Ensure continued reliable operation of industrial systems that are using legacy serial (RS-232 and RS-485) modem connections and how to migrate to a future proof IP based solution. This presentation by Westermo’s Technical Director Ray Lock is an integral part of the Westermo webinar covering Serial to IP migration: https://www.westermo.com/news-and-events/webinars/serial-modem-to-ip-broadband-migration

1. Robust Industrial Data Communications – Made EasyRobust Industrial Data Communications – Made Easy
Serial to IP migration
Ensure continued reliable operation of legacy
serial (RS-232 and RS-422) modem connections
Westermo webinar
If you need instruction on how to connect audio, please visit
https://collaborationhelp.cisco.com/article/en-us/cjr7xq

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Westermo group 2019
 Founded in 1975
 Industry leading software and
hardware development force
 Own production in Sweden with
state of the art process control
 Own sales and support units in 12
key countries, distribution partners
in many others

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Presenter
Ray Lock
Technical director
Topic:
Webinar: Legacy serial (RS-232 and RS-485) modem to
IP broadband migration
Run-time:
45-60 minutes
A webinar recording will be provided after the session
is completed.

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Questions
 Ask questions in the chat window
 Ask question to ”Host”
 Questions will be answered in the end of
the presentation

5. Robust Industrial Data Communications – Made EasyRobust Industrial Data Communications – Made Easy
Serial to IP migration
Ray Lock
Network Technology Director
Westermo Group
2018, REVC

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Why a Serial to IP Webinar?
 Regulation and technology shifts are forcing change in the telecoms market
 Leased Lines are being phased out
 Dialup modems are struggling to communicate over new telecoms system
 CSD over 2G is being phased out globally
 ISDN is rapidly disappearing
 More data in near real time is becoming the norm (Big Data)
But!
 Millions of the remote devices still use serial RS-232 and modems to communicate to
the SCADA, DCS or remote maintenance.
 How can the gap in technologies be bridged without replacing the legacy equipment

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Serial to IP Webinar
Webinar aims to explain how to migrate IP broadband solutions
 Pseudo Leased lines over broadband
 How the conversion from serial to IP works
 Differences between streaming (modems) and packetised (IP)
 How ATD dialup over IP works
 Potential issue and their mitigation

8. Robust Industrial Data Communications – Made Easy
Migrating to Broadband IP

9. Robust Industrial Data Communications – Made Easy
Legacy modem’s

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Legacy Leased line
Telecom
Leased Line
Serial
RS-232
Serial
RS-232

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Legacy modem communications (Streaming)
• Analogue, ISDN and CSD 2G cellular) modems all stream serial data
10011000011110001000100010010100101111
Approx. 40-120ms
delay dependig on
modem and
modulation
Datagram
Datagram is received at the serial port
and modulated onto the carrier signal in
a continuous stream

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Legacy modem communications (Streaming)
100110000
Approx. 40-120ms
delay dependig on
modem and
modulation
Datagram
The datagram is streamed out
of the serial port after the
demodulation process
10111111110001000100010010100

13. Robust Industrial Data Communications – Made EasyRobust Industrial Data Communications – Made Easy
Leased line over IP Broadband

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Internet
Leased line replacement
Broadband network
xDSL
xDSL
SerialSerial
VPN
VPN (Virtual Private Network) becomes the leased line replacement
VPN provides a point to point link over the Internet
Encryption ensures the data remains private

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Internet
Mobile
Network
3/4G
VPN
Leased line replacement
Broadband network
VPN
(Virtual Private network)
Serial
Serial
VPN’s are media independent

16. Robust Industrial Data Communications – Made Easy
How Serial over IP works

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10011000011110001000100010010100101111
Serial to IP (Packetisation)
• Data from the sending device is buffered before sending
Serial data
Serial data is buffered
before sending

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Serial to IP (Packetisation)
• The buffered data is placed in an IP packet and sent over the network
IP Packet + serial datagram

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10011000011110001000100010010100101111
Serial to IP (Packetisation)
• The IP wrapper is stripped off and the serial datagram is replayed out the serial port

20. Robust Industrial Data Communications – Made EasyRobust Industrial Data Communications – Made Easy
Potential issue and their mitigation

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Serial over IP takes longer!
10011000011110001000100010010100101111
Serial data
10011000011110001000100010010100101111
Serial data
IP Packet + serial datagram
T1 T2 T3
Time serial data is on the wire
e.g. T1
100 bytes @9600 8,n,1 = 104ms
Total transmission time over IP broadband
including processing time will vary
depending on media in
e.g. T2 = 40ms
Replay serial data on the wire
e.g. T3
100 bytes @9600 8,n,1 = 104ms
T1 + T2 + T3 = 248ms
Between 2-6 slower than a Legacy modem connection

