New WLAN management solution

Industry's best Wi-Fi management solution

Cloud powered, supports leading enterprise access points

 

Looks Promising ! Nira Wireless is taking big steps in the field WLAN management.

Cloud powered management of your Cisco, Aruba or Motorola Access Points.This way they are not tied to one vendor while moving from 802.11n, to 802.11ac WAV1 and WAV2 access points. Also, unlike vendor provided solutions, Nira's product are not partial to any particular vendors APs.

Looking forward for hands on with the tool and will update the experience.

http://www.nirawireless.com/features

Control Plane & Data Plane

The control plane is the part of a network that carries signaling traffic and is responsible for routing.

The data plane (sometimes known as the user plane, forwarding plane, carrier plane or bearer plane) is the part of a network that carries user traffic.

 Let's consider the example of  the management of public transportation of a city.

Before we send bus drivers out, we need to have a plan.

Control Plane = Learning what we will do

Our planning stage, which includes learning  which paths the buses will take, is similar to the control plane in the network.   We haven't picked up people yet, nor have we dropped them off, but we do know the paths and stops due to our plan.  The control plane is primarily about the learning of routes.

In a routed network, this planning and learning can be done through static routes, where we train the router about remote networks, and how to get there.   We also can use dynamic routing protocols, like RIP, OSPF and EIGRP to allow the routers to train each other regarding how to reach remote networks.   This is all the control plane.

Data Plane = Actualy moving the packets based on what we learned.

Now, after the routers know how to route for remote networks, along comes a customers packet and BAM! this is were the data plane begins.   The data plane is the actual movement of the customers data packets over the transit path.   (We learned the path to use in the control plane stage earlier).

 

Fun Programming: For Network Engineers

Sometimes its a tedious task to manually configure CLI's on the network devices.
Imagine how much time it will take to configure say near to 100 ACL or VLAN and then configuring each of them.Well the question is not about how to improve your typing skills indeed its about leveraging programming/coding skills for these simpler task to save time and be more efficient.I realize most networking folks aren't going to run out and start doing Tcl programming.

As its almost everywhere "Programming: An Essential Skill For Network Engineers" http://ubm.io/1pKNb9f

WHY not to start with some basic scripting to make life easier :

Cisco has embedded TCL in CISCO IOS.The Tcl interpreter is invoked by typing "tclsh" at the enable EXEC mode prompt. The Tcl shell attempts to interpret a command as a Tcl command. If that fails, it then tries to interpret the command as a Cisco CLI command.Your Tcl program can issue EXEC or CONFIG mode commands. This allows you to write Tcl programs to build menus or walk junior staff through configuration tasks.

Command	Purpose
ios_config "command" "sub-command" Example: ios_config "interface Ethernet 0" "description this is a demo"	Run a Cisco IOS configuration command (sub-mode commands must be quoted on the same line as the main configuration command)

Example:

Configuring 50 VLAN.

1. tclsh
2. for {set I 1} {$I < 51} {incr I} {
ios_config "vlan $I" "exit"
}
3. exit
4. show vlan

Yipee , its done .

Shannon's Law

Shannon's Law, formulated by Claude Shannon , a mathematician who helped build the foundations for the modern computer, is a statement in information theory that expresses the maximum possible data speed that can be obtained in a data channel.

The law, formulated by Claude Shannon of Bell Telephone Labs, says that the data capacity, in bits per second, is a function of the bandwidth, the signal strength, and the noise in the channel.

 c = b log2 (1 + s)

No practical communications system has yet been devised that can operate at close to the theoretical speed limit defined by Shannon's law.

But DIDO allows each user to communicate, in theory, up to the full Shannon limit of the channel.

Distributed-Input-Distributed-Output (DIDO) wireless technology is a breakthrough approach that allows each wireless user to use the full data rate1  of shared spectrum simultaneously with all other users, by eliminating interference between users sharing the same spectrum.

WiFi Site Survey

 

Many network managers will simply install extra WiFi APs as a quick fix to increase the wireless coverage capability. However, that often does little .

There are three different types of site surveys widely used in the industry: passive site survey, active site survey, and predictive site survey.

A passive site survey tool listens to existing access points and, outside your managed infrastructure, for signal strength, interference, and AP coverage. Passive site surveys, in which surveyed WiFi adapters don't need to associate to the AP or SSID, give a good overall picture of the RF characteristics of existing wireless networks.

