webinar netgear - linee guida per il disegno di una rete wireless a elevate prestazioni
TRANSCRIPT
Linee guida per il disegno di una rete
Wireless a elevate prestazioni
Formazione Online
Andrea Rossi – System Engineer
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Product Portfolio
Storage
Security Switching
Wireless
Business
Know Your Deployments
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Coverage Limited Capacity Limited
Considerations
+ How many Wireless Devices will want connectivity to the WLAN?
+ Where will these devices be and what area does it need to cover?
+ What applications would you like to use over the WLAN?
+ Would guest access or multiple groups be a requirement?
+ How is the current wired network constructed? 100mb? Gigabit? Fibre / Copper?
+ What levels of Security are needed?
+ What about future expansion? Other types of devices?
+ Would the system be used for VoIP calls?
+ Is there a requirement for external coverage?
What is considered High Density?
+ Large number of people in a small confined area
+ High demand of application access on Wireless
+ General Rule of Thumb:
•More than 20 active users in the proximity of coverage of single AP (500 – 1000 ft2)
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How much throughput your AP support?
300 Mbps * 2 = 600 Mbps (dual band 2x2 AP)
30 users
600 Mbps / 30 = 20 Mbps
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We support 20 Mbps per user !!
Common Sizing Mistake
Better Rule of Thumb Design of High Density
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For 25 Active Clients: Avg of 2 – 3 Mbps / client
Start Impact After
600 Mbps Packet and protocol overhead (-50%) 300 Mbps
300 Mbps Slow or ‘far-away’ clients (-50%)!! 1 Mbps client takes 100x more airtime to transmit 1 frame vs. a
100 Mbps client (.11a/b/g clients or clients at the edge of cell)
150 Mbps
150 Mbps Uneven distribution of 2.4/5 clients (-50%) 75 Mbps
75 Mbps Control traffic (-25%)Multicast, control, probe, etc. generally at 1 Mbps rate
50 Mbps
50 Mbps OthersInherent co-channel and adjacent channel interference, bad
behavior clients, network re-transmissions
What is the typical bandwidth needed per application?
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Video Throughput
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Typical rule of thumb: 1 to 3 Mbps
Parameters for Capacity Based Networks
+ # of users in a specific area covered by single AP
+ # of Wi-Fi devices per person
+ % of users that are expected to be active
+ Types of applications and throughputs needed
+ Mix of applications
+ Type of clients in the network (2.4 vs. 5 GHz)
+ Legacy vs. .11n clients
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Parameters for Coverage Based Networks
+ Floor plan
+ Types of constructions and obstructions• concrete, brick, drywalls, elevator shafts
+ Types of deployment• Offices, cubicle, warehouse, single room motels/hotels
+ Height of floor• 10 feet/3 meter (offices), 20 feet/6 meter (warehouse), 30 feet/9 meter (gym)
+ # of floors
+ Exclusion area
+ High density / Low density separations
+ Important coverage areas• CEO office, guests/publicity areas
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High Density Recommendation (1)(start with AirPlanner and Identify High Density areas)
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High Density Area
High Density Recommendation (2)(Dual Band Concurrent Access Points)
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YES
WNDAP360
WNDAP350
WNDAP660
NO
WNAP210
WN370
WNAP320
WNDAP620
Enable both 2.4 + 5 GHz Radios
High Density Recommendation (3)(Design overlap with 2-3 AP connectivity)
14HD Area with 3 AP Coverage
High Density Recommendation (4)Load Balancing to meet excess load
Set the max client for each radio at 25
Set the minimum RSSI threshold to connect at 40 (-73 dBm)
High Density Recommendation (5)turn down power, not up
+ Often mistake is turn up AP power, but that will cause co-channel and adjacent channel interference
+ Turning 2.4 GHz output power to ½ or ¼ and 5 GHz output power to ½ and add more AP is better solution
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High Density Recommendation (6)Upgrade wired network
L3 L2 AP
1G links1G or 10GMultiple 10 or
100 Mbps
High Density Design Recommendations
+ Start with AirMagnet planner and identify locations of High Density
+ Always spec’d AP with dual band concurrent radios• YES: WNDAP350/360/660
• AVOID: WNAP210/320/620/WN370
+ Always enable both radios
+ Design Wi-Fi where all clients can reach 2-3 AP’s
+ Load balancing to spread out traffic to less loaded AP’s
+ Upgrade wired network to support higher throughput AP’s
+ Explore to use bonded 40 MHz channels in 5 GHz where appropriate
+ Actual stress test prior to live deployment
Why Basic Survey?
