-
Broadband in data can refer to broadband networks or broadband
Internet and may have the same meaning as above, so that data
transmission over a fiber optic cable would be referred to as
broadband as compared to a telephone modem operating at 56,000 bits
per second. However, a worldwide standard for what level of
bandwidth and network speeds actually constitute Broadband have not
been determined.[1]However, broadband in data communications is
frequently used in a more technical sense to refer to data
transmission where multiple pieces of data are sent simultaneously
to increase the effective rate of transmission, regardless of data
signaling rate. In network engineering this term is used for
methods where two or more signals share a medium.[2] Broadband
Internet access, often shortened to just broadband, is a high data
rate Internet accesstypically contrasted with dial-up access using
a 56k modem.Dial-up modems are limited to a bitrate of less than 56
kbit/s (kilobits per second) and require the full use of a
telephone linewhereas broadband technologies supply more than
double this rate and generally without disrupting telephone
use.
-
Specific OutcomesDifferentiate between open and proprietary
protocolsProvide and overview of TCP/IP and its various
componentsExplain how and why the different Classes of IP addresses
are allocated / managedDemonstrate how a Class B IP address may be
subnetted and explain why this may be desirableExplain how an IP
packet is routed across several routersCompare and contrast IP
routing to Ethernet switchingProtocols focusing on TCP/IP
-
Protocol Types
-
Protocols and Data Transmission
NetBEUINetBEUIRouterNon-Routable
-
Types of Data Transmission
-
Common ProtocolsTransmission Control Protocol/Internet Protocol
(TCP/IP)Internetwork Packet Exchange/Sequenced Packet Exchange
(IPX/SPX)NetBIOS Enhanced User Interface (NetBEUI)AppleTalk
-
Routed Protocols (TCP/IP) Segment 1Segment 2TCP/IPTCP/IPWindows
ClientWindows Client
-
Routed Protocols (IPX/SPX) Segment 1Segment
2IPX/SPXIPX/SPXNetWare ClientWindows 2000Server
-
NetBeui
-
Appletalk
-
TCP/IPThe Communication ProcessTCP/IP LayersIdentifying
Applications
-
Communication Process
-
TCP/IP Layers
-
TCP/IP Protocol SuiteTransmission Control Protocol (TCP)User
Datagram Protocol (UDP)Internet Protocol (IP)Internet Control
Message Protocol (ICMP)Internet Group Management Protocol
(IGMP)Address Resolution Protocol (ARP)TCP/IP Utilities
-
TCP
-
UDP
-
IP
-
ICMP
-
IGMP
-
ARP
-
Diagnostic UtilitiesConnectivity
UtilitiesServer-basedSoftwareTCP/IP Printing ServiceInternet
InformationServicesTCP/IP Utilities
-
Data Flow
-
IPRouting
-
Data Transfer Across Routers
-
wxyzClass ANetwork IDHost IDClass BNetwork IDHost IDClass
CNetwork IDHost IDDifferent Classes of Addresses
-
Decimal to Binary Representation
-
Different Class of AddressClass A Net.Node.Node.Node Leading bit
= 0, Max: 126 Networks and 16777214 NodesClass B Net.Net.Node.Node
Leading bit = 10 Max 16384 Networks and 65534 Nodes (Note network
decimal range from 128 191)Class C Net.Net.Net.Node Leading bit =
110 Max 2097152 Networks and 254 Nodes (Note network decimal from
192 223)127 is reserved for loopback test: 127.0.0.1
-
Different Class of Address
Address ClassNetwork BitsHosts BitsDecimal Address RangeClass A8
bits24 bits1-126Class B16 bits16 bits128-191Class C24 bits8
bits192-223
-
Leading bits of network addressClass A NetworkClass C
NetworkClass B NetworkLeading bit is always zero (0)Leading bit is
always one and zero (10)Leading bit is always one, one zero
(110)RouterIncoming packet destined for network 01010111 (87), the
router only has to read the first bit to know which of its three
routes to forward it on
-
SubnetsSubnet Masks Determining Local and Remote HostsSubnet
Masks
-
Subnetting and Routers
