ITEC 275 Computer Networks

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ITEC 275 Computer Networks Switching, Routing,
and WANs

• Week 11
• Robert DAndrea
• Winter 2018

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Agenda

• Learning Activities
• TDM and FDM differences
• Industry Tests
• Build and Test a Prototype
• Write and Implement a Test Plan
• Tools for Testing a Network Design
• Multicasting
• QoS
• Queuing and Traffic Shaping

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ATM Video

• Frame Relay, ATM, and MPLS videos
• https//www.youtube.com/watch?vSz1PThotOUQ

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TDM and FDM

• TDM (Time Division Multiplexing) and FDM
  (Frequency Division Multiplexing) are two methods
  of multiplexing multiple signals into a single
  carrier. Multiplexing is the process of combining
  multiple signals into one, in such a manner that
  each individual signal can be retrieved at the
  destination. Since multiple signals are occupying
  the channel, they need to share the resource in
  some manner.

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TDM and FDM

• The primary difference between FDM and TDM is
  how they divide the channels. FDM divides the
  channel into two or more frequency ranges that do
  not overlap. TDM divides and allocates certain
  time periods to each channel in an alternating
  manner. Because of this fact, we can say that
  TDM, each signal uses all of the bandwidth some
  of the time, while for FDM, each signal uses a
  small portion of the bandwidth all of the time.

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TDM and FDM

• 1. FDM divides the channel into multiple, but
  smaller frequency ranges to accommodate more
  users, while TDM divides a channel by allocating
  a time period for each channel.
• 2. TDM provides much better flexibility compared
  to FDM.
• 3. FDM proves much better latency compared to
  TDM.
• 4. TDM and FDM can be used in tandem.

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FDM

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TDM and FDM

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Reasons for Network Testing

• Verify that the design meets key business and
  technical goals
• Validate LAN and WAN technology and device
  selections
• Verify that a service provider provides the
  agreed-up service
• Identify bottlenecks or connectivity problems
• Determine optimization techniques that will be
  necessary

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Reasons for Network Testing

• Proving that your network design is better than a
  competing design
• Passing an acceptance test that gives you
  approval to go forward with the network
  implementation
• Reassure mangers and co-workers that your design
  is effective
• Identifying any risks that might impede
  implementation and planning for contingencies
• Determine how much additional testing might be
  required. Will the new system be deployed as a
  pilot and undergo additional testing before being
  implemented

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Testing Your Network Design

• Use industry testing services
• Build and test a prototype system
• Use third-party and Cisco tools

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Respected Independent Test Labs

• Network Testing Labs' experts write hardware and
  software product reviews, state-of-the-art
  analyses, feature articles, in-depth technology
  workshops, cover stories, buyers guides and
  in-depth technology outlooks. Experts have spoken
  on a number of topics at Comdex, Interop, PC Expo
  and other venues. In addition, they've created
  industry standard network benchmark software,
  database benchmark software and network
  diagnostic utilities.

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Respected Independent Test Labs

• The Interoperability Lab at the University of New
  Hampshire (IOL)
• ICSA Labs
• Miercom Labs
• AppLabs
• The Tolly Group
• Penetration Testing test your network and
  applications before the bad guys do.

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Simple verses Complex Network Designs

• Simple network designs can rely on test results
  from vendors, independent labs, or trade journals
  to prove to your customer that your design will
  perform as intended.
• Complex network designs require more
  considerations.
• Testing should be implemented in-house
• Testing will require more than component testing.
  There will be a need for unit, integration, and
  system testing.

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Scope of a Prototype System

• Normally, it is impractical to implement a
  full-scale network system.
• A prototype should verify important capabilities
  and functions that might not perform adequately.
• Risky functions include complex, intricate
  functions and functions that were influenced by
  the need to make tradeoffs with other network
  components.

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Live Production Network

• Perform initial testing during off-hours to
  minimize issues with user community, performance,
  and existing traffic flow.
• Perform final testing during normal hours and
  benchmark the performance.
• Perform final testing at various times to
  exercise the network during typical loads and
  benchmark the performance.

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Test Plan

• Implement a Test Plan?
• A test plan is primarily comprised of test cases
  and test items. Think of a test case as a
  scenario or a finite state in which your network
  might find itself. 
• In each test case, you'll have a list of test
  items or functions or features that you want to
  evaluate. Each test item should include not just
  an action, but the success criteria, and if you
  want to get more sophisticated, the testing too
  must be more critical. For example, you might
  want to make sure a business-critical application
  still work after a network change. So you'd
  arrange to have the application owners create a
  transaction or operate the application. 