During an active site survey, the survey WiFi adapter is associated to the AP(s) and exchanges packets. This allows gathering of very detailed information. Actual network traffic, throughput packet loss, and physical (PHY) rates can be captured. Active surveys are commonly used for new WLAN deployments.

A predictive site survey is performed without any type of field measurements. It uses RF planning software tools that can predict wireless coverage of the APs. To perform this site survey, a floor-plan drawing (AutoCAD, JPEG, PDF) is a must-have. Predictive site surveys are used when the site or building is not yet built and are helpful for budgeting purposes.

The goal of all of these wireless site surveys is to provide detailed information that addresses the site’s radio frequency coverage. Before implementing or attempting to optimize a WLAN, you’ll want to understand all the possible areas of interference, AP placements, power considerations, and wiring requirements that are needed. A wireless site survey can provide all of this information and more, so you have the tools you need to design, implement, and optimize your wireless network.

Which is faster 40Mhz vs 2x20Mhz ?

Well the question is whether should we use one AP working on 40 Mhz channel width or should we have 2 AP with each channel width configured to 20 Mhz.

The answer is somewhat clear that 2 AP will provide good redundancy and better management.

Points to Consider:

1. CPU Utilization will be less and get shared on 2 AP , better than loading single AP with more clients which will result to High CPU Utilization and degrade AP performance.

2. Contention mechanism would allow better chances to the clients.

3. The more degrees for freedom offered in network solution, the more resilience and quality of user experience is likely achieved.

VSS : Virtual Switching System

Combing/integrating two switches virtually and make them work as one , a redundancy feature called Virtual switching system (VSS).




The main reason for VSS is something that is typically addressed when there are redundant routing platforms on a network. A VSS is network system virtualization technology that pools multiple Cisco switches into one virtual switch, increasing operational efficiency, boosting nonstop communications, and scaling system bandwidth capacity to 1.4 Tbps.

VSS actually removes the need for a next-hop redundancy protocol like HSRP or VRRP. These first-hop redundancy protocols are usually heavily tied to a fast-converging routing protocol like EIGRP, and still require that each device maintain it’s own control plane. Often, two switches are configured, and one responds to ARP requests while the other does not. This is an active/passive relationship. VSS takes this a step further and actually merges the two switches into one virtual “mega-switch”, rather than wasting a perfectly good switch. There’s still a master/slave relationship, but rather than placing one switch in standby while the other is active, this determines which switch maintains control over the other. The function of the supervisor module, as well as the configuration of both switches, becomes the responsibility of the primary switch.

VSS utilizes the port channel between the switches to merge them together into one massive switch. As a result, redundant connections from the Access layer to the Core no longer need to be blocked because since they’re virtually both connected to the same switch, they can be configured in a port-channel, as shown by the diagram to the right. http://www.cisco.com/c/en/us/products/collateral/switches/catalyst-6500-virtual-switching-system-1440/prod_qas0900aecd806ed74b.html

IoT : Internet of Things

The Internet of Things (IoT) is the network of physical objects accessed through the Internet, as defined by technology analysts and visionaries. These objects contain embedded technology to interact with internal states or the external environment. In other words, when objects can sense and communicate, it changes how and where decisions are made, and who makes them.

"or"

The Internet of Things (IoT) is a scenario in which objects, animals or people are provided with unique identifiers and the ability to automatically transfer data over a network without requiring human-to-human or human-to-computer interaction. IoT has evolved from the convergence of wireless technologies, micro-electromechanical systems (MEMS) and the Internet.

A thing, in the Internet of Things, can be a person with a heart monitor implant, a farm animal with a biochip transponder, an automobile that has built-in sensors to alert the driver when tire pressure is low -- or any other natural or man-made object that can be assigned an IP address and provided with the ability to transfer data over a network. So far, the Internet of Things has been most closely associated with machine-to-machine (M2M) communication in manufacturing and power, oil and gas utilities. Products built with M2M communication capabilities are often referred to as being smart.

IPv6’s huge increase in address space is an important factor in the development of the Internet of Things. According to Steve Leibson, who identifies himself as “occasional docent at the Computer History Museum,” the address space expansion means that we could “assign an IPV6 address to every atom on the surface of the earth, and still have enough addresses left to do another 100+ earths.” In other words, humans could easily assign an IP address to every "thing" on the planet. An increase in the number of smart nodes, as well as the amount of upstream data the nodes generate, is expected to raise new concerns about data privacy, data sovereignty and security.
Although the concept wasn't named until 1999, the Internet of Things has been in development for decades. The first Internet appliance, for example, was a Coke machine at Carnegie Melon University in the early 1980s. The programmers could connect to the machine over the Internet, check the status of the machine and determine whether or not there would be a cold drink awaiting them, should they decide to make the trip down to the machine.http://whatis.techtarget.com/definition/Internet-of-Things

3 Layer Hierarchical Internetworking Model

The Hierarchical internetworking model, or three-layer model, is a network design model first proposed by Cisco. The three-layer model divides enterprise networks into three layers: core, distribution, and access layer. Each layer provides different services to end-stations and servers.

