Best Practice Design - MR Wireless

Capacity Planning

Once the above mentioned details are available, capacity planning can then be broken down into the following phases:

• Estimate Aggregate Application Throughput

• Estimate Device Throughput

• Estimate Number of APs

Calculating the number of access points necessary to meet a site's bandwidth needs is the recommended way to start a design for any high density wireless network.

Mounting Access Points

The two main strategies for mounting Cisco Meraki access points are ceiling mounted and wall mounted. Each mounting solution has advantages.

Ceiling mounted MR, Cisco San Francisco

Ceiling mounted access points are placed on a ceiling tile, T-bar, roof, or conduit extending down from the roof. This brings advantages such as a clear line-of-sight to the user devices below and flexibility in where to place the access point. Access points can be easily placed with even spacing in a grid and at the intersection of hallways. The disadvantage is the ceiling height and the height of the access point could negatively impact the coverage and capacity.

• If access points have to be installed below 8 feet (~3 meters), indoor access points with integrated omni antennas or external dipole/can omni antennas are recommended.

• If access points have to be installed between 8 - 25 feet (3 - 8 meters), indoor access points with external downtilt omni antennas are recommended.

Wall mounted MRs, Cisco San Francisco

When ceiling heights are too high (25+ feet) or not feasible to mount access points (hard ceiling), a wall mounted design is recommended. The access points are mounted on drywall, concrete or even metal on the exterior and interior walls of the environment.  Access points are typically deployed 10-15 feet (3-5 meters) above the floor facing away from the wall. Remember to install with the LED facing down to remain visible while standing on the floor. Designing a network with wall mounted omnidirectional APs should be done carefully and should be done only if using directional antennas is not an option. 

Pole mounted MR66 with Sector antennas, Cisco San Francisco

Directional Antennas

If there is no mounting solution to install the access point below 26 feet (8 meters), or where ceilings are replaced by the stars and the sky (outdoors), or if directional coverage is needed it is recommend to use directional antennas. When selecting a directional antenna, you should compare the horizontal/vertical beam-width and gain of the antenna.

When using directional antennas on a ceiling mounted access point, direct the antenna pointing straight down. When using directional antennas on a wall mounted access point, tilt the antenna at an angle to the ground. Further tilting a wall mounted antenna to pointing straight down will limit its range.

Cisco Meraki offers 6 types of indoor-rated external antennas (available for MR42E and MR53E):

Cisco Meraki offers 4 types of outdoor external antennas and supports 5 types of outdoor antennas. Cisco Meraki has certified the antennas for use with the Meraki MR84, MR74, MR72, MR66, and MR62 access points. AIR-ANT2514-P4M can only be used with MR84: 

Access Point Placement

Once the number of access points has been established, the physical placement of the AP’s can then take place. A site survey should be performed not only to ensure adequate signal coverage in all areas but to additionally assure proper spacing of APs onto the floorplan with minimal co-channel interference and proper cell overlap. It’s very important to consider the RF environment and construction materials used for AP placement.

Review the designs below from the Cisco Meraki San Francisco office. The 4th Floor was constructed to support Cisco's sales team, customer briefings, and a cafe. In contrast, the 3rd floor was constructed to support Cisco's 24x7 technical support, our small IT department, and Cisco's Collaboration group with applications such as Telepresence and Cisco Spark HD video chat. The density of the 3rd floor is double that of the 4th floor.

High density with 30 access points, Cisco San Francisco, 4th Floor

Ultra High density with 60 access points, Cisco San Francisco, 3rd Floor

Number of SSIDs 

The maximum recommended number of SSIDs is 3, and in a high-density environment, this recommendation becomes a requirement. If needed, the number of SSIDs can be increased to 5 but should be done only when necessary.  Using more than 5 SSIDs creates substantial airtime overhead from management frames: consuming 20% or more of the bandwidth available and limiting the maximum throughput to less than 80% of the planned capacity. Create a separate SSID for each type of authentication required (Splash, PSK, EAP) and consolidate any SSIDs that use the same type authentication.

Enable Bridge Mode

Bridge mode is recommended to improve roaming for voice over IP clients with seamless Layer 2 roaming. In bridge mode, the Meraki APs act as bridges, allowing wireless clients to obtain their IP addresses from an upstream DHCP server. Bridge mode works well in most circumstances, provides seamless roaming with the fastest transitions. When using Bridge mode, all APs in the intended area (usually a floor or set of APs in an RF Profile) should support the same VLAN to allow devices to roam seamlessly between access points.