-
Determining Local and Remote Hosts
-
Subdividing a Network
-
Step 1:Determine how many network IDs are required?How many
subnets will I need?Unique network ID is required for:Each
subnetEvery wide area network (WAN) connection
Subnetting Process
-
Subdividing a Network
-
Step 2:What are the maximum number of host IDs youll need on
each subnet?Each TCP/IP computer interface cardEach TCP/IP printer
network interfaceEach router interface on each subnet. If router
connected to two subnets; the router requires two host IDs two IP
addresses (see next diagram)Sub-netting Process
-
Subdividing a Network
-
Decimal to BinaryQuick class exercise: (3 minutes)Take
167.20.16.1 and work out the binary equivalent
-
Decimal to BinaryAnswer in progress: 2 2 2 2 2 2 2 2 1 0 1 0 0 1
1 1 __________________________________________________ 128 + 0 + 32
+ 0 + 0 + 4 + 2 + 1 = 167IP Address: 10100111
76543210
-
Decimal to BinaryAnswer:16720 16 1IP Address: 10100111 00010100
00010000 00000001
-
Decimal to BinaryNow add Subnet Mask: 255.255.0.0 (or class B)
16720 16 1IP Address: 10100111 00010100 00010000 00000001Subnet
Mask:11111111 11111111 (00000000 00000000)AND the two
numbers:10100111 00010100
-
Decimal to BinaryNow add Subnet Mask: 255.255.0.0 (or class B)
16720 16 1IP Address: 10100111 00010100 00010000 00000001Subnet
Mask:11111111 11111111 (00000000 00000000)AND the two
numbers:10100111 00010100Interested in this part:Network PortionNot
concerned with this part
-
Step 3:Consider host 167.20.16.1 with subnet mask 255.255.0.0
(class B) such as Rhodes UniversityIP Address: 10100111 00010100
00010000 00000001Subnet mask: 11111111 11111111 00000000
00000000Network ID: 10100111 00010100Remember that subnet mask 1
bits correspond to network ID bit in the IP address.
Subnetting Process
-
Step 3: (contd)We decide to add some bits to the subnet mask,
increasing the bits available for the network ID and thus create a
few more network combinationsNote new subnet mask is:11111111
11111111 11100000 00000000Note because of the 3 extra bits, we have
8 different network IDs.Network IDs10100111 00010100 000(167.20.0)
10100111 00010100 001 (167.20.32)10100111 00010100 010(167.20.64)
10100111 00010100 011 (167.20.96)10100111 00010100 100(167.20.128)
10100111 00010100 101 (167.20.160)10100111 00010100 110(167.20.192)
10100111 00010100 111 (167.20.224)
Subnetting Process
-
To summarize the preceding example using decimal notation:By
applying the subnet mask of 255.255.224.0 to network ID 167.20, you
create 8 new network Ids: (167.20.0, 167.20.32, 167.20.64,
167.20.96, 167.20.128, 167.20.160, 167.20.192, 167.20.224)Note: If
you used only two instead of three additional bits in the subnet
mask,We would only have four subnetsIn the case of two additional
bits, the network IDs would be10100111 00010100 00
(167.20.0)10100111 00010100 01 (167.20.64)10100111 00010100 10
(167.20.128)10100111 00010100 11 (167.20.192)Therefore we must
always use enough additional bits in the subnet mask to create the
desired numbers of subnets, though still allow for enough hosts on
each subnet.
-
Lets look at Rhodes UniversityRhodes has a scarce Class B
Internet Address (privilege)Rhodes Unique IP address is:146.231
therefore all IP addresses at Rhodes will have the network
component of 146.231The default Class B subnet mask is:255.255 or
in binary 11111111 . 11111111Rhodes can have up to 65,534 hosts if
they do not divide or steal some of these host bits, to divide the
network up into subnets.Rhodes definitely does not need to cater
for 65,534 hosts therefore the decision to divide up the network
into different subnets, for all the previously discussed
reasons.
-
Rhodes continuedRhodes administrators decide to allocate 5 host
bits to divide up the University network into subnets.11111111 .