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Components of a Test Plan

• Test objectives and acceptance criteria
• The types of tests that will be run
• Network equipment and other resources required
• Testing scripts
• The timeline and milestones for the testing a
  project

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Components of a Test Plan

• Test objectives and acceptance criteria
• Objectives and acceptance should be based on a
  customers business and technical goals
• Acceptance of test results are acceptable by both
  the customer and the tester.
• Measure response time
• Measure applications throughput
• Measure the amount of time it takes to hear a
  dial tone using Voice over IP
• Establish a baseline measurement of CRC errors

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Test Objectives and Acceptance Criteria for a
Test Plan

• Specific and concrete
• Based on business and technical goals
• Clear criteria for declaring that a test passed
  or failed
• Avoid biases and preconceived notions about
  outcomes
• If appropriate, reference an established baseline

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Test Plan Considerations and Implementation

• Network Connectivity Section
• Is Layer 2 set up appropriately? (VLANs on the
  right trunks, PVCs, etc.)
• Do your router tables have the proper routes?
  (Check the next hops and ages, too.)
• Can you ping everywhere in the network?
  (Performance Are the times acceptable?)
• Do trace routes show paths you would expect?
• If you load balance across the core of your
  network, verify each link is being used.
• Is DHCP handing out addresses?
• DNS resolving names properly?
• Does your remote access still work?

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Test Plan Considerations

• Application Connectivity Section
• Does VOIP work? Is it showing up in the right
  queues?
• Are your firewalls and proxies blocking and
  allowing traffic appropriately?
• Can you browse the Web?
• Are your network management and logging systems
  working?
• Do your business applications work? (And do
  transactions complete in an acceptable time?)
• Are backup jobs still working?

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Achieve Success with a New Network Design

• Your chances of success are much greater if you
  perform several simple tests along the way,
  rather than waiting until you think you're done
  and discovering that something doesn't work.
  Performing simple incremental tests along the way
  will help testers and customers maintain a sense
  of truthfulness and confidence about in the
  system being tested.

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Types of Tests

• Application response-time tests with terminal
• Throughput tests (I/O)
• Availability tests (failure test)
• Regression tests (does the network perform
  similarly after changes were implemented)

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Types of Tests

• What are the benefits of Protocol Testing?
• To understand the behavior of a protocol, it must
  be tested to observe the protocols functionality
• Verify every phase of testing life cycle for
• Functionality testing
• Interoperability testing (IOT) is the process of
  testing to determine the interoperability of a
  software product
• Performance
• Obtain tools to generate and test the protocol
  messages

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Types of Tests

• Why is Protocol Testing necessary?
• Different vendor products need to communicate
  with each other.
• If any product is using this standards in their
  devices they are interoperable with other vendor
  devices as both must meet compliance to Standards
  of IETF/RFC to study the network through their
  packet data.
• Protocol testing ensures proper functionality of
  various elements of a message. It also ensures
  whether it was designed as per specification.

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Resources Needed for Testing

• A Test Plan should include a network topology
  drawing for tester to be able to reference.
• A list of switches, routers, bridges, firewalls,
  servers, telephone equipment, and wireless
  access points.
• A list of documented version numbers for
  hardware and software.
• Scheduled time in a lab either at your site or
  the customers site
• Power, air conditioning, rack space, and other
  physical resources
• Help from co-workers or customer staff
• Help from users to test applications
• Network addresses and names

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Resources Needed for Testing

• How it is carried out?
• Objective To test the protocol
• i.e. to check every node with their packet data.
• Tools Protocol Analyzer or WireShark and
  simulator.

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Example Test Script
Server 1
Workstations
Firewall
Network A
Network B
Protocol Analyzer
Protocol Analyzer
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Example Test Script (continued)

• Based on the previous slide
• Test objective.
• Assess the firewalls capability to block
  Application ABC traffic, during both light and
  moderately heavy load conditions.
• Acceptance criterion.
• The firewall should block the TCP SYN request
  from every workstation on Network A that
  attempts to set up an Application ABC session
  with Server 1 on Network B. The firewall should
  send each workstation a TCP RST (reset) packet.

