Home > Articles > Cisco Network Technology > General Networking > Campus Distribution (Cisco Catalyst 4500) QoS Design

Campus Distribution (Cisco Catalyst 4500) QoS Design

  • Sample Chapter is provided courtesy of Cisco Press.
  • Date: Jan 22, 2014.

Chapter Description

This chapter discusses the best-practice QoS design recommendations for the Cisco Catalyst 4500 (Supervisor 6-E/7-E) series switch in the role of a campus distribution layer switch.

Queuing Models

Ingress queuing is not supported on the Catalyst 4500; only egress queuing is supported.

The Catalyst 4500 supports a strict-priority hardware queue with (up to) seven additional nonpriority hardware queues. In addition, the Catalyst 4500 supports DSCP-to-queue mapping.

At the time of this writing, DSCP-based weighted random early detection (WRED) is not supported on the Catalyst 4500 platform. However, the Catalyst 4500 family uses a platform-specific congestion avoidance algorithm to provide active queue management (AQM), namely Dynamic Buffer Limiting (DBL). DBL tracks the queue length for each traffic flow in the switch. When the queue length of a flow exceeds its limit, DBL drop packets or sets the Explicit Congestion Notification (ECN) bits in the packet headers. The DBL algorithm can identify belligerent flows (that is, unchecked/nonadaptive/inelastic flows) and drop these more aggressively. Belligerent flows can use excessive bandwidth and switch buffers, resulting in poor application performance for well-behaved flows. Therefore, DBL can induce not only random “probabilistic drops” (in a manner similar to WRED), but also “belligerent flow drops,” both of which are counted and displayed via the show policy-map interface command output on classes where DBL has been enabled (as demonstrated later in Example 15-4).

Therefore, the egress queuing model for the Catalyst 4500 platform can be expressed as 1P7Q1T+DBL.

The Catalyst 4500 can be configured to support 4-class, 8-class, or 12-class queuing models, as discussed in the following sections.

Four-Class Egress Queuing Model

In the four-class model (illustrated in Figures 11-3 and 11-4 in Chapter 11, “QoS Design Principles and Strategies”), the application class to queue mappings are as follows:

  • Real-time traffic (marked EF) is assigned to the priority queue (which may be optionally policed to 30 percent bandwidth).
  • Control traffic (marked CS3) is assigned to a dedicated nonpriority queue with a 10 percent bandwidth allocation.
  • Transactional data (marked AF2) is assigned to another dedicated nonpriority queue with a 35 percent bandwidth allocation with DBL enabled.
  • Best-effort traffic (marked DF) is assigned to a default queue with 25 percent bandwidth allocation with DBL enabled.

Figure 15-3 illustrates the resulting four-class (1P3Q1T+DBL) egress queuing model for the Catalyst 4500.

Figure 15-3

Figure 15-3 Catalyst 4500 Four-Class Egress Queuing Model

Example 15-1 shows the corresponding configuration for four-class (1P3Q1T+DBL) egress queuing on the Catalyst 4500.

Example 15-1 Four-Class (1P3Q1T+DBL) Egress Queuing Configuration Example on a Catalyst 4500

 ! This section configures the class maps for the egress queuing policy
C4500(config)# class-map match-all PRIORITY-QUEUE
C4500(config-cmap)# match dscp ef
 ! VoIP (EF) is mapped to the PQ
C4500(config)# class-map match-all CONTROL-QUEUE
C4500(config-cmap)# match dscp cs3
 ! Signaling (CS3) is mapped to a dedicated queue
C4500(config)# class-map match-all TRANSACTIONAL-DATA-QUEUE
C4500(config-cmap)# match dscp af21 af22 af23
 ! Transactional Data (AF2) is mapped to a dedicated queue