For seamless roaming in bridge mode, the wired network should be designed to provide a single wireless VLAN across a floor plan. If the network requires a user to roam between different subnets, using L3 roaming is recommended. Bridge mode will require a DHCP request when roaming between two subnets or VLANs. During this time, real-time video and voice calls will noticeably drop or pause, providing a degraded user experience.

Layer 3 Roaming

Large wireless networks that need roaming across multiple VLANs may require layer 3 roaming to enable application and session persistence while a mobile client roams. With layer 3 roaming enabled, a client device will have a consistent IP address and subnet scope as it roams across multiple APs on different VLANs/subnets.

Cisco Meraki's Layer 3 roaming is a distributed, scalable way for Access Points to establish connections with each other without the need for a controller or concentrator. The first access point that a device connects to will become the anchor Access Point. The anchor access point informs all of the other Cisco Meraki access points within the network that it is the anchor for a particular client. Every subsequent roam to another access point will place the device/user on the VLAN that defined by the anchor AP. This is ideal for high-density environments that require Layer 3 roaming, and there is no throughput limitation on the network.

The MR continues to support Layer 3 roaming to a concentrator requires an MX security appliance or VM concentrator to act as the mobility concentrator. Clients are tunneled to a specified VLAN at the concentrator, and all data traffic on that VLAN is now routed from the MR to the MX. The concentrator creates a choke-point, and in a high-density environment, the number of clients may be limited by the throughput of the MX concentrator.

Band Selection

If the client devices require 2.4 GHz, enable 'Dual-band with band steering' to enable client devices to use both 2.4 GHz channels and 5 GHz. Devices will be steered to use the 5 GHz band. For more details refer to the Band Steering Overview article. With a dual-band network, client devices will be steered by the network. If 2.4 GHz support is not needed, it is recommended to use “5 GHz band only”. Testing should be performed in all areas of the environment to ensure there are no coverage holes.

Using RF Profiles, minimum bit rate can be set on a per band or a per SSID basis. For high-density networks, it is recommended to use minimum bit rates per band. If legacy 802.11b devices need to be supported on the wireless network, 11 Mbps is recommended as the minimum bitrate on 2.4 GHz. Adjusting the bitrates can reduce the overhead on the wireless network and improve roaming performance. Increasing this value requires proper coverage and RF planning. An administrator can improve the performance of clients on the 2.4 GHz and 5 GHz band by disabling lower bitrates. Management frames will be sent out at the lowest selected rate. Clients must use either the lowest selected rate or a faster one. Selecting a Minimum bitrate of 12Mbps or greater will prevent 802.11b clients from joining and will increase the efficiency of the RF environment by sending broadcast frames at a higher bitrate.

RX-SOP

Using RX-SOP, the receive sensitivity of the AP can be controlled. The higher the RX-SOP level, the less sensitive the radio is and the smaller the receiver cell size will be. The reduction in cell size ensures that the clients are connected to the nearest access point using the highest possible data rates. In a high density environment, the smaller the cell size, the better. This should be used with caution however as you can create coverage area issues if this is set too high. It is best to test/validate a site with varying types of clients prior to implementing RX-SOP in production.

 

 

 

The table below gives the recommended values for RX-SOP in high density deployments:

802.11 Band	High Threshold	Medium Threshold	Low Threshold
5 GHz	-76 dBm	-78 dBm	-80 dBm
2.4 GHz	-79 dBm	-82 dBm	-85 dBm

Note: RX-SOP is supported on 802.11 ac Wave 2 and 802.11 ax APs i.e. MR30H/33/42/52/53/74/84/42E/53E/45/55

Set Bandwidth Limits 

Consider placing a per-client bandwidth limit on all network traffic. Prioritizing applications such as voice and video will have a greater impact if all other applications are limited. For more details refer to the article Configuring Bandwidth Limitations and Enabling Speed Burst on Wireless Networks. 5 Mbps is a good recommendation for per-client bandwidth limit in high-density environment. You can override this limit for specific devices and applications.