Each layer in the three-tier hierarchical model has a unique role to perform: 

•Access Layer—The primary function of an access-layer is to provide network access to the end user. This layer often performs OSI Layer-2 bridge function that interconnects logical Layer-2 broadcast domains and provides isolation to groups of users, applications, and other endpoints. The access-layer interconnects to the distribution layer.

•Distribution Layer—Multi-purpose system that interfaces between access layer and core layer. Some of the key function for a distribution layer include the following:

–Aggregate and terminate Layer-2 broadcast domains

–Provide intelligent switching, routing, and network access policy function to access the rest of the network.

–Redundant distribution layer switches provides high availability to the end-user and equal-cost paths to the core. It can provide differentiated services to various class-of-service applications at the edge of network.

•Core Layer—The core-layer provides high-speed, scalable, reliable and low-latency connectivity. The core layer aggregates several distribution switches that may be in different buildings. Backbone core routers are a central hub-point that provides transit function to access the internal and external network.

 http://www.cisco.com/c/en/us/td/docs/solutions/Enterprise/Education/SchoolsSRA_DG/SchoolsSRA-DG/SchoolsSRA_chap3.html

DHCP : Dynamic Host Configuration Protocol

Well , DHCP is not a confusing topic to discuss on. But people sometimes get confused when asked whether DHCP OFFER or DHCP ACK  is a unicast or broadcast packet.

Lets understand the DHCP DORA process.

D : DHCP Discover
O : DHCP Offer
R : DHCP Request
A : DHCP Acknowledgement

DHCP Discover :  is broadcast packet
 DHCP Offer :  can be a broadcast or unicast packet (depends upon flag set in client  DHCP Discover                                  broadcast field)
DHCP Request :  is a broadcast packet
 DHCP Acknowledgement :  can be a broadcast or unicast packet

Reason why DHCP Offer and Ack can be either unicast or broadcast packet ?

A client that cannot receive unicast IP datagrams until its protocol software has been configured with an IP address SHOULD set the BROADCAST bit in the 'flags' field to 1 in any DHCPDISCOVER or DHCPREQUEST messages that client sends. The BROADCAST bit will provide a hint to the DHCP server and BOOTP relay agent to broadcast any messages to the client on the client's subnet. A client that can receive unicast IP datagrams before its protocol software has been configured SHOULD clear the BROADCAST bit to 0.

PBR or VRF

(For the basics on PBR and VRF , please refer the other posts in the same blog.)

Most of the times , it seems PBR will work and there is no need to create VRF instances on a router.Well, what VRF gives you is completely de-coupled routing tables between interfaces. So for one ingress interface into the router, you use routing table A, and for another ingress interface, routing table B.

All interfaces belong to *one* VRF only, so if you want to share an interface between traffic of "sort A" and "sort B", things with VRFs get tricky. You can do this with VRF select ("match an access-list, and depending on the result, go to VRF routing table A or B or C..."), but that's a lot of configuration stuff if all you need to do is sort incoming traffic on one interface.

PBR will give you a lever to sort incoming traffic according to some rules you define in a route-map, bypassing(!) normal routing tables. PBR is more powerful than VRFs, if the point is "sorting traffic coming in on *one* interface", but if you need to scale this to dozens of routers, and hundreds of interfaces, PBR will just be too complex to get right.

VRF : Virtual Routing & Forwarding

If you are keen and interested in Virtualization then VRF (Virtual Routing and Forwarding) is the technology you should definately have a look.

VRF , also known as VPN routing and forwarding.

Virtual routing and forwarding (VRF) is a technology included in IP (Internet Protocol) network routers that allows multiple instances of a routing table to exist in a router and work simultaneously. This increases functionality by allowing network paths to be segmented without using multiple devices. Because traffic is automatically segregated, VRF also increases network security and can eliminate the need for encryption and authentication. Internet service providers (ISPs) often take advantage of VRF to create separate virtual private networks (VPNs) for customers.

