Cisco CAPWAP controller ????

[Richard Tapley]

Hi,

Really sorry if this isn't the right place but am desperate for help!

Have applied for a dream job for me to get into networking but one of the things that they have asked for that I haven't heard of before is a Cisco CAPWAP controller, is anyone able to explain the basics or it for me?

From quick web search it seems to be a type of wireless access point!

Any info would be useful.

Thanks

Sent from Cisco Technical Support iPad App

[Daniel Ordóñez Flores · Accepted solution]

Hello Richard.

Well let me try to introduce it I'm not sure If I'm the best to write to you but I been study about this.

when you need to deployment a wireless networ you have two options use Autnomonous AP or Lightweight AP.

Waht the diferrence? Well in autonomous AP you need to configure one by one AP. I mean If you create a WLAN called "CIsco" you need to configure the SSID, security, VLAN, an so on.

If you use a lightweight AP you need a central devices to management the AP and your network this device is called Wireless Lan Controller. This AP use a protocol called CAPWAP befor LWAPP.

If you want it I have a book about this and I guess it can helps you.

[Daniel Ordóñez Flores]

CAPWAP

The controller-based solution allows the splitting of 802.11 functions between the controller-based AP, which handles real-time

portions of the standard, and the Cisco WLC, which handles items that are not time sensitive. This model is called split MAC .

The AP handles the portions that have real-time requirements, such as the following:

■ Beacons management

■ 802.11 encryption and decryption

■ Frame buffering for dozing stations

■ Probe responses

■ Air monitoring for interferences and rogues

The controller handles all other functionalities, such as the following:

■ 802.11 authentication and association

■ QoS and security management

■ Mobility (roaming) management

■ RF management

■ Bridging to and from the DS in the right VLAN

Lightweight APs (LAP) communicate with the controller using a specific protocol, Control and Provisioning of Wireless Access

Points (CAPWAP). The LAP encapsulates all 802.11 data frames received from a client into a CAPWAP frame. The data frame

portion is simply encapsulated into a CAPWAP frame, and is not encrypted by default (data part encryption is possible but optional).

The LAPs also constantly exchange encrypted CAPWAP control messages with the controller via the Radio Resource Management

(RRM) engine for real-time RF management, including

■ Radio resource monitoring

■ Dynamic channel assignment

■ Interference detection and avoidance

■ Dynamic transmit power control

■ Coverage hole detection

This come from a book wrote by Jerome Henry

[Richard Tapley]

Hi Daniel,

Thanks for the quick reply.

This has shown that my knowledge of wireless is lacking and after the ccna security maybe I should look at the ccna wireless :-)
I got the first post and understand what you explained but got a bit lost with the second.

So if I have this right it is used to manage many wireless access points and their associated config centrally put very basically?

Thanks again

Sent from Cisco Technical Support iPad App

[Scott Fella · Accepted solution]

A controller based solution indeed centrally manages the configuration for all access points that has joined the WLC.  It also manages the firmware and other features in a lightweight solution than what you can do with stand alone autonomous access points.  Its very hard to explain, unless you have experience with stand alone access points, then have touched a controller based wireless.

Thanks,

Scott

Help out other by using the rating system and marking answered questions as "Answered"

[Daniel Ordóñez Flores · Accepted solution]

Yes and not.

You can management the AP's with the WLC but it has many features.

For example: The AP and the WLC has communications all the time, if the AP has some interference for another devices like a micro-oven or cordless phone the AP say something like this " Ey!! WLC someone is using my frecuency. What can I do?"  The WLC just say change the channel that you're using.

Another example: When you use a  Internet on a Hotel sometimes you can see a webpage where you need to introduce an username & password. Well the WLC can do that.

A WLC is the best way to deploy a corporative wireless network.

[Leo Laohoo · Accepted solution]

After Cisco aquired Aerospace, they introduced to a market the term called LWAPP (light wieght access point protocol).  Basically it's the way how an access point talks to a the controller.  Later, IEEE ratified this protocol and out came a new "buzz" word called CAPWAP.  It's the same thing, except it no longer has the phrase "developed by Cisco".