 ! This section configures the four-class egress queuing policy map
C4500(config)# policy-map 1P3Q1T
C4500(config-pmap-c)# class PRIORITY-QUEUE
C4500(config-pmap-c)#  priority
 ! Enables the priority queue
C4500(config-pmap-c)# class CONTROL-QUEUE
C4500(config-pmap-c)#  bandwidth remaining percent 10
 ! Defines the control queue with 10% BW remaining
C4500(config-pmap-c)# class TRANSACTIONAL-DATA-QUEUE
C4500(config-pmap-c)#  bandwidth remaining percent 35
C4500(config-pmap-c)#  dbl
 ! Defines a transactional data queue with 35% BW remaining + DBL
C4500(config-pmap-c)# class class-default
C4500(config-pmap-c)#  bandwidth remaining percent 25
C4500(config-pmap-c)#  dbl
 ! Provisions the default/Best Effort queue with 25% BW remaining + DBL


 ! This section attaches the egress queuing policy to the interface(s)
C4500(config)# interface range TenGigabitEthernet 1/1-2
C4500(config-if-range)# service-policy output 1P3Q1T

You can verify the configuration in Example 15-1 with the following commands:

  • show class-map
  • show policy-map
  • show policy-map interface

Eight-Class Egress Queuing Model

In the eight-class model (illustrated in Figures 11-5 and 11-6), the application class to queue mappings are as follows:

  • Real-time traffic (marked EF) is assigned to the priority queue (which may be optionally policed to 10 percent bandwidth).
  • Interactive video (marked AF4) is assigned to a dedicated nonpriority queue with a 23 percent bandwidth allocation with DBL enabled.
  • Streaming video (marked AF3) is assigned to a dedicated nonpriority queue with a 10 percent bandwidth allocation with DBL enabled.
  • Network control traffic (marked CS6) is assigned to a dedicated nonpriority queue with a 5 percent bandwidth allocation.
  • Signaling traffic (marked CS3) is assigned to a dedicated nonpriority queue with a 2 percent bandwidth allocation.
  • Transactional data (marked AF2) is assigned to dedicated nonpriority queue with a 24 percent bandwidth allocation with DBL enabled.
  • Scavenger traffic (marked CS1) is constrained within a dedicated nonpriority queue with a 1 percent bandwidth allocation.
  • Best-effort traffic (marked DF) is assigned to a default queue with 25 percent bandwidth allocation with DBL enabled.

Figure 15-4 illustrates the resulting eight-class (1P7Q1T+DBL) egress queuing model for the Catalyst 4500.

Figure 15-4

Figure 15-4 Catalyst 4500 Eight-Class (1P7Q1T+DBL) Egress Queuing Model

Example 15-2 shows the corresponding configuration for eight-class (1P7Q1T+DBL) egress queuing on the Catalyst 4500.

Example 15-2 Eight-Class (1P7Q1T+DBL) Egress Queuing Configuration Example on a Catalyst 4500

 ! This section configures the class maps for the egress queuing policy
C4500(config)# class-map match-all PRIORITY-QUEUE
C4500(config-cmap)# match dscp ef
 ! VoIP (EF) is mapped to the PQ
C4500(config)# class-map match-all INTERACTIVE-VIDEO-QUEUE
C4500(config-cmap)# match dscp af41 af42 af43
 ! Interactive-Video (AF4) is assigned a dedicated queue
C4500(config)# class-map match-all STREAMING-VIDEO-QUEUE
C4500(config-cmap)# match dscp af31 af32 af33
 ! Streaming-Video (AF3) is assigned a dedicated queue
C4500(config)# class-map match-all CONTROL-QUEUE
C4500(config-cmap)# match dscp cs6
 ! Network Control (CS6) is mapped to a dedicated queue
C4500(config)# class-map match-all SIGNALING-QUEUE
C4500(config-cmap)# match dscp cs3
 ! Signaling (CS3) is mapped to a dedicated queue
C4500(config)# class-map match-all TRANSACTIONAL-DATA-QUEUE
C4500(config-cmap)# match dscp af21 af22 af23
 ! Transactional Data (AF2) is assigned a dedicated queue
C4500(config)# class-map match-all SCAVENGER-QUEUE
C4500(config-cmap)# match dscp cs1
 ! Scavenger (CS1) is assigned a dedicated queue