Each VRF acts as a separate router. Each router will have its own interfaces and its own routing table. The routes in the routing table of one VRF are not visible in any other VRF neither in the global routing table.

VRFs are to Layer 3 what VLANs are to layer 2. They provide a fully isolated network path. Nothing can map from one to the other without the administrator creating a link. VRFs are most common in service providers MPLS networks to isolate different customers. They also can have a roll in corporate networks as well in the form of VRF-lite. Let’s look at a sample deployment scenario: You have two internet connections, one for guest users and one for corporate users. Each is required to be completely isolated from the other. You have VLANs to separate these two classes of users within your network as well. Your network has grown to the point of needing routing inside the corporate network. Enter VRFs. Let’s look at the design in the image below:

VRFs split a routed network while VLANs split a switched network

The Blue lines indicate our corporate network while Red is the guest network. Each has its own path to the internet despite the fact common hardware is in use.

PBR : Policy Based Routing

Policy-Based Routing (PBR) allows you to use ACLs and route maps to selectively modify and route IP packets in hardware.

(PBR) allows you to use ACLs and route maps to selectively modify and route IP packets in hardware. Basically, the ACLs classify the traffic and route maps that match on the ACLs set routing attributes for the traffic.

A PBR policy specifies the next hop for traffic that matches the policy:

·         For standard ACLs with PBR, you can route IP packets based on their source IP address.

·         For extended ACLs with PBR, you can route IP packets based on all of the matching criteria in the extended ACL.

The problem that many network engineers find with typical routing systems and protocols is that they are based on routing the traffic based on the destination of the traffic. Now under normal situations this is fine, but when the traffic on your network requires a more hands on solution policy based routing takes over.

Destination based routing systems make it quite hard to change the routing behavior of specific traffic. With PBR, a network engineer has the ability to dictate the routing behavior based on a number of different criteria other than destination network, including source or destination network, source or destination address, source or destination port, protocol, packet size, and packet classification among others.

PBR also has the ability to implement QoS by classifying and marking traffic at the network edge and then using PBR throughout the network to route marked traffic along a specific path.

So why would you do this? Well consider a company that has two links between locations, one a high bandwidth, low delay expensive link and the other a low bandwidth, higher delay lower expense link.

Now using traditional routing protocols the higher bandwidth link would get most if not all of the traffic sent across it based on the metric savings obtained by the bandwidth and/or delay (using EIGRP or OSPF) characteristics of the link. PBR would give you the ability to route higher priority traffic over the high bandwidth/low delay link while sending all other traffic over the low bandwidth/high delay link.

This way the traffic which requires the characteristics of the high bandwidth/low delay link would be possible without sending all traffic over the link.

http://blog.pluralsight.com/pbr-policy-based-routing

 http://www.cisco.com/c/en/us/td/docs/ios/12_2/qos/configuration/guide/fqos_c/qcfpbr.html

Types of ARP

Most of us are aware of ARP (address resolution protocol) and its functionality.

1.ARP is a layer 3 protocol.
2.Help to find the mac address using ip address.

Types of ARP

RARP
IARP
Proxy-ARP
Gratuitous ARP

Proxy ARP

Host A wants to send data to Host B which is not on that network, Host A sends an ARP to get a MAC address for host B. Router (gateway) replies to Host A with its own MAC address stating itself as destination (something like a proxy roll call when you respond as present to a roll call of your friend), hence when the data is sent to the destination by Host A it would be sending to the gateway (as destination MAC is given as Gateway's MAC) which would in-turn send to host B. This is called proxy arp

Gratuitous ARP

Gratuitous ARP could mean both gratuitous ARP request or gratuitous ARP reply. Gratuitous in this case means a request/reply that is not normally needed according to the ARP specification (RFC 826) but could be used in some cases. A gratuitous ARP request is anAddressResolutionProtocol request packet where the source and destination IP are both set to the IP of the machine issuing the packet and the destination MAC is the broadcast address ff:ff:ff:ff:ff:ff. Ordinarily, no reply packet will occur. A gratuitous ARP reply is a reply to which no request has been made.

