2/2016
SATEL technical bulletin
SATELLAR
Serial IP is a feature where data coming from serial port is converted to IP packets and set to designated IP
address. Correspondingly the received IP packets are converted and forwarded to serial interface. Serial IP
conguration handling is divided into two sections for two interfaces:
• RS-232 connection in the radio unit (RU) and
• USB-Serial dongle attached to USB-A port of the central unit (CU)
Central Unit handles all the IP related data traic and the air interface is IP based. Central Unit is needed for
stations using the serial IP (CU, router). Central Unit is not required if the station is acting only as a repeater
(no terminal connection).
Examples
1. Point-to-point
Example “Point-to-point” presents the basic feature and usage of the conguration parameters.
Two user devices, DTE A and B are connected to SATELLARs via serial port connection and the SATELLARs are
congured to have a radio connection.
SA00060
SATELLAR B
(RU+CU)
Tun0 IP 10.10.32.2
SATELLAR A
(RU+CU)
Tun0 IP 10.10.32.1
User device
DTE B
User device
DTE A
TD
RD
PWR
STAT
RX
TX
CTS
RTS
USB
ETH
PWR
STAT
OK
TD
RD
PWR
STAT
RX
TX
CTS
RTS
USB
ETH
PWR
STAT
OK
Point-to-point example
SATELLAR A is having Tun0 IP 10.10.32.1 and SATELLAR B Tun0 IP 10.10.32.2 (can be obtained from screen
saver or from Routing – IP category). SATELLAR B is a client which is the side that initiates the connection.
It has been congured to listen messages from serial port and to send them to target address and port.
SATELLAR A is a server side that has been congured to listen dedicated IP port and to forward messages to
serial port. Transmission is always started from client side; it creates the connection between the SATELLARs.
There are some dierences for this when using UDP (See chapter 5. UDP).
How to convert data from serial port to IP packets
SATEL technical bulletin
SATELLAR
2
First, the serial port in both SATELLARs must be congured to match the User device conguration. Aer this
the SATELLARs are able to communicate with each others.
The basic idea is to cross-congure SATELLARs to communicate with each other. Protocol can be also UDP as
long as it is same in both ends.
2. TCP Server
SATELLAR is congured to listen the dened IP Port number and forward data from the port to the serial port
(IP to Serial-conversion).
SA00061
SATELLAR B
(RU+CU)
SATELLAR A
(RU+CU)
User device
DTE B
User device
DTE A
TD
RD
PWR
STAT
RX
TX
CTS
RTS
USB
ETH
PWR
STAT
OK
TD
RD
PWR
STAT
RX
TX
CTS
RTS
USB
ETH
PWR
STAT
OK
Internet
TCP Server, conversion from IP to serial port
DTE A
Ethernet IP Address 192.168.1.1
IP Route 192.168.2.0/24 via 192.168.1.2
Application able to send messages to dedicated
address and port congured to send to 192.168.2.10
port 2006
SATELLAR A
Ethernet IP Address 192.168.1.2
RMAC 1 i.e. Tun0 10.10.32.1
Packet Route to 2
IP Route 192.168.2.0/24 via 10.10.32.2
SATELLAR B
Ethernet IP Address 192.168.2.10
RMAC 2 i.e. Tun0 10.10.32.2
Packet Route to 1
IP Route 192.168.1.0/24 via 10.10.32.1
Serial IP conguration as above
Serial port conguration in line with User device DTE
B
DTE B
Serial port conguration in line with SATELLAR B
User Device DTE A has an Ethernet IP address 192.168.1.1. SATELLAR B has two IP addresses Tun0 10.10.32.2
and Eth0 192.168.2.10 which both can be used depending on the routing conguration in User device DTE A.
Ethernet address is used in this example.
Parameter SATELLAR A SATELLAR B
Mode Server Client
Protocol TCP TCP
Listening Port 2005 Irrelevant in this mode
Sending Port Irrelevant in this mode 2005
Sender Target Address 10.10.32.2 10.10.32.1
SATEL technical bulletin
SATELLAR
3
SATELLAR A does not have any Serial IP connection and it is congured to have a radio connection with
SATELLAR B. User device DTE A must be set to route messages to SATELLAR B via SATELLAR A. In this case
SATELLAR A has an IP 192.168.1.2. User device DTE A must have a route 192.168.2.0/24 via 192.168.1.2 and
must also have an application able to send messages to dedicated address and port, in this case to port 2006
at 192.168.2.10
3. TCP Client
In TCP client case whenever data comes from the serial port, the data is buered and sent to target address.
This can be e.g. some on-demand service sending some e.g. log data whenever there is something to be sent.
Setup is similar to the TCP server case.