 ! This section configures the 1P7Q1T+DBL egress queuing policy map
C4500(config)# policy-map 1P7Q1T
C4500(config-pmap-c)# class PRIORITY-QUEUE
C4500(config-pmap-c)#  priority
 ! Defines a priority queue
C4500(config-pmap-c)# class INTERACTIVE-VIDEO-QUEUE
C4500(config-pmap-c)#  bandwidth remaining percent 23
C4500(config-pmap-c)#  dbl
 ! Defines a interactive-video queue with 23% BW remaining + DBL
C4500(config-pmap-c)# class STREAMING-VIDEO-QUEUE
C4500(config-pmap-c)# bandwidth remaining percent 10
C4500(config-pmap-c)#  dbl
 ! Defines a streaming-video queue with 10% BW remaining + DBL
C4500(config-pmap-c)# class CONTROL-QUEUE
C4500(config-pmap-c)#  bandwidth remaining percent 5
 ! Defines a control/management queue with 5% BW remaining
C4500(config-pmap-c)# class SIGNALING-QUEUE
C4500(config-pmap-c)#  bandwidth remaining percent 2
 ! Defines a signaling queue with 2% BW remaining
C4500(config-pmap-c)# class TRANSACTIONAL-DATA-QUEUE
C4500(config-pmap-c)#  bandwidth remaining percent 24
C4500(config-pmap-c)#  dbl
 ! Defines a transactional data queue with 24% BW remaining + DBL
C4500(config-pmap-c)# class SCAVENGER-QUEUE
C4500(config-pmap-c)#  bandwidth remaining percent 1
 ! Defines a (minimal) scavenger queue with 1% BW remaining/limit
C4500(config-pmap-c)# class class-default
C4500(config-pmap-c)#  bandwidth remaining percent 25
C4500(config-pmap-c)#  dbl
 ! Provisions the default/Best Effort queue with 25% BW remaining + DBL


 ! This section attaches the egress queuing policy to the interface(s)
C4500(config)# interface range TenGigabitEthernet 1/1-2
C4500(config-if-range)# service-policy output 1P7Q1T

You can verify the configuration in Example 15-2 with the following commands:

  • show class-map
  • show policy-map
  • show policy-map interface

Twelve-Class Egress Queuing Model

In the 12-class model (illustrated in Figures 11-7 and 11-8), the application class to queue mappings are as follows:

  • Voice (marked EF), broadcast video (marked CS5), and real-time interactive traffic (marked CS4) is all assigned to the priority queue (which may be optionally policed to 30 percent bandwidth).
  • Multimedia-conferencing traffic (marked AF4) is assigned to a dedicated nonpriority queue with a 10 percent bandwidth allocation with DBL enabled.
  • Multimedia-streaming traffic (marked AF3) is assigned to a dedicated nonpriority queue with a 10 percent bandwidth allocation with DBL enabled.
  • Network control traffic (marked CS6), signaling traffic (marked CS3) and network management traffic (marked CS2) is all assigned to a dedicated nonpriority queue with a 10 percent bandwidth allocation; optionally, CS7 traffic may also be mapped to this queue.
  • Transactional data traffic (marked AF2) is assigned to dedicated nonpriority queue with a 10 percent bandwidth allocation with DBL enabled.
  • Bulk data traffic (marked AF1) is assigned to a dedicated nonpriority queue with 4 percent bandwidth allocation with DBL enabled.
  • Scavenger traffic (marked CS1) is constrained within a dedicated nonpriority queue with a 1 percent bandwidth allocation.
  • Best-effort traffic (marked DF) is assigned to a default queue with 25 percent bandwidth allocation with DBL enabled.

Figure 15-5 illustrates the resulting 12-class (1P7Q1T+DBL) egress queuing model for the Catalyst 4500.

Figure 15-5

Figure 15-5 Catalyst 4500 12-Class (1P7Q1T+DBL) Egress Queuing Model

Example 15-3 shows the corresponding configuration for 12-class (1P7Q1T+DBL) egress queuing on the Catalyst 4500.