1. Go to Wireless > Configure > Firewall & traffic shaping and choose the SSID from the SSID drop-down menu at the top of the screen.
2. Set a 'Per-client bandwidth limit' to 5 Mbps with 'Speed Burst'. This will apply to all non-voice application traffic. This step in the guide is optional. 
3. Set a 'Per-SSID bandwidth limit' to unlimited.

Define Traffic Shaping Rules

Use traffic shaping to offer application traffic the necessary bandwidth. It is important to ensure that the application has enough bandwidth as estimated in the capacity planning section. Traffic shaping rules can be implemented to allow real-time voice and video traffic to use additional bandwidth, and the rules can be used to block or throttle applications such as P2P, social networks. 

1. Go to Wireless > Configure > Firewall & traffic shaping and choose the SSID from the SSID drop-down menu at the top of the screen.
2. Click the drop down menu next to Shape traffic and choose Shape traffic on this SSID, then click Create a new rule.
3. Click Add + and select 'All voice & video conferencing' 
4. Set Per-client bandwidth limit to 'Ignore SSID per-client limit (unlimited)' and click Save changes.

Convert Multicast to Unicast

Cisco Meraki APs automatically perform a multicast-to-unicast packet conversion using the IGMP protocol. The unicast frames are then sent at the client negotiated data rates rather than the minimum mandatory data rates, ensuring high-quality video transmission to large numbers of clients. This can be especially valuables in instances such as classrooms, where multiple students may be watching a high-definition video as part a classroom learning experience. 

Limit Broadcasts 

Broadcast Domain Mapping

Each Meraki Access point sends layer 2 broadcast probes over the Ethernet uplink to discover broadcast domain boundaries on each VLAN that a client could be associated with when connected. This is done for multiple reasons. One reason is because there can be instances where AP1 is connected to an access port (no VLAN tag) and AP2 is connected to a trunk port where the same VLAN is used, but the VLAN ID is present and tagged on the uplink. These broadcast frames are of type 0x0a89 sent every 150 seconds.

There could also be situations where the same VLAN ID is used in different buildings (representing different broadcast domains), so it’s important to ensure exactly which APs and VLAN IDs can be found on which broadcast domains. Apart from tunnel load balancing and resiliency, the broadcast domain mapping and discovery process also allows for anchor APs and hosting APs to have a real-time view into which VLANs are shared between the two APs. This allows for efficient decision making when it comes to layer 2 vs layer 3 roaming for a client, as described in the “VLAN Testing and Dynamic Configuration” section below.  This is important so that anchor APs for clients can be dynamically switched for load balancing reasons, or in failover situations where the original anchor AP is no longer available. 
Meraki APs will send out probes to discover the following broadcast domains:

• The AP’s native VLAN
• Any VLAN that is configured for the SSID on the AP
• Any VLAN that is dynamically learned via a client policy 
• Any VLAN that an AP has recently received a broadcast probe on from another Meraki AP in Dashboard network

The power of the broadcast domain mapping is that this will discover broadcast domains agnostic of VLAN IDs configured on an AP. As a result of this methodology, each AP on a broadcast domain will eventually gather exactly the AP/VLAN ID pairs that currently constitute the domain. Whenever a client connects to another SSID the Anchor AP for that client is updated.

Broadcast Domain Discovery

The following steps establish the AP/VLAN ID (VID) pair that correspond to a broadcast domain:

1. APs periodically broadcast a BCD announcement packet that contains the AP’s VLAN ID for that broadcast domain, giving a {sender AP,VID} pair on each broadcast domain the AP interacts with.
2. Create equivalence classes based on AP/VID pairs recently observed in BCD announcement packets on the same broadcast domain.

Additional notes:

• Each AP on a broadcast domain will eventually gather exactly the AP/VID pairs that currently constitute the domain.
• In principle, any AP/VID pair can be used to refer to a broadcast domain. Given AP1/VID1, as long as you know the full list of pairs for that broadcast domain, you can tell whether some other AP2/VID2 refers to the same domain or not.

An AP could theoretically broadcast BCD announcement packets to all 4095 potentially attached VLANs, however it will limit itself to the VLANs outlined above.

Roaming with Broadcast Domains

The Meraki MRs leverage a distributed client database to allow for efficient storage of clients seen in the network and to easily scale for large networks where thousands of clients may be connecting. The client distributed database is accessed by APs in real-time to determine if a connecting client has been seen previously elsewhere in the network. This requires that the APs in the Meraki network have layer 3 IP connectivity with one another, communicating over UDP port 9358. Leveraging the Meraki Dashboard, the APs are able to dynamically learn about the other APs in the network (including those located on different management VLANs) to know whom they should communicate with to look up clients in the distributed client database. 
 

