Information Systems:Wireless Infrastructure (WLAN)

Overview

This article documents the current wireless infrastructure. A complete overhaul of the wireless was conducted in July 2017; the old article is now located here.

The WiNG platform by Extreme Networks is used for wireless at uniPHARM.

Configuration

Access Points

• The model of AP is the Extreme Networks AP7532.
• 6 units total - 4 of the external antenna variant, 2 with internal antennas

Alias	Network Hostname	Location	IP address
office_2ndfloor	ap_office_2f_controller	Office, 2nd floor (I.S.)	172.30.18.80
office_1stfloor	ap_office_1f	Office, 1st floor (Reception)	172.30.18.82
dc_hhc	ap_dc_hhc	Home Health Care	172.30.18.84
dc_receiving	ap_dc_receiving	Unity Training Room	172.30.18.83
dc_largedown	ap_dc_largedown	Pillar, large down/fridge area	172.30.18.85
dc_alt	ap_dc_alt	Spare	172.30.18.86

Channels and antenna power

Wireless channels and output power are locked-in per AP. No auto is used (that would be a severe indication of technical incompetence).

On the 2.4GHz band, only the non-overlapping channels 1, 6 and 11 were used. 4 access points (see table above) are enabled for 2.4GHz, with the farthest 2 sharing the same channel. The intent is to keep wireless traffic on this spectrum to primarily serving RF gun usage, to prevent interference. For devices able to use 5GHz, performance is drastically improved on that band anyhow (802.11ac).

On the 5GHz band, there are more non-overlapping channels than there are access points, so channels were selected randomly. It is worthy to note that all channels are available for selection, but some are supposed to be for DFS use (e.g. channel 165). Mistakenly choosing one as the primary channel will cause most clients to not be able to connect to that radio.

Antenna output power was tuned from a semi-scientific process of detecting signal strength of the access points from different locations. If left at full power, 1 access point can blanket virtually 80% of the entire building with signal (albeit poor-quality signal at farther distances). Thus, it is ideal to restrict power to influence client-roaming to connect to the nearest AP for the best signal quality.

Controller

One of the APs (office_2ndflr_controller), is being used as a virtual controller - a WiNG feature that allows an AP to manage other APs. Due to the fairly beefy internal specs of a typical AP in the market today, this feature is being offered more and more by vendors, and is completely feasible for smaller deployments (e.g. the management of 5 other APs by this controller is actually well under the recommended maximum of 64 devices).

It is quite important to note that the term 'controller' in this scenario does not refer to a traditional wireless controller, where there is centralized traffic forwarding i.e. all wireless traffic passes through the controller, and the APs can't function without one. Rather, what we have is known as a distributed architecture, where the APs are independent and can function without a controller, yet their settings are configured and their stats are monitored by the adopting controller. This wireless architecture is highly efficient as it centralizes management but avoids a hardware appliance, which as a single point of failure would make for a less fault-tolerant setup.

Wireless Networks

These settings are provided here for convenience but may change at any time in the future. Log in to the web GUI to verify actual settings.

SSID	Purpose	Authentication	VLAN	office_2ndflr 2.4GHz	office_2ndflr 5GHz	office_1stflr 2.4GHz	office_1stflr 5GHz	dc_hhc 2.4GHz	dc_hhc 5GHz	dc_largedown 2.4GHz	dc_largedown 5GHz	dc_receiving 2.4GHz	dc_receiving 5GHz
uwd_dcrf	Warehouse RF Guns, Mobile printers (Receiving)	WPA2-PSK, shared key: uwdrf2051	1					on		on		on
uwd_guest	Guest Access	Captive Portal	2		on	on	on		on			on	on
uwd	Staff Access	WPA2-PSK, shared key: unipharm	2		on	on	on		on			on	on
uwd_z	Privileged/Admin Access	WPA2-PSK, shared key: visionit	1		on	on	on		on			on	on

Wireless security

WPA2-PSK was deliberately chosen for all networks (except the guest WiFi, which has a captive portal) as it is the best balance between convenience of administration, wireless performance, and security. Enterprise (e.g. 802.1x) was deliberately avoided - the company is just too small to warrant going down this road.

Advanced features

Wireless QoS and Fast Transition (802.11r) is something to be explored in the future if the plan to use VoIP cordless phones comes to being.

Administration

Web GUI: https://172.30.18.80

Login: (username/password found here)

Other Notes

Acquisition of Zebra

The WiNG platform was originally a product by Motorola (their mobile enterprise division), which was acquired by Zebra. Zebra evolved the platform for several years, then their WLAN portfolio was acquired by Extreme Networks. From discussions with Extreme Networks reps, it seems they plan to continue with the WiNG platform despite having their own wireless platform (ExtremeWireless). They did hint at integration of the two at some point, perhaps from a management standpoint (i.e. converging the software to be able to manage both types of APs).

WiNG vs WiNG Express

WiNG Express is a scaled down version of WiNG. The 7532 APs actually use WiNG Express as a default. Upon inspection, WiNG Express appeared too simplistic. A CLI command exists to switch to WiNG from the default WiNG Express.