Introduction to IT Networking - Featuring Sabatino Castaldo from Distech Controls - Optigo Networks
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Introduction to IT Networking Featuring Sabatino Castaldo from Distech Controls May 2019
Agenda • TCP & UDP • Application • BACnet • BBMD live demo • Protocols • HTTP • VoIP • SMTP • SNMP • SSH • SFTP
Layered View (OSI & TCP/IP)
Application Layer: How is data understood
and used?
Transport Layer: How is data exchanged?
Internet Layer: How are data packets routed
from source to destination?
Network Access Layer: How are networking
devices connected together?
OSI – Traditional view focused on layers
TCP/IP – Simplified view focused on protocols
ONS-S8 and ONS-NC600
Switch Management GUI
& APIs: HTTP over TCP
ONS-C1601pi
Device Management GUI
& APIs: HTTP over TCP
ONS-YX
Network ONS-C401i
Router/core
switch
ONS-C2410p
Switch Health Status:
SNMP over TCP Device Health Status:
BACnet over UDP
ONS-YX
Optical fiber
ONS-C401i ONS-C401i
Ethernet
Transport Layer (TCP & UDP)
TCP & UDP The Transport Layer defines the level of service and status of the connection used when transporting data. The primary protocols used to facilitate this are TCP and UDP. There are many more protocols, but these are two you will most often use when working with IP-based controllers.
TCP & UDP
TCP (Transmission Control Protocol) is a standard UDP (User Datagram Protocol) a connectionless
that defines how to establish and maintain a network protocol that, like TCP, runs on top of IP networks.
conversation via which application programs can Unlike TCP, UDP provides very few error recovery
exchange data. services, offering instead a direct way to send and
receive datagrams over an IP network. It's used
n Advantages: TCP is considered a reliable primarily for broadcasting messages over a network.
transmission protocol because it re-orders
unordered segments so that they are in the right n Advantages: UDP allows for multi-cast and is
order, and it will re-send any data that gets lost in typically faster than TCP with less delay, assuming
the network. ideal network conditions.
n Disadvantages: Has significantly more overhead n Disadvantages: It’s not considered reliable since
than UDP and does not allow for “one-to-many” it does not typically make use of
messages. acknowledgements, retransmission of missing
packets, or timeouts.
Non-Networking Communications Examples
• TCP-type communication • UDP-type communication
(Air Traffic Controller to Aircraft Pilot) (Teenager to Parent)
ATC: ”This is control tower to flight 123, copy?” Teen: ”Hi I’m home!”
Pilot: “Roger tower, this is flight 123” Teen: ”OMG! You’ll never believe what happened at school
today”
ATC: “ Flight 123 please change course to 195 altitude
22,000” Teen: ”Billy’s said ‘blah blah blah…’ and I said ‘whatever’”
Pilot: “Tower, this is flight 123. You are breaking up. Please Teen: ”Then Jenny said ‘blah blah blah….’ and it was ‘totes
repeat last message” cray”
ATC: “ Flight 123, repeating, please change course to 195 ….
altitude 22,000”
Teen: ”Anyway, can I go over to Julie’s house tonight?”
Pilot: “Copy that Tower. Flight 123 changing course to
195 altitude 22,000” Parent: “Hold on, what was that?”
Teen: “You never listen to me! Can I go over to Julie’s
ATC: “Thank you flight 123, over and out”
house tonight?”
Pilot: ”Over and out, have a great day!”
Parent: “Um, I guess so?”
Application Layer
Application Layer The Application Layer provides network services to applications. This layer contains the high-level protocols many of which you have likely heard of and used.
Protocols
The Application Layer has a lot of protocols (far more than we have time to
discuss in this training). If at all possible, you should take the time to learn
about the protocols in this layer that you interact with daily.
Here are some very common protocols that are in this layer.
HTTP – Hyper Text Transfer Protocol
SNMP – Simple Network Management Protocol
SMTP – Simple Mail Transfer Protocol
NTP – Network Time Protocol
DNS – Domain Name SystemApplication Layer: Client Server vs Peer to Peer
Client Server: Peer to Peer
• Centralized server contains the useful • Data exchange between
application devices
• Website/Data base • Distributed data
• Authentication of clients • Streaming
• Remote commands • File exchange
• Request/Response based messaging • Direct or broadcast
messaging
• Pro: stable system
• Pro: cheap & easy to scale
• Con: server can be bottleneck
• Con: less control over dataBACnet
BACnet/IP
• UDP
• Peer to Peer?
• Looks like IT except for:
• Lots of broadcasts (Who-Is)
• BBMDs
• MS/TP
• No authentication or encryptionBACnet Broadcast Management Device (BBMD) To put it simply, BACnet Broadcast Management Devices (BBMDs) act as a sort of forwarding service. They’re especially useful on large, complicated networks. A BBMD forwards messages from one subnetwork to another, so communications can be broadcast locally. No overwhelming the network, and no convoluted network of one-to-one communications.
Protocols
Common Ports for Protocols • Ports are assigned to a specific application/service via configuration • This is a means to differentiate traffic by service (recall firewall discussion) • This assignment can change if you want it to (i.e. SMTP defaults to port 25 but it can assigned another port)
Hyper-Text Transfer Protocol (HTTP)
• Allows applications to define
content by mark up language
(HTML)
• Body of messages can contain a
wide range of session and
presentation layer data
• Client-server model (browser =
client, website = server)
• TCP message exchange to send
client requests and server
responses
• HTTPS – secure version
• Rest APIs – Architecture
communicates via HTTPVoice Over IP (VOIP) • Peer to peer model (some can be client < -> server < -> client) • Voice recording broken into small packets and sent to peer in “real-time” using UDP • Priority is ensuring fast communication so that conversation doesn’t get out of sync • If some packets are lost the human brain can fill in the missing data (to an extent)
Simple Mail Transfer Protocol (SMTP) • Application’s that exchange emails between users across the network • Uses TCP messaging between sender’s and recipient’s email servers • Two-way client server model (sender = client, receiver = server) • Other related protocols or extensions: POP3 & IMAP
Simple Network Management Protocol (SNMP)
• Used by network devices to provide
their status to network (BACnet of IT
world)
• Client server model where the client is
any management system needing
SNMP data and the server is the
management information base (MIB)
located on the device
• Client uses UDP message format to
request data and MIB responds
likewise
• Also can send Alarms/Traps from the
device using similar UDP messages
• Issue: unreliable – alarms/traps can be
missed!Secure SHell (SSH) • Applications used to remotely connect to and execute commands on servers • Client server application • TCP based messaging exchanges request and response • SSH has a secure session while Telnet does not • Delay is OK but need to make sure the messages are acknowledged by the remote server
Secure File Transfer Protocol (SFTP) • Transfer of encrypted files between a client and server • Uses TCP to ensure file integrity and security • More secure that the old FTP method
Thank you. Optigo Networks Inc. www.optigo.net 1-888-629-6559 1200 – 555 West Hastings St Vancouver, BC Canada, V6B 4N6
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