11111111 . 11111000 . 00000000How many subnets does this give the
University?2 to the power of 5 = 32 therefore Rhodes can have up to
32 subnets.How many hosts can Rhodes have on each subnet?2 to the
power of 11 (-2) = 2,046What is the Rhodes Subnet Mask255 . 255 .
248 . 0
-
Rhodes continuedWhat are the subnets that are created?Calculated
manually, list all the combos of the additional bits0000000100
etcetc
00001.3200100etcetc00010.6400101etcetc00011.9600101etcetc00100.128xxxxxetcetc00101.160xxxxxetcetc00110.192xxxxxetc(Very
tedious)00111 etcxxxxxetc
-
Rhodes continuedWhat are the subnets that are created?A shorter,
less tedious methodList the additional octet added to the default
subnet mask in decimal notation.Convert the rightmost 1 bit of this
value to decimal notation, which is the incremental value of each
subnet value known as DeltaAppend Delta to the original ID to give
the first subnet network IDRepeat previous step for each subnet
network ID, incrementing each successive value by Delta
-
Rhodes continuedRhodes was assigned a class B network of
:146.231.0.0We created 32 subnets by taking 5 bits from the host
portion (11111000) and the rightmost bit converted to decimal is 8,
thus the incremental value is 8There are 2 to the power of 5
subnets created or 32 subnets.The subnets created
are:146.231.0146.231.8146.231.56146.231.104146.231.152146.231.200146.231.16146.231.64146.231.112146.231.160146.231.208146.231.24146.231.72146.231.120146.231.168146.231.216146.231.32146.231.80146.231.128146.231.176146.231.224146.231.40146.231.88146.231.136146.231.184146.231.232146.231.48146.231.96146.231.144146.231.192146.231.240146.231.248
-
Rhodes continuedWhat are the host IDs that we can use?
SubnetFirst IP AddressLast IP
Address146.231.0.0146.231.0.1146.231.7.254146.231.8.0146.231.8.1146.231.15.254146.231.16.0146.231.16.1146.231.23.254146.231.24.0146.231.24.1146.231.31.254146.231.32.0146.231.32.1146.231.39.254146.231.40.0146.231.40.1146.231.47.254146.231.48.0146.231.48.1146.231.55.254146.231.56.0146.231.56.1146.231.63.254UP
to 248
-
RoutingSubnet172.30.20.xSubnet172.30.21.xEthernetSwitch 2Server
Y172.30.21.86D1-Router E172.30.21.2E1-Router F172.30.21.1F1-Router
D172.30.20.1C1-Client PC R172.30.20.47A1-Server
X172.30.20.19B1-EthernetSwitch 1Router B connects to 4 subnets via
its 4 interfaces (ports)Router ARouter CRouter B
-
RoutingRouter ARouter CRouter BInterface 1Subnet
172.30.19.x802.11Interface
4172.30.19.111-Subnet172.30.20.xSubnet172.30.21.xRouter
BEthernetSwitch 2Server Y172.30.21.86D1-Router
E172.30.21.2E1-Router F172.30.21.1F1-Router D172.30.20.1C1-Client
PC R172.30.20.47A1-Server X172.30.20.19B1-EthernetSwitch 1Router Bs
Interface 1is connected to a point-to-point 802.11
subnet,172.30.19.x
This subnet goes to Router As Interface 4,which has IP address
172.30.19.1and MAC address 11-
Each interface on a router has a differentIP address and data
link layer address.
-
Router ARouter CRouter BInterface 4Subnet
172.30.22.x802.11Subnet172.30.20.xSubnet172.30.21.xRouter
BInterface 1172.30.22.921-EthernetSwitch 2Server
Y172.30.21.86D1-Router E172.30.21.2E1-Router F172.30.21.1F1-Router
D172.30.20.1C1-Client PC R172.30.20.47A1-Server
X172.30.20.19B1-EthernetSwitch 1Router Bs interface 4 also
connectsTo an 802.11 point-to-point subnet,172.30.22.x.