The following process describes how client roaming operates with distributed layer 3 roaming

1. Anchor APs have a full set of AP/VLAN ID pairs for each attached broadcast domain as described above.

2. On client association, the hosting AP retrieves the client data from the distributed store.

   • If the hosting AP does not find an entry in the store:

     • The hosting AP then becomes the anchor AP for the client. It stores the client in the distributed database, adding a candidate anchor AP set. The candidate anchor set consists of the AP’s own AP/VLAN ID pair plus two randomly chosen pairs from the same anchor broadcast domain.

   • If the hosting AP does find an entry in the store:

     • It checks to see if the client’s VLAN is available locally, from the previous broadcast domain discovery process outlined above. If the associated VLAN ID is available, the hosting AP will become the anchor AP and the VLAN for that client will dynamically be provisioned for the client. See the section “VLAN Testing and Dynamic Configuration” below.

     • Otherwise, the hosting AP sets up an anchor AP for the client (picking a random pair from the candidate anchor set).

3. As long as the hosting AP continues to host the client, it periodically receives updates to the candidate anchor set from the anchor AP. The anchor AP replaces any AP/VLAN ID pair in the candidate anchor set that disappears with another randomly chosen AP/VLAN ID pair for that broadcast domain. The hosting AP updates the distributed store’s client entry with changes to the candidate

VLAN Testing and Dynamic Configuration

The anchor access point runs a test to the target access point to determine if there is a shared layer 2 broadcast domain for every client serving VLAN. If there is a VLAN match on both access points, the target access point will configure the device for the VLAN without establishing a tunnel to the anchor. This test will dynamically configure the VLAN for the roaming device despite the VLAN that is configured for the target access point and the clients served by it. If the VLAN is not found on the target AP either because it is pruned on the upstream switchport or the Access Point is in a completely separated layer 3 network, the Tunneling method described below will be used.

Tunneling

If necessary, the target access point will establish a tunnel to the anchor access point. Tunnels are established using Meraki-proprietary access point to access point communication. To load balance multiple tunnels amongst multiple APs, the tunneling selector will choose a random AP that has access to the original broadcast domain the client is roaming from. If the target AP detects a connectivity failure to the currently selected anchor AP, as a failover mechanism the target AP will choose a new anchor AP. Hosting AP will ping Anchor AP every second to ensure that the Anchor AP has not failed. This ping is integrated as a part of the L3 communication on UDP port 9358.
 
All APs must be able to communicate with each other via IP.  This is required both for client data tunneling and for the distributed database. If a target access point is unable to communicate with the anchor access point the layer 3 roam will time out and the end device will be required to DHCP on the new VLAN. Data packets are not encrypted between two Anchor APs on the wired side but control and management frames are encrypted.

Voice Quality Before this Guide

With the default settings on the MR, we see the baseline for quality. Voice calls with Lync on this network would be acceptable to some users, but not acceptable to others. The results of the Lync testing show that the Network Mean Opinion Score (MOS) drops below 3.5. Values values dropping below 3.5 are termed unacceptable by many users. The packet loss jumps to 8 percent during a period of network congestion simulated by running a speed test. Jitter fluctuates from 12 milliseconds to over 36 milliseconds. Cisco recommends a target of 10 ms of jitter and no more than 50 ms of jitter. Jitter is handled using buffering in voice/video applications, adding a small delay. The human ear normally accepts up to about 140 milliseconds of delay without noticing it.

Voice Quality After this Guide

After making the changes exactly as described in this guide, we see a significant improvement in voice quality. The MOS score approaches 3.9, the packet loss is near zero, and the jitter is consistently below 6 milliseconds and always below 12 milliseconds. As the call starts, traffic shaping kicks in automatically with prioritization and QoS tagging. A speed test was performed with no impact to the voice traffic - packet loss increased to 0.5% during the congestion.

Summary of 802.11 Standards

All Meraki MR series access points support the most recent 802.11 standards implemented to assist devices to roam between access points and ensure voice calls maintain a quality user experience. 

