HP HPE6-A47 - Designing Aruba Solutions

The Aruba MC 7010 and 7024 are both designed for small to mid-sized campuses and branches, but they have some differences in their features and specifications. One of the main differences is the number and type of ports they offer. The MC 7010 has 16 10/100/1000BASE-T ports, while the MC 7024 has 8 10/100/1000BASE-T ports and 8 1000BASE-X SFP ports1. This means that the MC 7024 can support more APs that require fiber connections, such as the AP-387 or the AP-5352. The MC 7024 also supports 10G ports, which can provide higher bandwidth and performance for the network backbone3.

Therefore, if the customer needs to connect 20 APs directly to the MC, and some of them require fiber or 10G connections, the MC 7024 is a better choice than the MC 7010. The other options (A, B, and C) are not relevant for choosing between the MC 7010 and 7024, as both models can support up to 64 APs and 4096 users or devices, and both models can provide PoE+ on 12 ports1.

References:

Aruba 7000 Series Mobility Controllers Data Sheet

Aruba Access Points Data Sheet

Aruba 7000 Series Mobility Controllers and Gateways

The minimum acceptable signal for an active site survey depends on the type of applications and the data rates that the users require. For 802.11ac, which operates in the 5 GHz band, Aruba recommends a signal of -65 dBm or better for high-performance applications such as voice and video, and a signal of -72 dBm or better for basic applications such as Web and email1. These values are based on the receiver sensitivity of typical 802.11ac clients and the expected signal-to-noise ratio (SNR) for different modulation and coding schemes (MCS). A higher SNR means a higher data rate and a better user experience.

Therefore, the architect should look for a signal of -65 dBm in the 5 GHz band to determine the test AP range for 802.11ac, assuming that the users run high-performance applications. A signal of -75 dBm in the 5 GHz band might be too weak to support the desired data rates and quality of service. A signal of -65 dBm or -75 dBm in the 2.4 GHz band is irrelevant for 802.11ac, as it does not operate in that band.

References:

Aruba Validated Reference Design: 802.11ac Networks

Best Practices for Monitoring and Troubleshooting 802.11ac Networks

DSCP (Differentiated Services Code Point) is a method of marking network packets with different priorities based on the type of traffic they carry. DSCP values range from 0 to 63, with higher values indicating higher priority. DSCP values are typically mapped to one of the four WMM (Wi-Fi Multimedia) queues, which are used to prioritize wireless traffic on the access points and controllers. WMM queues are: voice, video, best effort, and background12.

The default QoS settings for Aruba APs and controllers map the DSCP values to the WMM queues as follows3:

Table

DSCP Value

WMM Queue

0-7

Background

8-23

Best Effort

24-39

Video

40-63

Voice

According to these settings, the DSCP values 46 and 34, which are assigned to voice and video traffic by Windows policies, will both be mapped to the video WMM queue. This means that both types of traffic will receive the same priority, and voice traffic will not receive the highest priority that it should. This can result in poor voice quality, increased latency, jitter, or packet loss, especially when the network is congested or bandwidth is limited. Voice traffic is more sensitive to these factors than video traffic, and requires strict QoS to ensure optimal performance and user experience4.

To avoid this potential issue, the architect should explain to the customer that they need to modify the QoS settings on the Aruba APs and controllers to match the DSCP values assigned by Windows policies. This can be done by using the following commands on the Aruba controller3:

(config) #wmm traffic-management-profile voice

(config) #dscp 46

(config) #wmm traffic-management-profile video

(config) #dscp 34

These commands will map the DSCP value 46 to the voice WMM queue, and the DSCP value 34 to the video WMM queue, ensuring that voice traffic receives the highest priority and video traffic receives the second highest priority. This will improve the QoS for the Skype for Business UC solution and enhance the end-user experience.

References:

1: https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/1-overview/qos.htm

2: https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/1-overview/wmm.htm

3: https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/1-overview/qos-mapping.htm

4: https://www.arubanetworks.com/techdocs/ArubaOS_86_Web_Help/Content/arubaos-solutions/1-overview/qos-voice.htm

The Aruba 2930F Switch Series is a stackable Layer 3 switch series that provides performance and ease of use for enterprises, small and medium-sized businesses, and branch office networks1. It comes with an enterprise-grade feature set that includes static and RIP routing, IPv6, ACLs, robust security, and QoS1. The 2930F Series supports more options for class-based Quality of Service (QoS) policies than the 2540 Series2. This feature is crucial for a customer who needs a wired network solution that can recognize and prioritize a wide array of different types of traffic, including casual Web browsing, voice, video, SAP Online, and file sharing.