Example 15-3 Twelve-Class (1P7Q1T+DBL) Egress Queuing Configuration Example on a Catalyst 4500

 ! This section configures the class maps for the egress queuing policy
C4500(config)# class-map match-any PRIORITY-QUEUE
C4500(config-cmap)# match dscp ef
C4500(config-cmap)# match dscp cs5
C4500(config-cmap)# match dscp cs4
 ! VoIP (EF), Broadcast Video (CS5) and Realtime Interactive (CS4)
 ! are all mapped to the PQ
C4500(config)# class-map match-any CONTROL-MGMT-QUEUE
C4500(config-cmap)# match dscp cs7
C4500(config-cmap)# match dscp cs6
C4500(config-cmap)# match dscp cs3
C4500(config-cmap)# match dscp cs2
 ! Network Control (CS7), Internetwork Control (CS6),
 ! Signaling (CS3) and Management (CS2) are mapped
 ! to a Control/Management Queue
C4500(config)# class-map match-all MULTIMEDIA-CONFERENCING-QUEUE
C4500(config-cmap)# match dscp af41 af42 af43
 ! Multimedia Conferencing (AF4) is assigned a dedicated queue
C4500(config)# class-map match-all MULTIMEDIA-STREAMING-QUEUE
C4500(config-cmap)# match dscp af31 af32 af33
 ! Multimedia Streaming (AF3) is assigned a dedicated queue
C4500(config)# class-map match-all TRANSACTIONAL-DATA-QUEUE
C4500(config-cmap)# match dscp af21 af22 af23
 ! Transactional Data (AF2) is assigned a dedicated queue
C4500(config)# class-map match-all BULK-DATA-QUEUE
C4500(config-cmap)# match dscp af11 af12 af13
 ! Bulk Data (AF1) is assigned a dedicated queue
C4500(config)# class-map match-all SCAVENGER-QUEUE
C4500(config-cmap)# match dscp cs1
 ! Scavenger (CS1) is assigned a dedicated queue


 ! This section configures the 1P7Q1T+DBL egress queuing policy map
C4500(config)# policy-map 1P7Q1T
C4500(config-pmap-c)# class PRIORITY-QUEUE
C4500(config-pmap-c)#  priority
 ! Defines a priority queue
C4500(config-pmap-c)# class CONTROL-MGMT-QUEUE
C4500(config-pmap-c)#  bandwidth remaining percent 10
 ! Defines a control/management queue with 10% BW remaining
C4500(config-pmap-c)# class MULTIMEDIA-CONFERENCING-QUEUE
C4500(config-pmap-c)#  bandwidth remaining percent 10
C4500(config-pmap-c)#  dbl
 ! Defines a multimedia conferencing queue with 10% BW remaining + DBL
C4500(config-pmap-c)# class MULTIMEDIA-STREAMING-QUEUE
C4500(config-pmap-c)#  bandwidth remaining percent 10
C4500(config-pmap-c)#  dbl
 ! Defines a multimedia streaming queue with 10% BW remaining + DBL
C4500(config-pmap-c)# class TRANSACTIONAL-DATA-QUEUE
C4500(config-pmap-c)#  bandwidth remaining percent 10
C4500(config-pmap-c)#  dbl
 ! Defines a transactional data queue with 10% BW remaining + DBL
C4500(config-pmap-c)# class BULK-DATA-QUEUE
C4500(config-pmap-c)#  bandwidth remaining percent 4
C4500(config-pmap-c)#  dbl
 ! Defines a bulk data queue with 10% BW remaining + DBL
C4500(config-pmap-c)# class SCAVENGER-QUEUE
C4500(config-pmap-c)#  bandwidth remaining percent 1
 ! Defines a (minimal) scavenger queue with 1% BW remaining/limit
C4500(config-pmap-c)# class class-default
C4500(config-pmap-c)#  bandwidth remaining percent 25
C4500(config-pmap-c)#  dbl
 ! Provisions the default/Best Effort queue with 25% BW remaining + DBL


 ! This section attaches the egress queuing policy to the interface(s)
C4500(config)# interface range TenGigabitEthernet 1/1-2
C4500(config-if-range)# service-policy output 1P7Q1T

You can verify the configuration in Example 15-3 with the following commands:

  • show class-map
  • show policy-map
  • show policy-map interface (as shown in Example 15-4)

Example 15-4 Verifying Queuing Policies on a Catalyst 4500: show policy-map interface

C4500# show policy-map interface TenGigabitEthernet 1/1
 TenGigabitEthernet1/1
  Service-policy output: 1P7Q1T

