FAQ

Frequently asked questions and 7signal answers:

WLAN is not used for critical communications…?
Is it safe to use WLAN for business information?
How can you promise a SLA (service level agreement) for WLAN network? What does the SLA promise mean?
I have already a top class WLAN controller and wireless management software with it? Why would I need something else?
How does 7signal Site Miner differ from site survey and simulation tools, like ones from Ekahau, AirMagnet and Visiwave?
How does 7signal Sapphire differ from Wireless Intrusion and Detection (WIDPS) products, like AirMagnet, AirDefense and AirTight Enterprise products?
Can I use 7signal Sapphire to monitor wireless network of different vendors?
Does 7signal Sapphire automatically correct problems in the network?
I have a “power boost” function in my access points. Neighbor access point increases power if one fails. Isn’t that enough?
I have automatic RF channel allocation function in my controller. Is it sufficient?
I have 802.11n, isn’t that enough?
Cisco announced CleanAir technology recently. How does that relate to 7signal Sapphire?
How much does 7signal Sapphire cost?
Why have large Enterprise WLAN vendors not implemented performance and SLA management functionalities for their products already?
My company operates on several sites, some of them overseas. Can I use 7signal Sapphire for centralized monitoring?

WLAN is not used for critical communications…?

People are sometimes surprised, when they hear that WLAN is used in numerous business and even life critical applications and use expands all the time. Some examples

Hospital clinical information systems (point of care with laptop on cart, PDAs, life critical patient monitors, personnel safety and location)
Large warehouses and logistics operations (forklift terminals, handheld terminals)
Large enterprises use increasingly Voice over WLAN (Vo-Fi) communications. VoIP is very sensitive to network errors. Enterprises as well are moving to all wireless offices and achieve huge savings in LAN infra investments and maintenance.
Airport staff operative communications (gate communications, handheld devices with service crews, plane fueling staff, catering )
Harbors (vehicle and handheld terminals at cranes, straddle carriers, trucks, RFID gate readers)
On the more exotic side, for example mining machinery often is remotely operated over WLAN

Is it safe to use WLAN for business information?

Security used to be the top concern in WLAN networks and a lot of R&D has been put in to solve this. As of today, properly configured and planned WLAN networks are very safe. WPA2 encryption gives excellent security for the over the air communications. This may be complemented further with other technologies like VPNs and Wireless Intrusion Detection and Prevention Systems (WIDPS).

How can you promise a SLA (service level agreement) for WLAN network? What does the SLA promise mean?

SLA means that service quality is measured and reported continuously in a manner that that really reflects end user experience and network is also proactively maintained and optimized to keep this predefined quality level. Network optimization may mean network equipment parameter changes, cleaning and regulating local radio spectrum use, adding or moving equipment, changing WLAN antenna types, redirecting antennas, getting faults fixed in network elements, replacing equipment having a degrading performance over time and selecting optimal client devices to be used in the network. It is unfortunate but regularly WLAN networking equipment have software faults that prevent reliable and smooth operation. Detecting these is impossible without proper performance management solution.

I have already a top class WLAN controller and wireless management software with it? Why would I need something else?

If your network end users are continuously satisfied for the WLAN services or possible intermittent connection problems in network do not bother, you likely don’t need else. If you operate WLAN in critical environment, you usually have to be able to maintain network performance constantly at the predefined high level. Network performance management and application service level management (SLA) functionalities are missing from WLAN controllers. They provide no visibility to service quality from end user perspective. As a result, maintenance and fault process is most often triggered by end user fault reports after the problem has already emerged. Every wireless and wired network needs optimization and maintenance. Without continuous visibility to end-to-end network performance, network optimization is difficult or even impossible. 7signal Sapphire complements WLAN controllers, WLAN management software and LAN/WAN element manager solutions in business critical networks by adding the missing performance and service level management functionalities.

How does 7signal Site Miner differ from site survey and simulation tools, like ones from Ekahau, AirMagnet and Visiwave?

WLAN planning (site simulation, on a laptop/desktop) tools are used to simulate signal strength (coverage) and signal-to-noise ratio (SNR) within a planned network and find optimal locations for access points and power level settings. Site surveys tools (on laptops) are analyzers that map coverage and signal-to-noise (SNR) within already existing or recently built network in a snapshot manner at the time of measurement. 7signal Site Miner is a verification, validation and troubleshooting tool. It does not replace the need for site simulation and site survey tools with new network planning. They are necessary for every professional network build up. 7signal Site Miner provides capability to verify over a longer period of time (days-weeks) that built network performs at expected level before rolling out critical services to it. With history data, Site Miner also helps to identify bottlenecks impacting negatively to user experience and find correct improvement actions. In critical networks, post-installation verification is a necessary phase and 7signal Site Miner automates this data collection.

How does 7signal Sapphire differ from Wireless Intrusion and Detection (WIDPS) products, like AirMagnet, AirDefense and AirTight Enterprise products?

One focuses on security and another on network performance and service levels. WIDPS solutions focus on security and remote troubleshooting functionalities. 7signal Sapphire Wireless Quality Advancement (WQA) solutions focus on end user experience, network performance in wireless and wired networks, SLA management. 7signal Sapphire uses highly advanced Eye stations with a large coverage and additional capabilities compared to standard access point sensors with omni-directional antennas. See 7signal site product pages for a more accurate comparison of capabilities.