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Example Test Script (continued)

1. Start capturing network traffic on the protocol
   analyzer on Network A.
2. Start capturing network traffic on the protocol
   analyzer on Network B.
3. Run Application ABC on a workstation located on
   Network A and access Server 1 on Network B.
4. Stop capturing network traffic on the protocol
   analyzers.

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Example Test Script (continued)

• 5. Display data on Network As protocol analyzer
  and verify that the analyzer captured a TCP SYN
  packet from the workstation. Verify that the
  network layer destination address is Server 1 on
  Network B, and the destination port is port 1234
  (the port number for Application ABC). Verify
  that the firewall responded to the workstation
  with a TCP RST packet.

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Example Test Script (continued)

1. Display data on Network Bs protocol analyzer and
   verify that the analyzer did not capture any
   Application-ABC traffic from the workstation.
2. Log the results of the test in the project log
   file.
3. Save the protocol-analyzer trace files to the
   project trace-file directory.
4. Gradually increase the workload on the firewall,
   by increasing the number of workstations on
   Network A one at a time, until 50 workstations
   are running Application ABC and attempting to
   reach Server 1. Repeat steps 1 through 8 after
   each workstation is added to the test.

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Example Test Script (continued)

• Host A sends a TCP SYNchronize packet to Host B
• Host B receives A's SYN
• Host B sends a SYNchronize-ACKnowledgement
• Host A receives B's SYN-ACK
• Host A sends ACKnowledge
• Host B receives ACK.
• TCP socket connection is ESTABLISHED.
  

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Tools for Testing a Network Design

• Network-management and monitoring tools. These
  monitoring tools are used to alert network
  management to problems and report significant
  network problems.
• Traffic generation tools
• Modeling and simulation tools
• QoS and service-level management tools
• Protocol analyzer

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Tools for Testing a Network Design

• The following list of products are probably more
  related to network monitoring than network
  design, but don't forget that two important steps
  in the top-down network design methodology are
  characterizing the existing network and testing
  the new network.
• Big Brother Professional Edition
• Ixia IxN2X Multiservice Test Solution
• LANSurveyor
• Multi Router Traffic Grapher
• Nagios
• NetIQ

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Tools for Testing a Network Design

• Online Erlang Traffic Calculators
• OPNET
• Orion NetFlow Traffic Analyzer (NTA)
• NetMRI
• Tivoli
• Visio Enterprise Network Tools
• WANDL's Network-Planning and Analysis Tools
• WhatsUp Gold

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Protocol Analyzer Tool

• A protocol analyzer is used to analyze traffic
  behavior, errors, utilization, efficiency, and
  rates of broadcast and multicast packets.
• A protocol analyzer can be a computer
  program (WireShark) or a piece of computer
  hardware that can intercept and log traffic
  passing over a digital network or part of a
  network. As data streams flow across the network,
  the sniffer captures each packet and, if needed,
  decodes the packet's raw data, showing the values
  of various fields in the packet, and analyzes its
  content according to the appropriate RFC or other
  specifications.

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Simulation Tool

• A simulation tool enables you to develop a model
  of a network, estimate the performance of the
  network and compare alternatives for implementing
  the network.
• iTrinegy Network Emulator (INE) products enable
  you to realistically recreate a wide variety of
  network conditions like latency, jitter, packet
  loss/error/reordering and bandwidth restrictions
  so that you can simulate environments such as
  Wide Area Networks (WANs), Wireless LANs, GPRS,
  3G, IP over Radio/Radio over IP(RoIP), Satellite
  or MPLS networks.

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Command Tools

• Test Tools
• Command Format
• ipconfig
• ping ltIP addressgt ping
• ping ltDNS namegt ping yahoo.com
• tracert ltDNS namegt tracert yahoo.com
• nslookup ltDNS namegt nslookup yahoo.com
• netstat netstat -a

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Reasons to Optimize

• Meet key business and technical goals
• Use bandwidth efficiently
• Control delay and jitter
• Reduce serialization delay
• Support preferential service for essential
  applications
• Meet Quality of Service (QoS) requirements (IP
  Multicast)

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IP Multicast
Server
Server
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IP Multicast

• Router/MCS
• The Miscellaneous Control Subsystem (MCS) works
  with its companion Routing Engine provides
  control and monitoring functions for router
  components. It also generates a clock signal for
  the SONET/SDH interfaces on the router.