This reaches Interface 1 on Router C.This interface hasIP
address 172.30.22.9and MAC address 21- Routing
-
Router ARouter CSubnet172.30.20.xSubnet172.30.21.xRouter BRouter
BInterface 2EthernetEthernetSwitch 2Server Y172.30.21.86D1-Router
E172.30.21.2E1-Router F172.30.21.1F1-Router D172.30.20.1C1-Client
PC R172.30.20.47A1-Server X172.30.20.19B1-EthernetSwitch 1Router Bs
Interface 2connects to Ethernet subnet172.30.20.x.
This subnet has a single switch.
Other devices on the subnetinclude a single router (D),a single
Client PC (R),and a single server (X).Routing
-
Router ARouter CSubnet172.30.20.xSubnet172.30.21.xRouter BRouter
B Interface 3EthernetEthernetSwitch 2Server Y172.30.21.86D1-Router
E172.30.21.2E1-Router F172.30.21.1F1-Router D172.30.20.1C1-Client
PC R172.30.20.47A1-Server X172.30.20.19B1-EthernetSwitch 1Router Bs
Interface 3connects to Ethernet Subnet130.30.21.x
This subnet hasone server (Y)and two routers (E and
F)Routing
-
Router ARouter
CArrivingPacketSubnet172.30.20.xSubnet172.30.21.xRouter
BEthernetSwitch 2Server Y172.30.21.86D1-Router
E172.30.21.2E1-Router F172.30.21.1F1-Router D172.30.20.1C1-Client
PC R172.30.20.47A1-Server X172.30.20.19B1-EthernetSwitch 1A packet
arrives in Interface 1 of Router B.The router will forward the
packet out a different interface.Routing
-
Router ARouter CSubnet172.30.20.xSubnet172.30.21.xRouter BRouter
B Interface 3EthernetInterface 1172.30.22.921-EthernetSwitch
2Server Y172.30.21.86D1-Router E172.30.21.2E1-Router
F172.30.21.1F1-Router D172.30.20.1C1-Client PC
R172.30.20.47A1-Server X172.30.20.19B1-EthernetSwitch 1Here the
packet issent out Interface 3,which connects toSubnet
172.30.21.x
It must be sent toServer Y,Router E, orRouter F.Routing
-
Router ARouter CSubnet172.30.20.xSubnet172.30.21.xRouter BRouter
B Interface 3EthernetInterface 1172.30.22.921-EthernetSwitch
2Server Y172.30.21.86D1-Router E172.30.21.2E1-Router
F172.30.21.1F1-Router D172.30.20.1C1-Client PC
R172.30.20.47A1-Server X172.30.20.19B1-EthernetSwitch 1For a packet
going toServer Y,
The destination IP addressis 172.30.21.86(Server Y, the
destination host)
The packet is put in a frame withDestination MAC address
D1-(Server Y)Routing
-
Router ARouter CSubnet172.30.20.xSubnet172.30.21.xRouter BRouter
B Interface 3EthernetInterface 1172.30.22.921-EthernetSwitch
2Server Y172.30.21.86D1-Router E172.30.21.2E1-Router
F172.30.21.1F1-Router D172.30.20.1C1-Client PC
R172.30.20.47A1-Server X172.30.20.19B1-EthernetSwitch 1For a packet
going toRouter E, which willtake responsibility for the packet.
The destination IP addressis the IP address ofthe destination
host.
The packet is put in a frame withdestination MAC address
E1-(Router E).Routing
-
EthernetLAN 2Site AUnixServerOld NetWareServerInternalRouter
YSite BMultiprotocolRouter XEdgeRouter
ZTheInternetWWWServerEthernetLAN
3TCP/IPSNATCP/IPIPX/SPXMainframeEthernetLAN 1Most firms have a mix
of internetworkingarchitectures (TCP/IP, IPX/SPX, SNA, etc.).