References:

HPE Aruba Networking 2930F Switch Series

Why would the architect choose the 2930F rather than the 2540 Switch Series for this customer?

This is a routed link, meaning you should only have one VLAN assigned to the link. Obvious since VLANs are terminated at a layer 3 boundary, but also right out of the curriculum.

References: The information can be referenced from the official HPE documents and learning materials available on HPE Press and Aruba Networks. Specifically, it aligns with the objectives outlined in Chapter 5: Wired Network Design, where the VSF and VLAN design considerations are discussed. Designing Aruba Solutions Official Certification Study Guide ArubaOS-Switch and ArubaOS-CX VSF Configuration Guide

ClearPass Access licenses are required for each unique endpoint that authenticates to ClearPass using any supported protocol, such as 802.1X, MAC authentication, web authentication, or VPN authentication1. ClearPass Onboard licenses are required for each unique endpoint that is provisioned with a certificate using the ClearPass Onboard service2. In this scenario, the customer has 900 employees and up to 30 guests a day, which means there are at most 930 users who need to authenticate to the network. Assuming each user has about two or three devices, the maximum number of devices that need Access licenses is 930 x 3 = 2790, which can be rounded up to 3000. The customer also wants to use certificates to authenticate user devices, which means they need Onboard licenses as well. However, the customer only issues laptops to the employees, which means only 900 devices need Onboard licenses. Therefore, the architect should include 3000 Access licenses and 1000 Onboard licenses in the proposal. References:

1: ClearPass Licensing Guide - Aruba

2: ClearPass Onboard Data Sheet - Aruba

 The number of devices used by each user is an important factor for creating the RF plan, as it affects the network capacity, bandwidth demand, and interference level. The architect should estimate the average number of devices per user and the types of applications they use, such as voice, video, or data. This will help the architect to determine the optimal number and placement of access points, the channel width and selection, the transmit power and data rates, and the radio resource management settings.

The OS used on wireless devices, whether BLE wayfinding is required, and the software version on MCs are not directly relevant for creating the RF plan, as they do not affectthe physical layer characteristics of the wireless network. However, they may have implications for other aspects of the network design, such as security, compatibility, and features.

References:

RF Design | Validated Solution Guide - Aruba

Enterprise Mobility 8.5 Design Guide - WLAN RF Design Considerations [Cisco 5500 Series Wireless Controllers] - Cisco

This is the general recommendation from the AirWave Server Sizing Guide1, which provides guidelines for selecting and configuring hardware based on the number of devices, clients, and features. The guide also lists the conditions that impact hardware sizing, such as polling frequency, RAPIDS, VisualRF, and Clarity.

References: 1: AirWave 8.2.14.0 Server Sizing Guide - Aruba, page 5.

Deployed as a purpose-built hardware or virtual machine image, each AirWave server supports up to 4,000 network devices (access points, switches, and controllers).https://www.arubanetworks.com/assets/ds/DS_AW.pdf

it meets the customer’s requirements for wired network upgrade. By combining the switches in each Building 2 closet as a Virtual Switching Framework (VSF) fabric, the architect can reduce the number of logical devices within the network, simplifying management and reducing complexity, aligning with the goal of flattening architecture. Establishing two 10 GbE connections to the core per fabric ensures redundancy and resilience, maintaining connectivity even if one link fails, without necessitating additional cabling. This also provides sufficient bandwidth and scalability for the network traffic.

The other options are incorrect because:

A. Using two additional 2930F switches to act as an aggregation layer for Building 2 adds another layer of devices and complexity to the network, contradicting the goal of flattening architecture. It also requires additional cabling and ports to connect the switches to the core and the access layer.

B. Connecting each Building 2 switch directly to the core on a single fiber strand through the use of SFP±SR transceivers does not provide redundancy and resilience, as one link failure would disconnect the switch from the core. It also limits the bandwidth and scalability of the network, as each switch would have only one 10 GbE connection to the core.

D. Extending additional fiber between the buildings so that each Building 2 switch can have a direct 10 GbE connection to the core requires recabling, which the customer wants to avoid. It also increases the cost and complexity of the network, as more fiber strands and ports would be needed.

References:

Aruba 2930M Switch Series - Data sheet)

Aruba Validated Reference Design: Campus Wired LAN - Chapter 3)

ArubaOS-Switch Virtual Switching Framework - Configuration guide)