Gratuitous ARPs are useful for four reasons:

• They can help detect IP conflicts. When a machine receives an ARP request containing a source IP that matches its own, then it knows there is an IP conflict.
• They assist in the updating of other machines' ARP tables. Clustering solutions utilize this when they move an IP from one NIC to another, or from one machine to another. Other machines maintain an ARP table that contains the MAC associated with an IP. When the cluster needs to move the IP to a different NIC, be it on the same machine or a different one, it reconfigures the NICs appropriately then broadcasts a gratuitous ARP reply to inform the neighboring machines about the change in MAC for the IP. Machines receiving the ARP packet then update their ARP tables with the new MAC.
• They inform switches of the MAC address of the machine on a given switch port, so that the switch knows that it should transmit packets sent to that MAC address on that switch port.
• Every time an IP interface or link goes up, the driver for that interface will typically send a gratuitous ARP to preload the ARP tables of all other local hosts. Thus, a gratuitous ARP will tell us that that host just has had a link up event, such as a link bounce, a machine just being rebooted or the user/sysadmin on that host just configuring the interface up. If we see multiple gratuitous ARPs from the same host frequently, it can be an indication of bad Ethernet hardware/cabling resulting in frequent link bounces.

Layer 4 TCP Flags

The TCP (Transmission Control Protocol) is layer 4 protocol of OSI stack.
rather than going on to the basics of  TCP like understanding its a connection oriented protocol and else ; Lets discuss the 5 FLAGS :

1.SYN : Initiates a connection
2.ACK : Acknowledges received data
3.URG : Discussed Below
4.PSH : Discussed Below
5.RST :Aborts a connection in response to an error
6.FIN :Closes a connection

"PSH FLAG"

To understand the function of the PSH flag, we first need to understand how TCP buffers data. TCP operates at layer four of the OSI model; it presents to upper layers a simple socket which can be read from and written to, masking the complexities of packet-based communications. To allow applications to read from and write to this socket at any time, buffers are implemented on both sides of a TCP connection in both directions.

Buffers allow for more efficient transfer of data when sending more than one maximum segment size (MSS) worth of data (for example, transferring a large file). However, large buffers do more harm than good when dealing with real-time applications which require that data be transmitted as quickly as possible. Consider what would happen to a Telnet session, for instance, if TCP waited until there was enough data to fill a packet before it would send one: You would have to type over a thousand characters before the first packet would make it to the remote device. Not very useful.

This is where the PSH flag comes in. The socket that TCP makes available at the session level can be written to by the application with the option of "pushing" data out immediately, rather than waiting for additional data to enter the buffer. When this happens, the PSH flag in the outgoing TCP packet is set to 1 (on). Upon receiving a packet with the PSH flag set, the other side of the connection knows to immediately forward the segment up to the application. To summarize, TCP's push capability accomplishes two things:

• The sending application informs TCP that data should be sent immediately.
• The PSH flag in the TCP header informs the receiving host that the data should be pushed up to the receiving application immediately

"URG FLAG"

The URG flag is used to inform a receiving station that certain data within a segment is urgent and should be prioritized. If the URG flag is set, the receiving station evaluates the urgent pointer, a 16-bit field in the TCP header. This pointer indicates how much of the data in the segment, counting from the first byte, is urgent.

Basics of WiFi Power Saving Mechanisms

·         Power savings can be achieved by the STA when it indicates to the AP that it is entering power save mode and shutdown its receive path.

·         The AP stores frames destined to an STA in power save mode and sends them to the STA when requested to do so.

·         During association, an STA uses the Listen Interval parameter to indicate to the AP how many beacon intervals it shall sleep before it retrieves the queued frames from the AP( The AP shall not drop any queued frames until the STA's Listen Interval elapses).

Legacy Power Save Polling

·         An STA enters power-save mode by sending a Null frame to the AP with the Power Management bit set.

·         From then on, the AP stores all packets destined to the STA in a per-STA queue and sets the TIM field in the beacon frame to indicate that packets destined for the STA have been queued at the AP.

·         An STA wakes up from sleep every Listen Interval to receive the beacon frame and when it detects that the TIM field for it has been set, it sends a PS-Poll frame to the AP.

·         In response, the AP sends the first queued frame to the STA. The STA receives the queued data frame and if the More Data field in this frame is set, it sends another PS-Poll frame to the AP.

·         The STA continues to send PS-Poll frames to receive all the queued frames and when none are left, it goes back to sleep until the next Listen Interval.

·         In legacy power-save mode, the frames are exchanged with DIFS separation so that other STAs can take over the medium.http://www.wifi-insider.com/wlan/psd.htm

What is my ip address ???

If you are keen and interested to know :

                   1. What is your system ip address?
                   2. Speed of the internet connection ?
                   3. How to change your system ip address ?
                   4. How to hide the system ip address ?

