Data Network basics
Data network basics
Data Network basics
Data network basics
The ethernet history
- Ethernet is developed by XEROX company, (Palo Alto Research Center) in 1973 by Mr Robert Metcalfe.
Metcalfe’s law:
“The value of a network is proportional to the square of the users of the system”
After concepting ethernet Metcalfe started the 3Com company in 1979.
Data network basics
The OSI model
Layer 7 Application Contains functions for particular application services
Layer 6 Presentation Data encryption and data compression
Layer 5 Session Establishment, maintanance and termination of sessions
Layer 4 Transport Flow control and error correction
Layer 3 Network Addressing of messages and determination of routes
Layer 2 Data link Procedures and protocols for operating the communication lines
Layer 1 Physical Physical connection to network
Layer 7 Application Contains functions for particular application services
Layer 6 Presentation Data encryption and data compression
Layer 5 Session Establishment, maintanance and termination of sessions
Layer 4 Transport Flow control and error correction
Layer 3 Network Addressing of messages and determination of routes
Layer 2 Data link Procedures and protocols for operating the communication lines
Layer 1 Physical Physical connection to network
Sending host Receiving host
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Data network basics
The OSI model
Data network basics
The OSI model
Layer 7 Application Contains functions for particular application services
Layer 6 Presentation Data encryption and data compression
Layer 5 Session Establishment, maintanance and termination of sessions
Layer 4 Transport Flow control and error correction
Layer 3 Network Addressing of messages and determination of routes
Layer 2 Data link Procedures and protocols for operating the communication lines
Layer 1 Physical Physical connection to network
Data
Segment
Packet
Frame
Bits
Upper layer data
TCP header Upper layer data
IP header Data
MAC header Data FCS
100101101010100000000000
UDP header Upper layer data
Data network basics
The OSI model
Internet Aviom EtherSound CobraNet Dante
Layer 7 Application Contains functions for particular application services
HTTP
Layer 6 Presentation Data encryption and data compression
Layer 5 Session Establishment, maintanance and termination of sessions
Layer 4 Transport Flow control and error correction
TCP UDP
Layer 3 Network Addressing of messages and determination of routes
IP IP
Layer 2 Data link Procedures and protocols for operating the communication lines
Ethernet Ethernet Ethernet Ethernet
Layer 1 Physical Physical connection to network
Copper/fiber Copper Copper Copper/fiber Copper/fiber
Data network basics
The Building blocks
Data network basics
The Building blocks, the NIC
- Network Interface Card
- OSI model layer 1 connection
- Consider a regular audio device as a NIC
- Each NIC has a unique OSI Layer 2 identifier, the MAC address
Data network basics
What is a MAC address ??
- MAC = Media Access Control
- A MAC address is an OSI model Layer 2 identifier
- A MAC address is world wide unique
- ID’s are given by the IEEE Standards Association
- ID’s can be checked:
Data network basics
What is a MAC address ??
General = XX.XX.XX.XX.XX.XX
In total 2566 = 281.474.976.710.656 addresses
Yamaha = 00.A0.DE.XX.XX.XX (2563 = 16,8 million options)
00-A0-DE-25-20-0A
By the way: rearth = 1,7x106m
so Aearth = 4πr2= 3,6x1013m2
Means: 2,8x1014/3,6x1013 = 7 MAC/m2
Data network basics
The Building blocks, the HUB
- A hub is a networking distribution unit in Layer 1 of OSI
- Incoming frames are sent to all ports
Frame
Source MAC
Destination MAC
Frame
Frame
Frame
HUB
1 2
3
4
Data network basics
The Building blocks, the L2 Switch
- A switch is an intelligent networking distribution unit in Layer 2 of OSI (MAC)
- The switch stores the MAC address/port combination into a MAC addres table. The so called “translation table”
- Switches can be unmanaged or managed
- Managed switches have different extra technology build in
- VLAN
- QoS
- Redundancy
Frame
Frame
Switch
1 2
3
4
1 MAC
2 MAC
3 MAC
4 MAC
Frame
Frame
Data network basics
What is an IP address ??
- IP = internet protocol
- An IP address is an OSI model Layer 3 identifier
- Some IP addresses are worldwide unique
- Some are not (private addresses i.e. 192.168.0.1)
IP: A.B.C.D Subnet: 255.255.255.000 Class C 256 hosts
IP: A.B.C.D Subnet: 255.255.000.000 Class B 2562=65536 hosts
IP: A.B.C.D Subnet: 255.000.000.000 Class A 2563=16777216 hosts
Data network basics
What is an IP address ??
- The private IP addresses:
IP: A.B.C.D Subnet: 255.255.255.000 Class C 256 hosts
IP: A.B.C.D Subnet: 255.255.000.000 Class B 2562=65536 hosts
IP: A.B.C.D Subnet: 255.000.000.000 Class A 2563=16777216 hosts
One special Class B network is the “link local” or “fallback range”. Device set to DHCP, but no DHCP server in the network. That is the range Dante devices use by default.