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IP Multicast

• Applications
• Applications that take advantage of multicast
  include video conferencing, corporate
  communications, distance learning, and
  distribution of software, stock quotes, and news.

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IP Multicast Helps Optimize Bandwidth Usage

• With IP multicast, you can send a high-volume
  multimedia stream just once instead of once for
  each user
• Requires support for
• Multicast addressing
• Multicast registration (IGMP)
• Multicast routing protocols

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IP Multicast Addresses

• IPv4 Multicast Addresses
• 224.0.0.0 to 239.255.255.255
• IPv6 Multicast Addresses
• FF020000001 All Nodes Address
• FF020000002 All Routers Address

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IP Multicast Helps Optimize Bandwidth Usage

• To map an IP multicast address to a MAC-layer
  multicast address, the low order 23 bits of the
  IP multicast address are mapped directly to the
  low order 23 bits in the MAC-layer multicast
  address. Because the first 4 bits of an IP
  multicast address are fixed according to the
  class D convention, there are 5 bits in the IP
  multicast address that do not map to the
  MAC-layer multicast address. 

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IP Multicast Addressing

• Uses Class D multicast destination address
• 224.0.0.0 to 239.255.255.255
• Converted to a MAC-layer multicast destination
  address
• The low-order 23 bits of the Class D address
  become the low-order 23 bits of the MAC-layer
  address
• The top 9 bits of the Class D address are not
  used
• The top 25 bits of the MAC-layer address are
  0x01005E followed by a binary 0

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Internet Group Management Protocol (IGMP)

• Allows a host to join a multicast group
• Host transmits a membership-report message to
  inform routers on the segment that traffic for a
  group should be multicast to the hosts segment
• IGMPv2 has support for a router more quickly
  learning that the last host on a segment has left
  a group

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Multicast Routing Protocols

• Becoming obsolete
• Multicast OSPF (MOSPF)
• Distance Vector Multicast Routing Protocol
  (DVMRP)
• Still used
• Protocol Independent Multicast (PIM)
• Dense-Mode PIM
• Sparse-Mode PIM

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Multicast Routing Protocols
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Multicast Routing Protocols

• What is PIM?
• Protocol-Independent Multicast (PIM) is a family
  of multicast routing protocol for Internet
  Protocol (IP) networks that provide one-to-many
  and many-to-many distribution of data over a LAN,
  WAN
• or the Internet. It is termed protocol -
  independent because PIM does not include its
  own topology discovery mechanism, but instead
  uses routing information supplied by
  other routing protocols.

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PIM (Protocol Independent Multicast)

• What is PIM Dense Mode?
• Dense mode is used when there are many members
  (employees listen to a company president).
• Dense PIM does not require the computation of
  routing tables.

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PIM (Protocol Independent Multicast)

• What is PIM Dense Mode?
• Dense mode PIM is the older and simpler PIM
  mode. It works well in small networks where there
  are a large number of listeners, but is
  inefficient in larger network.

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PIM Dense Mode
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PIM (Protocol Independent Multicast)

• What is PIM Sparse Mode?
• Sparse mode utilizes a rendezvous point (RP). A
  rendezvous point provides a registration service
  for a multicast group.
• Sparse mode PIM relies on IGMP which let a host
  join a group by sending a membership-report
  message, and detach from a group by sending a
  leave message.

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PIM (Protocol Independent Multicast)

• What is PIM Sparse Mode?
• PIM Sparse Mode (PIM-SM) explicitly builds
  unidirectional shared trees rooted at
  a rendezvous point (RP) per group, and optionally
  creates shortest-path trees per source. PIM-SM
  generally scales fairly well for wide-area usage.

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Serialization

• What is serialization?
• Serialization is the process of translating data
  structures or object state into a format that can
  be stored (for example, in a file or
  memory buffer, or transmitted across
  a network connection link) and reconstructed
  later in the same or another computer
  environment. When the resulting series of bits is
  reread according to the serialization format, it
  can be used to create a semantically identical
  clone of the original object.

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Serialization Delay

• What is serialization delay? Serialization
  delay is the time it takes for a unit of data,
  such as a packet, to be serialized for
  transmission on a narrow channel such as a cable.
  Serialization delay is dependent on size, which
  means that longer packets experience longer
  delays over a given network path. Serialization
  delay is also dependent on channel capacity
  ("bandwidth"), which means that for equal-size
  packets, the faster the link, the lower the
  serialization delay.