• 802.11r: Fast BSS transition to permit fast and secure hand-offs from one access point to the other in a seamless manner
• 802.11i: Enabling client devices authenticated via 802.1x to authenticate with decreased latency whilst roaming
• 802.11k: assisted roaming allows clients to request neighbor reports for intelligent roaming across access points.
• 802.11e: Wireless Multimedia Extensions (WMM) traffic prioritization ensures wireless VoIP phones receive higher priority.
• WMM Power Save: maximizes power conservation and battery life on devices without sacrificing Quality of Service.
• 802.11u: Hotspot 2.0 also known as Passpoint is a service provider feature that assists with carrier offload.

Add a Dedicated Voice SSID 

Voice optimization typically requires a different configuration including access control and traffic shaping to address device specific recommendations. You should create a separate Voice SSID for devices dedicated to voice applications. While this is not a requirement, we recommend to create a separate network to follow this guide. In networks with VoIP handsets from two different manufacturers, it is common to create two voice SSIDs. 

Authentication Type

Voice over WiFi devices are often mobile and moving between access points while passing voice traffic. The quality of the voice call is impacted by roaming between access points. Roaming is impacted by the authentication type. The authentication type depends on the device and it's supported auth types. It's best to choose the auth type that is the fastest and supported by the device. If your devices do not support fast roaming, Pre-shared key with WPA2 is recommended. ​WPA2-Enterprise without fast roaming can introduce delay during roaming due to its requirement for full re-authentication. When fast roaming is utilized with WPA2-Enterprise, roaming times can be reduced from 400-500 ms to less than 100 ms, and the transition time from one access point to another will not be audible to the user. The following list of auth types is in order of fastest to slowest.

1. Open (no encryption)
2. Pre-shared key with WPA2 and Fast roaming
3. WPA2-Enterprise with Fast roaming
4. ​Pre-shared key with WPA2 
5. ​WPA2-Enterprise 

WPA2 only for Encryption Mode

Voice devices can benefit from having a single type of encryption used. ​By default, SSIDs on Cisco Meraki access points that are configured as WPA2 will utilize a combination of both WPA1 TKIP and WPA2 AES encryption. WPA2 (AES) is recommended and required in order to utilize caching or fast roaming. The WPA encryption setting is SSID specific, and can be found on the Wireless > Configure > Access control page.

• If all Voice devices support WPA2, the 'WPA2 only' option is recommended for Voice over IP devices. 
• If the device does not support AES, it is also possible to force TKIP only. Please contact Cisco Meraki support to configure this option.

For step-by-step instructions on changing the WPA encryption mode, see our document on Setting a WPA Encryption Mode.

802.11r fast roaming

Enabling 802.11r is recommended to improve voice quality while roaming. The 802.11r standard was designed to improve VoIP and voice applications on mobile devices connected to Wi-Fi, in addition to or instead of cellular networks. When mobile devices roam from one area to another, they disassociate from one access point and reassociate to the next access point. Enabling 802.11r benefits VoIP devices by reducing the roaming time spent changing between access points. Some client devices are not compatible with Fast BSS Transition (802.11r). You may wish to check your devices for compatibility.

Layer 2 and Layer 3 Roaming 

Bridge mode is recommended to improve roaming for voice over IP clients with seamless Layer 2 roaming. In bridge mode, the Meraki APs act as bridges, allowing wireless clients to obtain their IP addresses from an upstream DHCP server. Bridge mode works well in most circumstances, particularly for seamless roaming, and is the simplest option to put wireless clients on the LAN. To configure the client IP assignment modes please refer to our document on SSID Modes for Client IP Assignment.

When using Bridge mode, all APs on the same floor or area should support the same VLAN to allow devices to roam seamlessly between access points. Using Bridge mode will require a DHCP request when performing a Layer 3 roam between two subnets. For example, when a user on a VoIP call roams between APs on different VLANs without layer 3 roaming, the user's session will be interrupted as the external server must re-establish communication with the client's new IP address. During this time, a VoIP call will noticeably drop for several seconds, providing a degraded user experience. 

Large wireless networks with multiple VLANS per floor may require IP session roaming at layer 3 to enable application and session persistence while a mobile client roams across multiple VLANs. With layer 3 roaming enabled, a client device will have a consistent IP address and subnet scope as it roams across multiple APs on different VLANs/subnets. If Layer 3 roaming is required on your network, please refer to our article on Layer 3 Roaming. 