Logon to : http://whatismyipaddress.com/

from my experience i can tell it is one of the best website which gives you accurate details on whatever you want to know about your system ip , location , services etc ....

http://whatismyipaddress.com/

WLAN analyzers available in market

Too often, I find people using inferior tools for getting a general WLAN overview.Well there are a number of freely avail'able tools which anybody can download and use it to analyze/capture the wifi packets.But the question is  : " Does these tools really work ?".

The answer is very clear , "YES" these freely available wifi analyzers will work for most of the basic work to be done.But if you are looking for a full fledged tool which will monitor and capture each and every packet on your wifi setup then there is a strong reason to buy the best wifi analyzers available in the market.

Below given is the list of both freely and licensed versions of WLAN analyzers.

Freely available :

1.Microsoft Network Monitor

2.Wireshark

(Please use  the laptop with the best wifi card while using Microsoft Network Monitor and for Wireshark it is recommended to buy Airpcap USB adaptor for the best results)

Best available WLAN analyzers :

1.Wildpackets Omnipeek
2.Fluke Networks Air Magnet Wifi analyzer

(Air Magnet while compared to Omnipeek will give more graphical results but if the need is to perform detailed packet analysis then choose Omnipeek.
Buy the Linksys WUSB6300 USB adaptor or Cisco AE6000 while using omnipeek for 802.11ac packet analysis.)


http://www.virtualization.co.kr/reference/WP_Miller_WLANAnalyzer.pdf

IEEE 802.11ac mandatory Features

Dont get confused with a list of 802.11ac features.Check this below given table for the mandatory features of 11ac.

IEEE 802.11ac MANDATORY FEATURES

Top 5 Tips for Deploying 802.11ac

                                   

1. 1. Design for capacity
   With an average corporate mobile device/user ratio approaching 3 (laptop, tablet, and/or smartphone), capacity has become a problem for wireless networks. Higher data rates introduced in 802.11ac can increase capacity and performance for clients, but only if the WLAN is carefully planned and deployed. Taking account of key performance factors such as increased channel width (80 and 160 MHz wide channels) and higher MCS is crucial to improving capacity.
2.  
3. 2. Ensure backwards compatibility with 802.11 a/n devices
   Migration to 802.11ac will not happen overnight. There will always be a need to ensure 802.11ac deployment is backwards compatibile with legacy devices. Though 802.11ac is backwards compatible with 802.11n and 802.11a, performance for 802.11ac clients may be adversely impacted because of slower transmission rates by 802.11a/n clients. Identifying areas where legacy devices need to be supported and accordingly planning 802.11ac deployment will maximize performance for all clients.
4.  
5. 3. Survey your site prior to deployment
   It’ll take a proper survey to assess the coverage of your current network, which you’ll need to do to determine if more APs are needed. Look for obstacles in the current environment when planning your update. Be sure to measure actual throughput of your existing network and assess if it meets your requirements. Is there a need to support bandwidth heavy applications in certain areas? Or is wireless access needed primarily for web browsing? Tool like Fluke Networks’ AirMagnet 8.6 can help speed this process and provide insight into these issues.
6.  
7. 4. Plan your network carefully, use survey results to limit rollout issues
   Based on your user base and pre-deployment survey, carefully determine the number of APs needed and their placement. Also determine areas wherewider channels are needed to maximize throughput, and how they will be assigned to each AP to minimize co-channel interference and maximize performance.
8.  
9. 5. Validate after deployment
   Determine how well your network is performing after deployment. Are there areas affected by poor coverage or channel interference? What about actual throughput? Determine 802.11ac network readiness based on your requirements. As always, the most important validation is a successful end-user experience.
10.  

Real world performance for end users has to be a major consideration when designing a 802.11ac deployment plan. Put simply, end users care very little about how many bars they see on their Wi-Fi connection icon; they want the network to “feel” fast, for web pages to load quickly and video to stream smoothly.

There are tools that allow network planners to see a graphical representation of their physical network environment and test various configurations of APs and network settings to see the likely impact on end user performance before any actual hardware is deployed. Up-front planning and scenario testing could be the difference between an 802.11ac rollout that goes smoothly and satisfies end users and one that requires a costly and time consuming post-deployment reconfiguration.

Source: http://www.airwisecommunity.com/blog/#plckblogpage=BlogPost&plckpostid=Blog:408541b3-77cb-438d-8627-b3cf15d368eePost:f701dc10-168b-4512-8ac0-51f6edc6754d