10.0.0.0 – 10.255.255.255 16.777.215 Host ID’s(1x2563)
1 Class A network
172.16.0.0 – 172.31.255.255 65.535 Host ID’s(2562)
16 Class B networks
192.168.0.0 – 192.168.255.255 256 Host ID’s(2561)
256 Class C networks
169.254.0.0 – 169.254.255.255 65.535 Host ID’s(2562)
1 Class B networks
Data network basics
About subnetworks , Classless Inter Domain Routing (CIDR)
Class CIP: 192.168.10.100 11000000 . 10101000 . 00001010 . 01100100Subnet: 255.255.255.0 11111111 . 11111111 . 11111111 . 00000000
In CIDR noted as: 192.168.10.100/24 Which leaves: 32-24=8 >28=256 hosts
Class BIP: 172.18.135.12 10101100 . 00010010 . 10000111 . 00001100Subnet: 255.255.0.0 11111111 . 11111111 . 00000000 . 00000000
In CIDR noted as: 172.18.135.12/16 Which leaves: 32-16=16 >216=65536 hosts
“Supernetting”or “Classless Subnet Masks” IP: 192.168.24.12 11000000 . 10101000 . 00011000 . 00001100Subnet: 255.255.252.0 11111111 . 11111111 . 11111100 . 00000000
In CIDR noted as: 192.168.10.100/22 Which leaves: 32-22=10 >210=1024 hosts
Data network basics
The Building blocks, the router
- A router is a networking distribution unit in Layer 3 of OSI
- A router interconnects two different networks
- Internet to ethernet
- Ethernet to ethernet
- VLAN to VLAN
Router
1 280.123.100.98 192.168.10.1
Data network basics
The Building blocks, the router
- The “router” you have at home.......
ROUTER SWITCH ACCESS POINT
T
WAN
Data network basics
The Building blocks, the L3 switch
- A L3 switch is basically a L2 switch with additional L3 features
L3 switch Router 1.1.1.0/24 10.0.0.0/24 10.0.1.0/24
10.0.2.0/24
10.0.3.0/24
Data network basics
Resumé:
The NIC
The HUB
The switch
The router
The cable
Data network basics
Resumé:
The MAC address
The IP address
53°37'42.42" N 9°53'4.77" E
Siemensstrasse 22 - 34 25462 Hamburg
Deutschland
Data network basics
Ethernet topology, P2P or “ad hoc”
+ Easy and quick to setup
+ Easy to troubleshoot
- Please note to use a crosscable. (Unless the machines use auto-MDIX ports)
Audio application examples:
- Analog
- AES/EBU
- MADI
Data network basics
Ethernet topology, diasychain
+ Easy and quick to setup
+ Easy programming
+ Easy to troubleshoot
- In case of broken cable, “worm behaviour”
Audio application examples:
- EtherSound
Data network basics
Ethernet topology, Star network
+ Easy installation, expansion
+ Good performance, reliable
- High capacity star
- Star switch is s.p.o.f.
-> Use switch instead of hub, otherwise it’s bus
Audio application examples:
- Dante
- CobraNet
Data network basics
Ethernet topology, Ring network
+ Easy installation, expansion
+ Good performance, reliable
- Needs extra technology to work
Audio application examples:
- ES100
- RockNet
- Optocore
Data network basics
Ethernet topology, Mesh network
+ Self reparing, reliable
- Many connections
- Very complex
Audio application examples:
- None! Or hardly any....
Data network basics
Some building blocks which are not really relevant to audio, but interesting........
The DNS - Domain Name Server
- Translates a name into an IP address
For example: 202.55.138.123 into www.yamahaproaudio.com
- Normally given by your ISP
- Public DNS 8.8.8.8 or 8.8.4.4 (google)
Data network basics
Some building blocks which are not really relevant to audio, but interesting........
The DHCP server - Dynamic Host Configuration Protocol
- The DHCP server sends IP configuration data after it gets a request from new host
- IP address
- DNS server
- Timeserver (NTP)
- Default gateway
- etc.....
- Different DHCP modes:
- Dynamic: A range of IP addresses is defined in the DHCP.
- Static Specific IP addresses are defined based on MAC addresses.
Data network basics
Some building blocks which are not really relevant to audio, but interesting........
The Gateway - The machine in your local network that points to internet
- In most cases the gateway is the DHCP server
The Proxy - The proxyserver is an in between server that can act as a filter and request data on the clients behalf.
The firewall - A firewall regulates traffic between different networks
Data network basics
Some building blocks which are not really relevant to audio, but interesting........
WiFi
- IEEE 802.11x or WLAN
- Different protocols:
- 802.11b 2,4GHz 11Mbps
- 802.11a 5,0GHz 54Mbps
- 802.11g 2,4GHz 54Mbps
- 802.11n 2,4 and 5 GHz up to 540Mbps (finished in 2008)
- It’s not suitable for professional audio applications! (except for some very special versions)
- Very suitable for laptop running control software, iPad/iPhone, VNC
Data network basics
WiFi channels
- RF spectrum around 2.4 GHz
- Same frequency as mobile phones, bluetooth, microwave and radar
- 13 5MHz wide available channels of in Europe (US:12, Japan:14)
- Due to interference use spreaded channels.(1-13, 1-6-13, 1-5-9-13, etc)
- Use a scanner (PC: inSSIDer MAC:WiFi Explorer)
Country Channel Number
Frequency (GHz)
USA, Europe, Asia, Japan. 1 2.412USA, Europe, Asia, Japan. 2 2.417USA, Europe, Asia, Japan. 3 2.422USA, Europe, Asia, Japan. 4 2.427USA, Europe, Asia, Japan. 5 2.432USA, Europe, Asia, Japan. 6 2.437USA, Europe, Asia, Japan. 7 2.442USA, Europe, Asia, Japan. 8 2.447USA, Europe, Asia, Japan. 9 2.452USA, Europe, Asia, Japan. 10 2.572USA, Europe, Asia, Japan. 11 2.462USA, Europe, Asia, Japan. 12 2.467
Europe, Japan 13 2.472Japan 14 2.484
Data network basics
WiFi security
- Standard WiFi routers and WAP’s are not protected.
- Browser access with password
- Ecryption (WEP, WPA, WPA2)
- MAC address based filtering
- switch to stealth mode (SSID (Service Set Identifier) not broadcasted)