Segregate Traffic on a Voice VLAN 

Voice traffic tends to come in large amounts of two-way UDP communication. Since there is no overhead on UDP traffic ensuring delivery, voice traffic is extremely susceptible to bandwidth limitations, clogged links, or even just non-voice traffic on the same line. Separating out your voice traffic allows it to function independently of other network traffic, and allows for more granular control over different types of traffic.

If a voice VLAN is specified on a Meraki MS switch, the port will accept tagged traffic on the voice VLAN. In addition, the port will send out LLDP and CDP advertisements recommending devices use that VLAN for voice traffic.  The VLAN tagged on the wireless access point should match the Voice VLAN on your wired network.  For more information, please visit the article on Configuring MS Access Switch for Standard VoIP deployment.

Band Selection

The 2.4 GHz band has only 3 channels that do not overlap, while the 5 GHz band has up to 19 individual channels in the US. A wireless network will provide the best quality of service for wireless voice when designed correctly to support 5 Ghz coverage for voice. This can be configured under Access Control > Wireless options > Band selection > '5 GHz band only'. After configuration, testing should be performed in all areas of your environment. If you do not have proper 5 GHz coverage after a post-install site survey, you can manually increase the power on the 5 GHz radio  in Radio Settings > Channel Planning. 

If you do not have a dedicated Voice SSID, enable 'Dual-band with band steering' to enable your voice devices to use both 2.4 GHz channels and 5 GHz. Devices will be steered to use the 5 GHz band. For more details refer to the Band Steering Overview article. With a dual-band network, client devices will be steered by the network. However,  to improve voice quality, please follow our guide on configuring wireless band preference on client devices.

If you have devices that only support a 2.4 GHz network such as 802.11bgn devices, please contact Meraki Support to enable a 2.4 GHz only network.

Minimum Bitrate

For Voice networks, 12 Mbps is recommended as the minimum bitrate. Increasing this value requires proper coverage in the RF planning. An administrator can improve the performance of clients on the 2.4 GHz and 5Ghz band by disabling lower bitrates. Adjusting the bitrates can reduce the overhead on the wireless network and also in some cases improve roaming performance. 

Bandwidth Limits

Consider placing a per-client bandwidth limit on the rest of your network traffic. Prioritizing voice will have a greater impact if all other applications are limited. For more details refer to the article Configuring Bandwidth Limitations and Enabling Speed Burst on Wireless Networks.

1. Go to Wireless > Configure > Firewall & traffic shaping and choose your SSID from the SSID drop down menu at the top of the screen.
2. Set a 'Per-client bandwidth limit' to 5 Mbps with 'Speed Burst'. This will apply to all non-voice application traffic. This step in the guide is optional. 
3. Set a 'Per-SSID bandwidth limit' to unlimited.

Traffic Shaping Rules

Use traffic shaping to offer voice traffic the necessary bandwidth. It is important to ensure that your voice traffic has enough bandwidth to operate. As such, traffic shaping rules can be implemented to allow voice traffic to use additional bandwidth, or limit other types of traffic to help prioritize voice traffic.

1. Go to Wireless > Configure > Firewall & traffic shaping and choose your SSID from the SSID drop down menu at the top of the screen.
2. Click the drop down menu next to Shape traffic and choose Shape traffic on this SSID, then click Create a new rule.
3. Click Add + and select 'All VoIP & video conferencing' 
4. Set Per-client bandwidth limit to 'Ignore SSID per-client limit (unlimited)' and click Save changes.​

​

PCP, DSCP, and WMM mapping

Many devices support Quality of Service (QoS) tags to maintain traffic priority across the network. Meraki MR access points support WMM to improve the performance of real-time data such as voice and video.  WMM improves the reliability of applications in progress by preventing oversubscription of bandwidth. WMM accomplished this by enhancing the prioritization of traffic using the access categories: voice, video, best effort, and background data. WMM has mapped values which can be found in this article. To configure correct mapping for PCP and DSCP values, the following steps should be followed:

1. Go to Wireless > Configure > Firewall & traffic shaping and choose your SSID from the SSID drop down menu at the top of the screen.
2. Under the traffic shaping rules, make sure Shape Traffic for this SSID is selected and that  there's a rule for All voice & video conferencing.
3. Set PCP to '6' or the setting recommended by your device/application vendor (Note that PCP values can only be changed if the SSID has VLAN tagging enabled. This ensures there's a field to which the CoS value can be written).
4. Set DSCP to 46 (EF - Expedited Forwarding, Voice) or the setting recommended by your device/application vendor.