SA00061
SATELLAR B
(RU+CU)
SATELLAR A
(RU+CU)
User device
DTE B
User device
DTE A
TD
RD
PWR
STAT
RX
TX
CTS
RTS
USB
ETH
PWR
STAT
OK
TD
RD
PWR
STAT
RX
TX
CTS
RTS
USB
ETH
PWR
STAT
OK
Internet
TCP Client
DTE A:
IP address 192.168.1.1
SATELLAR A:
IP address 192.168.1.2
SATELLAR B:
IP address 192.168.2.10
User Device DTE A has IP address: 192.168.1.1, SATELLAR A: 192.168.1.2 and SATELLAR B: 192.168.2.10.
SATELLARs are congured to have a radio connection, and IP routes are congured so that devices are able
to communicate with each other, i.e. route from User device DTE A to SATELLAR B via SATELLAR A, and from
SATELLAR B to User device DTE A via SATELLAR A.
User device DTE A must have an application that opens port listening to messages coming from SATELLAR
B. SATELLAR A does not have any Serial IP conguration. SATELLAR B has following serial port conguration,
where it is assumed that User Device DTE A has port 2005 open:
Parameter SATELLAR B
Mode Server
Protocol TCP
Listening Port 2006
SATEL technical bulletin
SATELLAR
4
4. Multipoint-to-point
Multipoint-to-point case can be presented as an extended case of TCP Client.
SA00062
SATELLAR D
TCP Port 2010
SATELLAR A
User device
DTE C
User device
DTE A
IP address:
19.21.68.10
TD
RD
PWR
STAT
RX
TX
CTS
RTS
USB
ETH
PWR
STAT
OK
SATELLAR B
TCP Port 2005
User device
DTE B
TD
RD
PWR
STAT
RX
TX
CTS
RTS
USB
ETH
PWR
STAT
OK
IP Connection
TD
RD
PWR
STAT
RX
TX
CTS
RTS
USB
ETH
PWR
STAT
OK
TCP Port 2010
TCP Port 2005
In this example the User device DTE A is capable simultaneously listen several ports. Both SATELLAR B and
SATELLAR C are congured to send the messages to User device DTE A, but to dierent ports. Following
conguration is set to SATELLAR B and SATELLAR D, when User device DTE A has IP address 192.168.1.1:
Parameter SATELLAR B
Mode Client
Protocol TCP
Sending Port 2005
Sender Target Address 192.168.1.1
Parameter SATELLAR B SATELLAR C
Mode Client Client
Protocol TCP TCP
Sending Port 2005 2010
Sender Target Address 192.168.1.1 192.168.1.1
SATEL technical bulletin
SATELLAR
5
One option for this kind of tasking is serial port virtualizing that can be done e.g. with HW VSP application:
http://www.hw-group.com/products/hw_vsp/index_en.html
The application creates virtual serial ports which are actually IP addresses and ports i.e. user denes IP
address and port combination which then creates a (virtual) serial port to system. By this way dierent
applications can use these connections as serial ports although they are actually IP connections.
5. UDP
UDP mode can be used similar to TCP modes with some extension.
In point-to-point case the mode of the device can be either client or server. Due to the nature of the protocol
both devices need to be able to send and receive independently from the other device. See chapter 7.4.3
UDP and TCP protocols (in SATELLAR Digital system part III: radio unit) for more detailed protocol explanation.
When using UDP in the Server mode in generally and some replies are needed to be sent, also the target
address needs to be set. This concerns also the Client mode and listening of replies.
Parameter SATELLAR A SATELLAR B
Mode Server Server
Protocol TCP TCP
Listening Port 2005 2006
Sending Port 2006 2005
Sender Target Address 10.10.32.2 10.10.32.1
Parameter SATELLAR B
Mode Server
Protocol UDP
Listening Port 2006
Sending Port 2005
Sender Target Address 192.168.1.1
SATEL technical bulletin
SATELLAR
6
6. Send or receive only
These features are limited versions of the presented features. The example is similar to point-to-point.
SA00060
SATELLAR B
(RU+CU)
Tun0 IP 10.10.32.2
SATELLAR A
(RU+CU)
Tun0 IP 10.10.32.1
User device
DTE B
User device
DTE A
TD
RD
PWR
STAT
RX
TX
CTS
RTS
USB
ETH
PWR
STAT
OK
TD
RD
PWR
STAT
RX
TX
CTS
RTS
USB
ETH
PWR
STAT
OK
SATELLAR A is having Tun0 IP 10.10.32.1 and SATELLAR B Tun0 IP 10.10.32.2. SATELLAR A is congured to
send to SATELLAR B and SATELLAR B is congured to listen the dened port.
The User device DTE A can only send and the User device DTE B can only listen the messages.
Parameter SATELLAR A SATELLAR B
Mode Send only Receive only
Protocol UDP UDP
Listening Port Irrelevant in this mode 2006
Sending Port 2006 Irrelevant in this mode
Sender Target Address 10.10.32.2 Irrelevant in this mode
