Month: October 2014
CCNP Wireless CUWSS 642-732 Summary Notes 1 : Site Survey Requirements for Different Vertical Industries
A site survey is a task-by-task process in which the surveyor studies the facility to understand the RF behavior, discovers RF coverage areas, checks for RF interference, and determines the appropriate placement of wireless devices.
- Identify Customer Requirements and his expectations. What type of environment?
- Consider the regulatory issues for that particular site
- Asses the network before deployment
- Consider logistics.
- Consider the models that we will use on the site Read the rest of this entry »
Thought I would put up a quick post regarding unit of measurements for the Maps.
CPI comes with feet as the default unit and this can be an issue for countries that use meters. I could always recalculate my length in meters and input it in CPI until a client made a rather rude comment like “we do not use feet in our country and I do not expect to see that in documents”. Ok, it was not rude, it’s a fact, but could he not put it in a different way? Read the rest of this entry »
Cisco Wireless: MSE Patch for Bash Code Injection Vulnerability , aka Shellshock [(CVE-2014-6271, CVE-2014-7169]
- Download the patch from Cisco.com
- Backup the MSE via cisco prime. Refer to my post step 12 and 13
- SSH to the MSE
- Stop the MSE software
- Copy the downloaded file, mse-bash-patch.zip to the /tmp directory on MSE
- Login to the MSE as root and navigate to /tmp directory
- Unzip the files
- Perform patch
- Start MSE
- Verify MSE status from
And that is all 🙂
Release Notes HighLights
Compatibility Matrix for version 8.0
Manual Site Survey
Passive manual survey – The radio card collects RF measurements but the client adapter is not associated to the access point during the survey, and all information is received from radio signals that exist at layer 1.
Active manual survey – the radio card is associated to the access point and has layer 2 connectively, allowing for low-level frame transmissions. If layer 3 connectivity is also established, ping traffic is sent in 802.11 data frame transmissions. RF measurements, packet loss and re-transmission percentage recorded.
Moth types of survey are recommended. Read the rest of this entry »
Indoor Site Surveys Tools
- Spectrum analyzer for RF spectrum analysis
- Blueprints or floor plans of the facility
- Received signal strength measurement tool
- 802.11 client card – prefer the vendor that will be deployed
- AP – preferably 2.
- Battery pack for AP and for the laptop
- Binoculars to view distant objects ( eg high ceiling and in the ceiling)
- Walkie-talkies or cellular phones for communication with site survey partners etc
- Antennas, both omni-directional and indoor semi-directional
- Temporary mounting gear – Bungee cords, plastic ties, duct tape, tripod
- Digital camera to record the exact placement of the APs and site specific information
- Measuring wheel (best p[tion) or laser measuring meter to measure cable distances
- Colored electrical tape to mark where AP was mounted. Advisable to use different colours for different channels.
- Ladder or forklift to mount the APs
A noisy environment can cause the data in 802.11 transmissions to become corrupted -> the cyclic redundancy check (CRC) will fail -> the receiving 802.11 radio will not send an ACK frame to the transmitting 802.11 radio -> the unicast frame is not acknowledged
and will have to be re-transmitted. Wi-Fi data networks can handle a retransmission rate of up to 10 percent, but a Voice over Wi-Fi (VoWiFi) network needs to limit packet loss to a rate of 2 percent or less. Read the rest of this entry »
A vertical market is a particular industry or group of businesses in which similar products or services are developed and marketed.
- Weather proof APs (eg ruggedized) may need to be deployed.
- Site Survey kits with Mesh APs may be needed.
- Consider the weather conditions. Most appliances will need to be protected from weather elements by using NEMA rated enslosure units (NEMA – National Electrical Manufacturers Association)
- Safety – hire professional installers.
- Consider RF considerations set by the local government.
Capacity and Coverage Requirements
Factors that should be considered when planning for Capacity:
- Data applications.
- For 802.11b/g network, 12 to 15 data users per AP
- SpectraLink recommends max of 12 calls per 11 Mbps cell (with 1 call needing 4.5 % of AP bandwidth), 7 calls per 2 Mbps (with 1 call needing 12% of AP bandwidth). This can be predicted using the Erlang Formula. Erlang – one hour of telephone traffic in one hour of time.
- User density. A high concentration of human bodies can attenuate the RF signal due to absorbtion.Consider:
- How many users currently need wireless access
- How many users many need connectivity in the future
- Where are the users
- Peak on/off use
- Existing transmitters
- Previously installed 802.11 network
- Interfering devices
- cordless headsets
- cordless phones
- wireless machinery
- Mobile vs Mobility
- When one is mobile – disconnect may be ok (moving with the laptop from one desk to another). roaming may not be a requirement.
- For mobility – user must be connected 100% of the time when travelling through the facility eg
- Warehouse scanning applications
- 802.11g protection mechanism. This will always affect throughput due to backward compatibility with 802.11b HR-DSSS clients that support a max data raet e of 11 Mbps as compared to 54 Mbps for the 11g clients.
Gather background data for the site survey
Examine business requirements
- Why do they need a WLAN
- is mobility required
- What devices will be connecting
- What apps will be used
- What is the amount of bandwidth required by the user
I hate it when Cisco comes up with a feature or new release of the WLC or the APs, and we have to wait forever to get support for MSE, CPI etc!! How are they supposed to function in the meantime??
The issue is that I have the new 3700 APs and now that am running CPI 2.0, I cannot manage or even see them without having to upgrade the CPI.
Anyway, at least I get to play with my toys 🙂
We can perform an inline upgrade of CPI from 2.0 to 2.1 without having to do a system migration. System migration is best and recommended because you perform a completely new installation then copy database. I however chose to take advantage of the inline upgrade because it’s easier 🙂 and I do not have to copy / re-host licences.
A Site Survey is an in-depth examination and analysis of a WLAN site.
Purpose of a Site Survey
- Achieve the best possible performance from the WLAN
- Certify that the installation will operate as promised
- Determine the best location for APs
- Develop networks optimized for a variety of applications
- Ensure that the coverage will fulfill the organization’s requirements
- Locate any unauthorized APs on the network
- Map any nearby wireless networks to determine existing radio interference
- Reduce radio interference as much as possible
- Make the wireless network secure