Wireless Network Deployment

1
Wireless Network Deployment

• Planning Through Implementation

2
Assumptions

• Business criteria (organizational mission, user
  needs, ROI . . .)
• Enterprise level (or scalable to it)
• Adding infrastructure wireless to an existing
  wired LAN
• Compromises will be necessary

3
Rationale

• How would a WLAN aid your mission?
• Increase productivity?
• Improve customer service?
• Lower costs?
• Why do you want/need wireless?
• Just to avoid running wires?
• For portability?
• For mobility (e.g., roaming)?

4
Rationale (cont.)

• Who would use the WLAN?
• Employees?
• Customers/clients?
• The public?

5
User Requirements

• Throughput
• Coverage area
• Portability
• Mobility/roaming
• Number of users
• QoS
• Applications run
• User privacy/security needs

6
Mobility Roaming Options

• ESS on the same IP subnet
• ESS on the same layer 2 net
• Flat logical backbone
• VLANs can provide a dispersed physical backbone
• IAPP (possibly proprietary)
• Single-vendor options
• ESS on multiple IP subnets
• One SSID w/o roaming or multiple SSIDs
• Mobile IP (standardized but still not widely
  available)
• Another option dedicated wired/wireless switches
  with Proxy Mobile IP, etc.

7
Address Management

• APs can use static or DHCP addresses
• Clients should probably use DHCP
• Ideally from a central server (not by APs)
• Everything can be in private ranges

8
Initial Planning

• Physical topology
• Logical topology
• Network security
• Site environment
• Standards
• Access point HW/SW options
• Client hardware HW/SW options
• Network management HW/SW

9
Feasibility Checkpoint

• Technical feasibility
• Economic feasibility
• Organizational feasibility
• Schedule feasibility
• Project management plan

10
Choosing Standards

• 802.11b 11 Mbps nominal, 2.4 GHz, very common
  well supported
• 802.11a 54 Mbps nominal, 5 GHz, possible niche
  role
• 802.11g 54 Mbps nominal, 2.4 GHz, likely
  successor to b (some issues with simultaneous b
  and g client connections)
• Next generation 802.11n (possible 100 Mbps) etc.

11
Choosing APs

• Standards compliance
• Manageability (individually and as a group)
• Scalability
• Securability
• Configurability
• Range, coverage patterns, antennas, power output,
  channel usage . . . dozens of parameters . . .
• Upgradeability
• Price

12
Access Point Management Interfaces

• Vendor-supplied management SW (via serial
  connection, USB, network)
• CLI (including via Telnet)
• HTTP/Web (imbedded web server)
• SNMP (possibly with custom software and custom
  MIBs)

13
Access Point Security

• Signal shaping
• MAC authentication
• WEP Wired Equivalent Privacy
• Specialized switches appliances
• Next-generation
• 802.11i Robust Security Network (RSN) and
  Transitional Security Network (TSN)
• Wi-Fi Protected Access (WPA)
• You can (should!) layer on IPSec, SSH, etc.
• Dont forget physical security for the APs
  themselves

14
Site Survey Planning

• Obtain blueprints
• Note type of construction
• Note wired power network availability
• Identify interference sources
• Microwave ovens
• Cordless phones
• Bluetooth
• Wireless cameras

15
Choosing Client HW/SW

• Homogeneous HW you own
• Heterogeneous HW from customers, etc.
• Built-in versus PC-card, etc.
• Standards compliance compatibility
• Power levels, range, antennas . . .
• Security features supported
• Price

16
Testing

• Deploy a test access point on a test network
• Map signal strength patterns
• Connect with clients
• Test throughput
• Test usage of typical applications
• Test security

17
Final Configuration Installation

• Access point configuration
• Naming convention
• Channel usage
• Beaconing
• Security settings
• Client configuration
• To match access points

18
Documentation

• Network maps
• Physical, with AP locations, etc.
• Logical, with subnets, address ranges, etc.
• Configuration databases for access points
• Password management
• User guides

19
Ongoing Management

• Monitor usage
• Conduct periodic security audits
• Troubleshoot problems
• Integrate with existing help desk/trouble ticket
  system, if any
• Plan for upgrades and capacity increases as needed