If no DSCP values are configured, the default DSCP to WMM mapping will be used. The access point does the mapping between the LAN's Layer 2 priority and the radio's WMM class. Below is table showing the mapping between common traffic types and their respective markings:

* n as used in place for the drop indication of assured forwarding matches values 1-3.  

For QoS prioritization to work end to end, ensure that upstream networking equipment supports QoS prioritization as well. The PCP and DSCP tags applied on the wireless access point should match the wired network configuration to ensure end-to-end QoS. For more information, please visit the article on Configuring MS Access Switch for Standard VoIP deployment article.

Custom Traffic Shaping 

If your voice traffic does not match the built-in application signatures or is not listed, you can create your own signature for traffic shaping.

1. Add the IP and ports used by your servers hosting Microsoft Lync / Skype for Business, Jabber, Spark, or other voice application.
   1. In the Definition field click Add + and Custom expressions 
   2. In the text field, enter the IP address of each of your voice servers for example 172.16.1.123 or a range of server IPs 172.16.1.0/24
   3. Also, add your servers as source addresses by using the CIDR notation localnet:172.16.1.123/32 for an individual server, or localnet:172.16.1.0/24 for a range of IPs.
   4. Click the Add + button again when finished.
2. If you have a dedicated voice SSID and dedicated voice VLAN add the local subnet of the client devices.
   1. In the Definition field click Add + and Custom expressions 
   2. In the text field, enter localnet:192.168.0.1/16 indicating the source subnet of your client devices in CIDRnotation.
   3. Click the Add + button again when finished.
3. Set Per-client bandwidth limit to 'Ignore SSID per-client limit (unlimited)' and click Save changes.​

Microsoft Lync / Skype for Business

This section will provide guidance on how to implement QoS for Microsoft Lync and Skype for Business. Microsoft Lync is a widely deployed enterprise collaboration application which connects users across many types of devices. This poses additional challenges because a separate SSID dedicated to the Lync application may not be practical. When you install Microsoft Lync Server / Skype for Business, Quality of Service (QoS) will not be enabled for any devices used in your organization that use an operating system other than Windows. For more guidance on deploying Lync over Wi-Fi, please read Microsoft's deployment guide, Delivering Lync 2013 Real-Time Communications over Wi-Fi.

Meraki's deep packet inspection can intelligently identify Lync calls made on your wireless network and apply traffic shaping policies to prioritize the Lync traffic - using the SIP Voice protocol. In addition to the Meraki built-in signatures for Skype and SIP, you should also identify each Lync server by IP and any custom ports used by your Lync clients or servers. Follow these steps to configure your traffic shaping rules for Lync / Skype.

1. Go to Wireless > Configure > Firewall & traffic shaping and choose your SSID from the SSID drop down menu at the top of the screen.
2. Click the drop down menu next to Shape traffic and choose Shape traffic on this SSID, then click Create a new rule.
3. Consider setting a 'Per-client bandwidth limit' to 5 Mbps with 'Speed Burst'. This will apply to all non-voice application traffic
4. Set Per-client bandwidth limit to unlimited
5. Create a traffic shaping rule for All voice & video conferencing > 'Skype' and 'SIP (Voice)'
6. Set the Per-client bandwidth limit to 'Ignore SSID per-client limit (unlimited)' from the drop down.
7. Set PCP to '6'. The 802.1p parameter is no longer supported in Lync Server 2013. The parameter is still valid for backward compatibility with Microsoft Lync Server 2010; however, it has no effect on devices used with Lync Server 2013.
8. Set DSCP to '46 (EF - Expedited Forwarding, Voice)' 
9. Add 'Custom expressions' for the IP and ports used by your servers hosting Microsoft Lync / Skype for Business
   1. For Cloud-hosted Lync / Skype, add the domain names from the table below
   2. Add the Port numbers from the table below or your own list of assigned port numbers
   3. Add the IP address of each of your on-premise Lync servers
10. You can test that DSCP markings are applied using the Meraki packet capture tool. 