Consequently, most routers are multiprotocolrouters that route
the packets ofmultiple architectures.Routing
-
Ethernet Switching Versus IP RoutingSwitching Table Switch
1PortStation2A1-44-D5-1F-AA-4C7B2-CD-13-5B-E4-655C3-2D-55-3B-A9-4F5D4-47-55-C4-B6-9F5E5-BB-47-21-D3-56
EthernetSwitchingSwitch 2Switch 1Port 5 on Switch 1to Port 3 on
Switch 2A1-44-D5-1F-AA-4CSwitch 1, Port 2B2-CD-13-5B-E4-65Switch 1,
Port 7Port 7 on Switch 2to Port 4 on Switch 3Ethernet switching is
fast and therefore inexpensive.For a destination MAC address,there
is only one match in the table.This can be found quickly.The frame
is sent out the port listed in that row.
-
Ethernet Switching Versus IP Routing, ContinuedIP Routing Table
Router
AInterfaceNetwork160.x.x.x2128.171.x.x1123.x.x.x260.x.x.x2123.x.x.xIP
RoutingNetwork60.x.x.xRouter CRouter BRouter
AInterface1Interface2Router topologies are meshes.This gives
alternative routes.A destination IP address willMatch multiple
rows.
-
Ethernet Switching Versus IP Routing, ContinuedIP Routing Table
Router
AInterfaceNetwork160.x.x.x2128.171.x.x1123.x.x.x260.x.x.x2123.x.x.xIP
RoutingNetwork60.x.x.xRouter CRouter BRouter
AInterface1Interface2All matching rows must be found.Then, the best
match must be found.This is slow and therefore expensive.
-
Ethernet Switching Versus IP Routing, ContinuedEthernet (and
most other) switching is inexpensive for a given traffic
volumeRouter routing is expensive for a given traffic volumeNetwork
administrators say Switch where you can; route where you must.
-
Routing TableRowDestinationNetwork orSubnetMask
(/Prefix)Metric(Cost)Next-HopRouterInterface1128.171.0.0255.255.0.0
(/16)47G22172.30.33.0255.255.255.0
(/24)0Local13192.168.6.0255.255.255.0 (/24)12G2Routers Base Routing
Decisions on Their Routing Tables.Each Row Represents a Route to a
Network or SubnetFor Each Arriving Packet, The Packets Destination
IP Address Is Matched Against the Destination Network or Subnet
Field in Every Row
-
Routing Table, ContinuedRowDestinationNetwork orSubnetMask
(/Prefix)Metric(Cost)Next-HopRouterInterface1128.171.0.0255.255.0.0
(/16)47G22172.30.33.0255.255.255.0
(/24)0Local13192.168.6.0255.255.255.0 (/24)12G2Each Row Represents
a Route to a Network or Subnet.All packets to that network or
subnet are governed by that one row.So there is one rule for a
range of IP addresses. This reduces the number of rows that must be
considered.
-
Masking1. Basic ProcessInformation bit 1 0 1 0Mask bit 1 1 0
0Result 1 0 0 0
3. Example 1IP Address172. 30. 22. 7Mask255. 0. 0. 0 Result172.
0. 0. 02. Common PatternsBinaryDecimal00000000011111111255
4. Example 2IP Address172. 30. 22. 7Mask255. 255. 0. 0
Result172. 30. 0. 0
-
Routing Table, ContinuedRow 1If Destination IP Address = 172.
30.33.6Mask = 255.255. 0.0Result = 172. 30. 0.0Destination Network
or Subnet = 128.171. 0.0No match!RowDestinationNetwork orSubnetMask
(/Prefix)Metric(Cost)Next-HopRouterInterface1128.171.0.0255.255.0.0
(/16)47G22172.30.33.0255.255.255.0
(/24)0Local13192.168.6.0255.255.255.0 (/24)12G2
-
Routing Table, ContinuedRowDestinationNetwork orSubnetMask
(/Prefix)Metric(Cost)Next-HopRouterInterface1128.171.0.0255.255.0.0
(/16)47G22172.30.33.0255.255.255.0
(/24)0Local13192.168.6.0255.255.255.0 (/24)12G2Row 2If Destination
IP Address = 172. 30. 33.6Mask = 255.255.255.0Result = 172. 30.
33.0Destination Network or Subnet = 172. 30. 33.0This row is a
match!