Can I use 7signal Sapphire to monitor wireless network of different vendors?

Yes, 7signal Sapphire is vendor agnostic/neutral. It supports different vendors and different equipment generations.

Does 7signal Sapphire automatically correct problems in the network?

7signal Sapphire or no other system is able to correct severe problems in the network by itself. These may emerge in the form of interfering devices, lacking coverage, lacking capacity, hardware faults in access points or antennas, faults in end user devices, software faults in network equipment (WLAN/LAN/WAN) and configuration errors to name a few. Common interfering devices include uncoordinated neighbor WLANs, Bluetooth devices, wireless video cameras, baby monitors, microwave ovens and motion detectors. 802.11e (QoS) and some related WLAN vendor specific implementations provide a capability to allocate different amount of resources for different clients and applications. While this give a little bit more room for critical clients/applications to breath, it does not impact to overall capacity at all. In worst case, lower priority clients get practically no service at all. Sapphire enables proactive WLAN network management that is necessary to let professional network managers to take care of the above mentioned issues.

I have a “power boost” function in my access points. Neighbor access point increases power if one fails. Isn’t that enough?

If the initial network plan is done with necessary overlap with access point coverage areas and initial access point power levels have been reduced about 6 dB (from 20 dBm to 14 dBm), then this strategy might provide some help for a case where access point fails completely. However, total access point equipment failure is not the typical reason for network issues and power boost cures only that. Reasons reside more often in radio environment, network parameters and also software faults in network equipment. For this reason, this significant overlapping RF coverage strategy might not be worth of investment. It is important also to remember that even though access point output power increase improves client receiving levels, it does nothing for client signal levels at access point.

I have automatic RF channel allocation function in my controller. Is it sufficient?

Automatic channel control functionalities have turned to underperform in current implementations. This feature provides some benefits in a case there is only one or few clear interferers that may be avoided by channel a change. Local optimization resulting from the current implementation of this feature does not often deliver expected outcome. One automatic change triggers another change in the neighbor access point and this process continues. Access points in the possible neighbor network, having the same feature, start its own process. This leads to an uncontrolled and harmful “oscillation” in network settings. 7signal is experience has shown that network managers with proper tools do a superior job compared to current automated implementations.

I have 802.11n, isn’t that enough?

802.11n does provide more throughput and capacity. As well coverage is improved if client devices support MIMO. 802.11n does not provide any additional capability to manage network performance.

Cisco announced CleanAir technology recently. How does that relate to 7signal Sapphire?

It is very good to see that WLAN quality aspects start to gain attention! Cisco CleanAir is a spectrum analyzer and vector signal analyzer capability integrated to a new access point model. It measures radio spectrum, when the access point is not transmitting. It also indentifies sources of non-WLAN interference and prefers using channels that have less interference. Functionally new things are improved automatic radio channel selection algorithm and identification for the source and location of interferer (microwave oven, baby monitor, Bluetooth, etc). As opposed to 7signal, Cisco CleanAir does not provide any visibility on what kind of service quality network provides for end users, it cannot monitor SLA levels and it does not cover other than radio connection part. It also requires all access points to be replaced in the network and does not work in multivendor environments. 7signal Sapphire has also spectrum analysis capability integrated into it. 7signal is already looking for an opportunity to see impact of CleanAir in a live network. 7signal Sapphire performance metrics before and after the roll out of CleanAir access points will tell the difference in end user experience in a live network.

How much does 7signal Sapphire cost?

Compared to Enterprise WLAN network equipment without installation labor costs, cost of Sapphire WQA is about 15-20%. When installation labor is included, additional investment is clearly smaller, typically below 10%. Only one Sapphire Eye is needed for every 6-12 access points, so the roll out is fast. With new networks, avoiding the need for unnecessary overlapping coverage (= more access points just in case one fails), deploying 7signal Sapphire provides savings already in first investment by decreasing the amount of needed access points and associated controllers and software licenses. Efficiency of network managers is significantly improved with centralized and remote troubleshooting capability. This alone results a payback time of 6-12 months. The biggest benefit of course is that people can perform their work as planned. The cost of downtime or lacking speed may provide almost instant payback.

Why have large Enterprise WLAN vendors not implemented performance and SLA management functionalities for their products already?

We have been asked this many times and we have no clear answer. In wired (LAN/WAN) networks there are already solutions in place from vendors like Netscout and Shunra. It seems obvious that next the weakest link of all, the radio connection, needs to be included as well. It seems that general focus has been on security and enhancing the maximum throughput over radio connection. It also seems that now the focus is turning more towards WLAN performance and capability to deliver continuously good user experience. There are several studies (for example from Aberdeen group) indicating that network performance and efficient management of resources are the most urgent issues to solve today.

My company operates on several sites, some of them overseas. Can I use 7signal Sapphire for centralized monitoring?

7signal Sapphire supports fully managed service provider environments, operator networks and large enterprise use. One central Carat server can handle multi location networks and isolate completely different organizations. One Carat is sufficient even for very large deployments, typically 1000-2000 Sapphire Eye stations, each measuring 6-12 access points.