Cisco 7925G Phones

Cisco 7925G, 7925G-EX, and 7926G VoIP phones require specific settings to inter-operate with Meraki MR access points configured with WPA2-PSK association requirements. For more in-depth information on integrating Cisco 792xG with MR Access Points, see the Cisco Unified Wireless IP Phone 792xG + Cisco Meraki Wireless LAN Deployment Guide. 

1. Cisco recommends to set band selection to 5 GHz only.
2. Do not utilize the Dual band operation with Band Steering option. If the 2.4 GHz band needs to be used due to increased distance, select Dual band operation (2.4 GHz and 5 GHz) should be selected. 
3. Set the Minimum bitrate to 11 Mbps or higher. 
4. By default, Cisco Meraki access points currently tag voice frames marked with DSCP EF (46) as WMM UP 6 and call control frames marked with DSCP CS3 (24) as WMM UP 4.

Cisco Meraki access points will trust DSCP tags by default. Administrators should ensure that upstream QoS is in place and that the QoS markings outlined below are in place for the 7925 phones. To rewrite QoS tags for certain traffic types or source/destination, then create a traffic shaping rule as outlined in Custom Traffic Shaping above.

Below is the QoS and port information for voice and call control traffic used by the Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G. For a full list of ports and protocols used by Cisco phones refer to the Cisco Unified Communications Manager TCP and UDP Port Usage Guide.

Apple iPhones

Apple and Cisco have created partnership to better support iOS business users by optimizing Cisco and Meraki networks for iOS devices and apps. For more information on this partnership, please see Apple's website. Meraki's group policies can be easily configured to optimize Apple devices on a Meraki network. First create a group policy you would like to apply to Apple devices.

1. Browse to Network-wide > Configure > Group Policies, scroll down and click Add Group. 
2. Under traffic shaping, create a new rule, and add All VoIP & video conferencing
   1. Set the Per-client bandwidth limit to Ignore network per-client limit
   2. Set PCP to 6 (highest priority) and DSCP to 46 (EF - Expedited Forwarding, Voice). 
3. Create a second rule, and add All Video & music
   1. Set the Per-client bandwidth limit to Ignore network per-client limit
   2. Set PCP to 5 and DSCP to 34 (AF41- Multimedia Conferencing, Low Drop).

To apply your new Apple device group policy, browse to Wireless > Access Control and enable Assign group policies by device type. Click Add group policy for a device type for each Apple device type (iPhone, iPad, iPod, and Mac OS X) and assign the Apple device group policy you created. Click save and your optimization is complete.

Vocera Badges

Vocera badges communicate to a Vocera server, and the server contains a mapping of AP MAC addresses to building areas. The server then sends an alert to security personnel for following up to that advertised location. Location accuracy requires a higher density of access points. In a high density deployment, you may need to reduce the transmit power of each AP manually to as low as 5 dB on all supported radios. Vocera provides additional documentation on deploying WLAN best practices to support Vocera badges. For more information download their document on Vocera WLAN Requirements and Best Practice

WiFi Calling

Mobile network operators (MNOs) now allow their customers to place phone calls over Wi-Fi to save roaming costs and leverage WiFi coverage in buildings with poor cellular coverage. WiFi calling is expected to be supported by majority of mobile devices and MSPs by the end of 2015. Apple maintains a list of carriers that have wifi calling ready and devices that support it. 

An Enterprise WiFi infrastructure handles more than just carrier voice traffic, and this limited spectrum is shared by other applications and services like Video streaming & Web Conferencing. The requirements for voice in terms of latency and jitter warrants a network with proper end-to-end QoS design & Voice optimizations that would optimize delivery of WiFi calling packets in the presence of other applications.

Hotspot 2.0

Hotspot 2.0 also known as Passpoint is a service provider feature that assists with carrier offloading. Part of the 802.11u amendment to the 802.11 standard additional information is included in Hotspot 2.0 configured SSIDs that Hotspot 2.0 client devices can analyze use to determine if it is able to join the network automatically. 

Managed Service Providers (MSPs) can now take enable of Hotspot 2.0 options on the Cisco Meraki MR access points. Meraki allows MSPs to customize the Hotspot 2.0 SSID advertisements to allow their subscribers to easy roam between networks.  Hotspot 2.0 options are only available to qualified Managed Service Providers. Please contact Cisco Meraki Support to check eligibility.