    Class-map: PRIORITY-QUEUE (match-any)
      102598 packets
      Match:  dscp ef (46)
        102598 packets
      Match:  dscp cs5 (40)
        0 packets
      Match:  dscp cs4 (32)
        0 packets
      priority queue:
          Transmit: 22782306 Bytes, Queue Full Drops: 0 Packets

    Class-map: CONTROL-MGMT-QUEUE (match-any)
      24847 packets
      Match:  dscp cs7 (56)
        0 packets
      Match:  dscp cs6 (48)
        0 packets
      Match:  dscp cs3 (24)
        24847 packets
      Match:  dscp cs2 (16)
        0 packets
      bandwidth remaining 10 (%)
          Transmit: 24909844 Bytes, Queue Full Drops: 0 Packets


    Class-map: MULTIMEDIA-CONFERENCING-QUEUE (match-all)
      22280511 packets
      Match:  dscp af41 (34) af42 (36) af43 (38)
      bandwidth remaining 10 (%)
          Transmit: 4002626800 Bytes, Queue Full Drops: 0 Packets
      dbl
          Probabilistic Drops: 0 Packets
          Belligerent Flow Drops: 0 Packets


    Class-map: MULTIMEDIA-STREAMING-QUEUE (match-all)
      0 packets
      Match:  dscp af31 (26) af32 (28) af33 (30)
      bandwidth remaining 10 (%)
          Transmit: 0 Bytes, Queue Full Drops: 0 Packets
      dbl
          Probabilistic Drops: 0 Packets
          Belligerent Flow Drops: 0 Packets


    Class-map: TRANSACTIONAL-DATA-QUEUE (match-all)
      235852 packets
      Match:  dscp af21 (18) af22 (20) af23 (22)
      bandwidth remaining 10 (%)
          Transmit: 247591260 Bytes, Queue Full Drops: 0 Packets
      dbl
          Probabilistic Drops: 0 Packets
          Belligerent Flow Drops: 0 Packets


    Class-map: BULK-DATA-QUEUE (match-all)
      2359020 packets
      Match:  dscp af11 (10) af12 (12) af13 (14)
      bandwidth remaining 4 (%)
          Transmit: 2476460700 Bytes, Queue Full Drops: 0 Packets
      dbl
          Probabilistic Drops: 0 Packets
          Belligerent Flow Drops: 0 Packets


    Class-map: SCAVENGER-QUEUE (match-all)
      78607323 packets
      Match:  dscp cs1 (8)
      bandwidth remaining 1 (%)
          Transmit: 98144078642 Bytes, Queue Full Drops: 26268 Packets


    Class-map: class-default (match-any)
      12388183 packets
      Match: any
        12388183 packets
      bandwidth remaining 25 (%)
          Transmit: 13001465825 Bytes, Queue Full Drops: 0 Packets
      dbl
          Probabilistic Drops: 0 Packets
          Belligerent Flow Drops: 0 Packets
C4500#

Example 15-4 shows various queuing classes and their associated packet and byte counts, including 26,268 queuing drops noted on the scavenger queue.

4. Additional Platform-Specific QoS Design Options | Next Section Previous Section

Cisco Press Promotional Mailings & Special Offers

I would like to receive exclusive offers and hear about products from Cisco Press and its family of brands. I can unsubscribe at any time.

Overview

Pearson Education, Inc., 221 River Street, Hoboken, New Jersey 07030, (Pearson) presents this site to provide information about Cisco Press products and services that can be purchased through this site.

This privacy notice provides an overview of our commitment to privacy and describes how we collect, protect, use and share personal information collected through this site. Please note that other Pearson websites and online products and services have their own separate privacy policies.

Collection and Use of Information

To conduct business and deliver products and services, Pearson collects and uses personal information in several ways in connection with this site, including:

Questions and Inquiries

For inquiries and questions, we collect the inquiry or question, together with name, contact details (email address, phone number and mailing address) and any other additional information voluntarily submitted to us through a Contact Us form or an email. We use this information to address the inquiry and respond to the question.