-
Routing Table, ContinuedRowDestinationNetwork orSubnetMask
(/Prefix)Metric(Cost)Next-HopRouterInterface1128.171.0.0255.255.0.0
(/16)47G22172.30.33.0255.255.255.0
(/24)0Local13192.168.6.0255.255.255.0 (/24)12G2Row 3If Destination
IP Address = 172. 30. 33.6Mask = Result = Destination Network or
Subnet = Is this row is a match?
-
RoutingFor Each Incoming IP PacketDestination IP address is
matched against every row in the routing table.If the routing table
has 10,000 rows, 10,000 comparisons will be made for each
packet.There can be multiple matching rows for a destination IP
address, corresponding to multiple alternative routes.After all
matches are found, the best match must be selected.
-
Routing Table, ContinuedIf only one row matches, it will be
selected as the best row match.Destination IP address =
192.168.6.7RowDestinationNetwork orSubnetMask
(/Prefix)Metric(Cost)Next-HopRouterInterface3192.168.0.0255.255.0.0
(/16)12G2
-
Routing Table, ContinuedThe default row always matchesMask
0.0.0.0 applied to anything results in 0.0.0.0This always matches
the Network/Subnet value 0.0.0.0The router specified for this row
(H) is the default router
RowDestinationNetwork orSubnetMask
(/Prefix)Metric(Cost)Next-HopRouterInterface130.0.0.00.0.0.0
(/0)5H3
-
Routing Table, ContinuedIf there are multiple matches, the row
with the longest length of match is selectedThis is Row 7 for
128.171.17.56 (24 bit match)Row 1s length of match is only 16
bitsLonger matches often are routes to a particular subnet within a
network
-
Routing Table, ContinuedIf there are multiple rows with the same
lengths of match, the metric column compares alternative routes.If
the metric is cost, the smallest metric wins (20)If the metric is
speed, the largest metric wins (34)
RowDestinationNetwork orSubnetMask
(/Prefix)Metric(Cost)Next-HopRouterInterface5172.29.8.0255.255.255.0
(/24)34F18172.29.8.0255.255.255.0 (/24)20H3
-
The SituationThe router first evaluated the IP destination
address of the arriving packet against all rows and noted the
matching rows.The router then selected the best-match row.Now, the
router examines the interface and next-hop router fields in the
best-match row to determine what to do with the packet.
-
Interface and Next-Hop
RouterRouterForwardingPacketPossibleNext-HopRouterPossibleNext-HopRouterPossibleDestinationHostPacket
to Router Bon Interface 5Router ARouter BRouter CIP Subnet
onInterface (Port 5)Packet must be sent toa particular host
orrouter on the subnetout a particularinterface (port).
-
Routing Table, ContinuedThe Interface specifies the out port on
the router.A subnet is attached to this interface.Next Hop Router
(NHR) column specifies a specific NHR on that subnet.For Row 5,
send packet to NHR F on the subnet out Interface
1.RowDestinationNetwork orSubnetMask
(/Prefix)Metric(Cost)Next-HopRouterInterface5172.29.8.0255.255.255.0
(/24)34F1
-
Routing Table, ContinuedIf Next-Hop Router Field says Local,
Then the destination host in on the subnet attached to the
interface (1).Instead of sending the packet to a next-hop router on
the subnet, the router will send the packet to its destination
address.
RowDestinationNetwork orSubnetMask
(/Prefix)Metric(Cost)Next-HopRouterInterface2172.30.33.0255.255.255.0
(/24)0Local1
-
Routing RecapThe router looks at the destination IP address in
the packet.First, the router finds all matching rows.Second,
selects the best matching row.Third, sends packet back out the rows
specified interface, to the rows specified next-hop router.Begins
to process the next packet.
-
References:
Napier, A., Judd, P., Rivers, O., and Adams, A.,
(2003)E-Business TechnologiesThomson Course TechnologiesISBN:
0-619-06319-xPanko, R (2005)Business Data Networks and
Communications, 5th edition, Prentice HallISBN:
0-13-127315-9SchneiderE-Business, Eighth EditionISBN-13:
978-0-324-78807-5Hogan, F., (2005)Internet Presentation
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