+ Gain Visibility of site and gain clearer idea of requirement.
+ Understand the environment and how RF performs / check interference.
+ Understand the Network background, and provide opportunities to supply other technologies (Security/ Switching / POE / Storage).
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Types of Wireless Site Surveys
Three main types of surveys
Passive Active Predictive
Listen for
Signal strength
Noise Level
Not associated
Associate to AP
Round trip time
Throughput
Packet loss
Simulated
Modeling
RF attenuation
Wall construct
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&
Onsite evaluation
Plan your visit…
Tools 1st 30 minutes Timing
PC
Camera/phone
WiSpy
AirMagnet
InSSIDer
RF Spectrum
Floor map
Visual check
Requirement synch
Test locations
PoE !!
Single floor (hours)
Multi floors (days)
Multi bldgs (week)
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&
Conduct TestsActive Survey
AP Location
Associate to AP
Walk around Record
Key Parameters
Record boundaries
New Location
Passive Survey
Interferers, Other AP’s, Channels
Throughput (Mbps)
Round trip time (msec)
Packet loss
Signal strength (dBm)
Signal to noise (dBm)
Background noise (dBm)
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PROJECT ANALISYS
PROJECT DEFINITION
EXPANSION
Where NETGEAR can help
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Product Portfolio
Storage
Security Switching
Wireless
Business
WNAP210
WNAP320
WNDAP350
WNDAP360
WN370
a/b/g/n(2x)
Multi-BSSID
Controller
Managed
Performance
WNDAP620
WNDAP660
450 Mbps
3x3 802.11n
Advanced Security
Controller
Managed
Premium
WN203
WN604
WAC120
Simple installation
Basic security
Standalone
SOHO
Access Point Diversity
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Explore Controller
Compatibility
WND930
300 Mbps
2x2 802.11n
Advanced Security
Controller
Managed
Outdoor
Why a Wireless Controller?
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Helps speed up deployment:
• Easy User Interface -hiding sophisticated algorithms
• Integrated planning tools: Predicted coverage per building / floor
Helps stay connected:
• Seamless L2/L3 fast roaming
• Automatic load balancing and RF planning, incl. advanced QoS / Rate limiting
Helps enforce comprehensive
security:
• RADIUS, Active Directory authentication
• VLANs compliance, internal / external AAA server
• Captive portal and Guest access management
Wireless Controller Solution Scalability
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Up to 2500 devices Up to 6000 devices 15000+ devices
Wireless Controller / Management Solution
ProSAFE Wireless
Controller• Secure, enterprise class control
• Scale from 20 to 150 AP’s
• Stack 3 Controllers to support upwards of 3000 devices
• Full mobility / roaming support
• Guest Captive Portal
• Stack for redundancy / resiliency
• 10 AP incremental license
WC7520
Advanced, performance based wireless management
• Secure, enterprise class control
• Scale from 2 - 50 APs per
controller
• Stack 3 Controllers to support
upwards of 6000 devices
• Stack for redundancy / resiliency
• 802.11ac ready
• Premium 11n AP support
• 10 AP incremental license
ProSAFE WC7600
Product Detail
Advanced, performance and high density based wireless management
• Secure, enterprise class control
• Scale from 2 - 300 APs per
controller
• Stack 3 Controllers to support
upwards of 18000 devices
• Stack for redundancy / resiliency
• 802.11ac ready
• Premium 11n AP support
ProSAFE WC9500