Online Store

For orders and purchases placed through our online store on this site, we collect order details, name, institution name and address (if applicable), email address, phone number, shipping and billing addresses, credit/debit card information, shipping options and any instructions. We use this information to complete transactions, fulfill orders, communicate with individuals placing orders or visiting the online store, and for related purposes.

Surveys

Pearson may offer opportunities to provide feedback or participate in surveys, including surveys evaluating Pearson products, services or sites. Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites; develop new products and services; conduct educational research; and for other purposes specified in the survey.

Contests and Drawings

Occasionally, we may sponsor a contest or drawing. Participation is optional. Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing. Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law.

Newsletters

If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information@ciscopress.com.

Service Announcements

On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.

Customer Service

We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.

Other Collection and Use of Information

Application and System Logs

Pearson automatically collects log data to help ensure the delivery, availability and security of this site. Log data may include technical information about how a user or visitor connected to this site, such as browser type, type of computer/device, operating system, internet service provider and IP address. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources.

Web Analytics

Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site. While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson (but not the third party web trend services) to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.

Cookies and Related Technologies

This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site.

Do Not Track

This site currently does not respond to Do Not Track signals.

Security

Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.

Children

This site is not directed to children under the age of 13.

Marketing

Pearson may send or direct marketing communications to users, provided that

  • Pearson will not use personal information collected or processed as a K-12 school service provider for the purpose of directed or targeted advertising.
  • Such marketing is consistent with applicable law and Pearson's legal obligations.
  • Pearson will not knowingly direct or send marketing communications to an individual who has expressed a preference not to receive marketing.
  • Where required by applicable law, express or implied consent to marketing exists and has not been withdrawn.

Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider. Marketing preferences may be changed at any time.

Correcting/Updating Personal Information

If a user's personally identifiable information changes (such as your postal address or email address), we provide a way to correct or update that user's personal data provided to us. This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service@informit.com and we will process the deletion of a user's account.

Choice/Opt-out

Users can always make an informed choice as to whether they should proceed with certain services offered by Cisco Press. If you choose to remove yourself from our mailing list(s) simply visit the following page and uncheck any communication you no longer want to receive: www.ciscopress.com/u.aspx.

Sale of Personal Information

Pearson does not rent or sell personal information in exchange for any payment of money.

While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest@pearson.com.

Supplemental Privacy Statement for California Residents

California residents should read our Supplemental privacy statement for California residents in conjunction with this Privacy Notice. The Supplemental privacy statement for California residents explains Pearson's commitment to comply with California law and applies to personal information of California residents collected in connection with this site and the Services.

Sharing and Disclosure

Pearson may disclose personal information, as follows:

  • As required by law.
  • With the consent of the individual (or their parent, if the individual is a minor)
  • In response to a subpoena, court order or legal process, to the extent permitted or required by law
  • To protect the security and safety of individuals, data, assets and systems, consistent with applicable law
  • In connection the sale, joint venture or other transfer of some or all of its company or assets, subject to the provisions of this Privacy Notice
  • To investigate or address actual or suspected fraud or other illegal activities
  • To exercise its legal rights, including enforcement of the Terms of Use for this site or another contract
  • To affiliated Pearson companies and other companies and organizations who perform work for Pearson and are obligated to protect the privacy of personal information consistent with this Privacy Notice
  • To a school, organization, company or government agency, where Pearson collects or processes the personal information in a school setting or on behalf of such organization, company or government agency.

Links

This web site contains links to other sites. Please be aware that we are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of each and every web site that collects Personal Information. This privacy statement applies solely to information collected by this web site.

Requests and Contact

Please contact us about this Privacy Notice or if you have any requests or questions relating to the privacy of your personal information.

Changes to this Privacy Notice

We may revise this Privacy Notice through an updated posting. We will identify the effective date of the revision in the posting. Often, updates are made to provide greater clarity or to comply with changes in regulatory requirements. If the updates involve material changes to the collection, protection, use or disclosure of Personal Information, Pearson will provide notice of the change through a conspicuous notice on this site or other appropriate way. Continued use of the site after the effective date of a posted revision evidences acceptance. Please contact us if you have questions or concerns about the Privacy Notice or any objection to any revisions.

Last Update: November 17, 2020