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Mitigating the time delay
10011000011110001000100010010100101111
Serial data
10011000011110001000100010010100101111
Serial data
IP Packet + serial datagram
T1 T2 T3
Time serial data is on the wire
e.g. T1
100 bytes @57600 8,n,1 = 17.4ms
Total transmission time over IP broadband
including processing time will vary
depending on media in
e.g. T2 = 40ms
Replay serial data on the wire
e.g. T3
100 bytes @57600 8,n,1 = 17.4ms
Speeding up the serial baud rate reduces the time on the wire
and reduces the overall delay
Total time of transmission = 74ms

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Mitigating time delays
10011000011110001000
Serial data
100010010100101111
Serial data
T1 T2 T3
Datagram = 100 bytes
Send a new IP frame after every
5 bytes
First datagram send after 5.2ms
Total transmission time over IP broadband
including processing time will vary
depending on media in
e.g. T2 = 40ms
Replay serial data starts on recite
of first IP frame 5.2ms
Largest time delay caused by buffering the whole serial message
Breaking the message into small pieces as it received and sending
over the IP connection speeds up transmission
Data now look’s like it is stream
5 bytes5 bytes5 bytes5 bytes5 bytes

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10011000011110001000100010010100101111
Mitigation using virtual serial ports
Ip connection
directly to SCADA server
Virtual serial ports
Comm 11
Comm 12
Comm 13
|
Comm 20
Comm 21
Serial data
No replay time at the receiving side IP frame is forwarded directly to the
application via the virtual serial ports

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IP Packet + serial datagram
Mitigation using virtual serial ports
IP connection
directly to SCADA server
Virtual serial ports
Comm 11
Comm 12
Comm 13
|
Comm 20
Comm 21
No replay time at the receiving side IP frame is forwarded directly to the
application via the virtual serial ports

26. Robust Industrial Data Communications – Made Easy
ATD dialup emulation

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ATD Dialup
Telecom
Dialup line
Serial
RS-232
Serial
RS-232
Call Modem
ATD 12345678
|
Exchange data
|
Close call ( ATH)
Connect 9600
Exchange data
Disconnect

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ATD Dialup emulation
Call
ATD 12345678 = 192.18.10.200
|
Exchange data
|
Close call ( ATH)
Connect 9600
Exchange data
Disconnect
ATD 12345678 = 192.168.10.200
IP address
192.168.10.200
VPN

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ATD 12345678
ATD Dialup emulation to virtual modem
IP address
192.168.10.200
VPN
Virtual modems
Modem 10
Modem 12
Modem 13
|
Modem 20
Modem 21

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ATD Dialup emulation to virtual modem
IP address
192.168.10.200
VPN
Virtual modems
Modem 10
Modem 12
Modem 13
|
Modem 20
Modem 21
Open connection

31. Robust Industrial Data Communications – Made Easy
Scaling up

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Typical utility digitisation project
Scaling up options;
• Use existing serial ports
• Install virtual serial port software
• Install virtual modem software
• Direct addressing from SCADA or DCS system

33. Robust Industrial Data Communications – Made Easy
Multiple services over VPN

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Serial and IP devices sharing connectivity
Ip connection
directly to SCADA server
10011000011110001000100010010100101111
Serial data
IP Packet + serial datagram
IP and serial devices can share the broadband/VPN connection.
IP only communications

35. Robust Industrial Data Communications – Made Easy
Increasing availability

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Increasing availability
10011000011110001000100010010100101111
Serial data
VPN
VPN
IP

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Conclusion
 Changing to IP broadband does not mean the remote devices have to change
 There are many option to replace and improve on the legacy modems
 Moving to IP broadband can increases availability
 OPEX costs can drop when moving to IP broadband connectivity

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Supporting documentation
New Whitepaper on migrating Serial to IP
Older Whitepaper on Multidrop and Leased line replacement
Numerous App notes on using serial over IP
New Webinar signup page

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Fundamentals of cybersecurity
 Network-to-Network protection
Available on website
 Best practices for using VPNs for easy network-to-network
protection
 Network segregation
Available on website
 Use WeOS switching routers to create security zones in your
network
 Defend your network from unauthorised access
17th April 2019 at 9.00 & 15.00 CET
 Learn how to secure your industrial network from
unauthorised devices and unsolicited requests using spoofing
protection and perimeter protection.

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Thank you for attending!
 An email will be sent to you including
 Playback link to Webinar recording
 Contact information to your local Westermo dealer
Next webinar: April 17th
Spoofing protection / Perimeter protection

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Robust Industrial Data
Communications – Made Easy