the levels, but incorrect hybrid balance impedance will directly increase the amount of echo.

Most phones will nominate the impedance on their labels and will either be 600 Ohm or TN12. TN12 impedance is mandated for any phones approved for use on the Australian network. Most phones used in US will be 600 Ohm.  Some phones are meant to be a nominated impedance but simply aren’t.  In this case choose the setting that works best and then reduce the downstream gain till the far end echo is acceptable.
The impedance can be changed (via the BMS) dynamically during a call and has an immediate effect.