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Reducing Serialization Delay

• Link-layer fragmentation and interleaving
• Breaks up and reassembles frames
• Multilink PPP
• Frame Relay FRF.12
• Compressed Real Time Protocol
• RTP is used for voice and video
• Compressed RTP compresses the RTP, UDP, and IP
  header from 40 bytes to 2 to 4 bytes

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Reducing Serialization Delay
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A Few Technologies for Meeting QoS Requirements

• IETF controlled load service
• IETF guaranteed service
• IP precedence
• IP differentiated services

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IP Type of Service Field

• The type of service field in the IP header is
  divided into two subfields
• The 3-bit precedence subfield supports eight
  levels of priority
• The 4-bit type of service subfield supports four
  types of service
• Although IP precedence is still used, the type of
  service subfield was hardly ever used

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IP Type of Service Field
Type of Service Subfield
Bit
0
3
4
5
6
7
D Delay T Throughput R Reliability C Cost
Precedence
D
T
R
C
0
0
8
15
24
31
Version
Header Length
Type of Service
Total Length
Bit
Identification
Flags
Fragment Offset
Time to Live
Protocol
Header Checksum
Source IP Address
Destination IP Address
Options
Padding
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IP Differentiated Services (DS) Field

• RFC 2474 redefines the type of service field as
  the Differentiated Services (DS) field
• Bits 0 through 5 are the Differentiated Services
  Codepoint (DSCP) subfield
• Has essentially the same goal as the precedence
  subfield
• Influences queuing and packet dropping decisions
  for IP packets at a router output interface
• Bits 6 and 7 are the Explicit Congestion
  Notification (ECN) subfield

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IP Differentiated Services (DS) Field
0
6
Differentiated Services Codepoint
Explicit Congestion Notification
0
8
15
24
31
Header Length
Version
Differentiated Services
Total Length
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Resource Reservation Protocol (RSVP)

• RSVP complements the IP type-of-service,
  precedence, DSCP, and traffic-class capabilities
  inherent in an IP header.
• RSVP supports mechanisms for hosts to specify QoS
  requirements for individual traffic flow.
• RSVP can be deployed on LANs and enterprise WANs
  to support multimedia applications or other types
  of applications with strict QoS requirements.

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Resource Reservation Protocol (RSVP)

• IP header type-of-service capabilities and RSVP
  are examples of QoS signaling protocols.

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Classifying LAN Traffic

• IEEE 802.1p
• Classifies traffic at the data-link layer
• Supports eight classes of service
• A switch can have a separate queue for each class
  and service the highest-priority queues first

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Cisco Switching Techniques

• Process switching is the slowest switching method
• Fast switching allows highest throughput by
  switching a packet using an entry in the
  fast-cache that was created when a previous
  packet to the same destination was processed.
• NetFlow switching is optimized for environments
  where services must be applied to packets to
  implement security, QoS features, and traffic
  accounting. Example Internet and enterprise
  network environment boundary.

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Cisco Switching Techniques

• Cisco Express Forwarding (CEF) is a technique for
  switching packets quickly across large backbone
  networks and the Internet.
• CEF depended on a forwarding information base
  (FIB), rather than caching techniques.
• FIB allows CEF to use less CPU resources compared
  to other Layer 3 switching methods. FIB contains
  forwarding information for all routes in the
  routing tables.

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Cisco Switching Techniques

• Why did CEF evolve?
• With the introduction of web-based applications
  and other interactive applications that are
  characterized by sessions of short duration to
  multiple addresses.
• It became very apparent that the cache-based
  system could not deliver the needed performance
  for these applications.

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Cisco Queuing Services

• First in, first out (FIFO) queuing store
  packets when the network is congested and forward
  the packets in the order they arrived in when
  there is no congestion. Disadvantage No packet
  priority scheme.
• Priority queuing ensures that important traffic
  is processed first. Priority is based on the type
  of protocol, incoming interface, packet size, and
  source or destination address. The priorities are
  high, medium, normal, and low.

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Cisco Queuing Services

• Custom queuing is designed to allow the network
  to be shared among applications with different
  minimum bandwidth or latency requirements. Custom
  queuing provides different amounts of queue space
  to different protocols and handles the queues in
  round-robin manner. A particular protocol can be
  prioritized by assigning it more queue space.
• Custom queuing can be used to guarantee
  bandwidth at a potential congestion point.

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Cisco Queuing Services

• Custom queuing helps ensure that each traffic
  type receives a fixed portion of available
  bandwidth and that when the link is under stress,
  no application receives more than a predetermined
  proportion of capacity.
• Weighted fair queuing (WFQ) operates from
  algorithms designed to reduce delay variability
  and provide predictable throughput and response
  time for traffic flows. Applications with small
  payloads are not starved of bandwidth by
  applications that send large packets.

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Cisco Queuing Services

• Class-based Weighted Fair Queuing (CBWFQ)
  combines the best scenarios of priority, custom,
  and weight-fair queuing.
• Class-based WFQ allows you to define traffic
  classes based on matching criteria such as
  protocol, access control lists, and input
  interfaces.
• Low latency queuing (LLQ) combines priority
  queuing with CBWFQ. LLQ brings strict priority
  queuing to CBWFQ. Strict priority queuing allows
  delay-sensitive data such as voice to be sent
  before packets in other queues are sent.

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Priority Queuing
START
NO
Packet in high queue?
NO
Packet in medium queue?
YES
NO
Packet in normal queue?
YES
NO
Packet in low queue?
YES
YES
Continue
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Custom Queuing
START (with Queue 1)
NO
YES
Reached transmission window size?
NO
YES
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Low-Latency Queuing

• One queue always gets the green light
• Use this for voice
• Combine this with class-based weighted fair
  queuing
• Define traffic classes based on protocols, access
  control lists, and input interfaces
• Assign characteristics to classes such as
  bandwidth required and the maximum number of
  packets that can be queued for the class

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Random Early Detection (RED)

• Congestion avoidance rather than congestion
  management
• Monitors traffic loads and randomly discards
  packets if congestion increases
• Source nodes detect dropped packets and slow down
• Works best with TCP
• Weighted Random Early Detection
• Ciscos implementation uses IP precedence or the
  DS field instead of just randomly dropping packets

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Traffic Shaping

• Manage and control network traffic to avoid
  bottlenecks
• Avoid overwhelming a downstream router or link
• Reduce outbound traffic for a flow to a
  configured bit rate
• Queue bursts of traffic for that flow
• In summary, traffic shaping is the manipulation
  and prioritization of network traffic to reduce
  the impact of heavy users or machines from
  effecting other users.

84
Committed Access Rate (CAR)

• Cisco feature for classifying and policing
  traffic on an incoming interface
• Supports policies regarding how traffic that
  exceeds a certain bandwidth allocation should be
  handled
• Can drop a packet or change the IP precedence or
  DSCP bits

85
Security Penetration

• A penetration test is a proactive and authorized
  attempt to evaluate the security of an IT
  infrastructure by safely attempting to exploit
  system vulnerabilities, including OS, service and
  application flaws, improper configurations, and
  even risky end-user behavior. Such assessments
  are also useful in validating the efficacy of
  defensive mechanisms, as well as end-users
  adherence to security policies.

86
Security Penetration

• Penetration tests are typically performed using
  manual or automated technologies to
  systematically compromise servers, endpoints, web
  applications, wireless networks, network devices,
  mobile devices and other potential points of
  exposure. Once vulnerabilities have been
  successfully exploited on a particular system,
  testers may attempt to use the compromised system
  to launch subsequent exploits at other internal
  resources, specifically by trying to
  incrementally achieve higher levels of security
  clearance and deeper access to electronic assets
  and information via privilege escalation.

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Summary

• An untested network design probably wont work.
• Its often not practical to test the entire
  design.
• However, by using industry testing services and
  tools, as well as your own testing scripts, you
  can (and should) test the complex, risky, and key
  components of a network design.

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Summary

• Optimization provides the high bandwidth, low
  delay, and controlled jitter required by many
  critical business applications
• To minimize bandwidth utilization by multimedia
  applications, use IP multicast
• To reduce serialization delay, use link
  fragmentation and compressed RTP
• To support QoS and optimize performance, use IP
  precedence, DSCP, 802.1p. advanced switching and
  queuing methods, RED, CAR, etc.

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This Weeks Outcomes

• Industry Tests
• Build and Test a Prototype
• Write and Implement a Test Plan
• Tools for Testing a Network Design
• Multicasting
• QoS
• Queuing and Traffic Shaping

90
Q A

• Questions, comments, concerns?