The beauty about controller-based AP (aka light weight access point), is that all configuration is done on the controller.  The APs basically becomes a very large antenna.  In some cases, you can configure each AP individually or you can configure the entire WLAN behaviour all by a simple GUI.

Like what Scott said, it's a difficult concept to understand if you don't have a WLC to play with, however, once you start getting comfortable with the GUI, it's not difficult to master it either.

If your organization hired you, even of your limited wireless knowledge, then it means that the company trust you will acquire knowledge to get yourself productive.  I recommend you the following stuff to read during your spare time:

1.  Enterprise Mobility 4.1 Design Guide;

2.  Cisco Unified Wireless IP Phone 7925G, 7925G-EX, and 7926G Deployment Guide < -- I know this is a PHONE deployment guide but IF you can influence your company to deploy VoIP-grade wireless then you won't have problems with roaming;

3.  Cisco Wireless LAN Controller Configuration Guide, Release 7.5 < -- How to configure a wireless LAN controller (WLC).  Good place to also know what your WLC can/can't do.

Do what Scott's doing, get a WLC for you to play with.

Also ask management if they can send you to wireless training.

Cisco Wireless Product Portfolio

[Leo Laohoo]

Wireless LAN Compliance Status < --- This document is very important.  A lot of novice deploying WLC make this mistake.  Basically, each country have their own law on what an individual can/can't use, particularly the free wireless frequencies and/or channels.  Like in some countries, you can't use 802.11a.

Say you are in America and you want to deploy APs both in America and in Germany but you want to use only one controller.

Your APs will need to have a "-A" regulatory domain for America but your Germany will have "-E" regulatory domain.  So this means that there's a chance some channels for the Germany AP will not work because only common channels between the two regulatory domain will be enabled.

[Richard Tapley]

That is fantastic information and has definitely helped a lot.

At least I now have a basic understanding where before I had nothing at all!

I am hoping that I can get the job on the knowledge and limited experience that I have and then learn quickly and prove that this really is what I want to do and do well. I have many friends who say go for every job that looks good as you never know when you will get get one even if you are lacking some or all experience as they go for what the person is like too and sometimes that can win over so fingers crossed :-)

I will look at the info suggested by all to get as much understanding as I can before my interview!

A huge thanks to all!

Sent from Cisco Technical Support iPad App

[Scott Fella]

Richard,

I do technical interviews for my company and I prefer that whomever I'm interviewing has knowledge of what they have in their resume. I like to know that someone is willing to learn, but I don't like if someone tries to BS me. Your better off showing them your interest and that your willing to learn. Also having a good attitude and showing the interviewer that you work well with others is a positive. You can read and learn from information provided and what's on the internet, but if I ask you questions on how many installs have you done or what products and code versions you have used, would you be able to answer that.

I started with really no design experience but was working as a support tech when I got the chance to go into consulting. I would rather hire an individual who is willing to learn and work well with our team than someone who thinks or maybe knows a lot, but has a bad attitude and might not fit in with our team. Experience is a plus, but we have hired engineer who have not had any wireless skills and now are working on their own wireless projects for large enterprise companies. Now it might of taken then 3+ years, but I'm comfortable with them and their work.

You seem like you have the will to learn and will do well if given a chance. Just make sure if you have a technical interview that you don't BS and you should do fine.

Good luck!

Sent from Cisco Technical Support iPhone App

[Richard Tapley]

Hi Scott,

Thanks for the info and I couldn't agree more on giving no BS! I believe you always get caught out!

I wasn't trying to BS them in my question just show interest, would you agree that is the right thing to do?

E.g. I had the interview yesterday (and not confident about how it went but that could just be me) and when it came to questions at the end I asked about wireless devices they used and mentioned that I hadn't had experience of CAPWAP (to be honest with them and not BS) but that I was very interested and that I had done a bit of research to just understand what they are and roughly how they work? Surely that must be a positive?

I am not confident I did well becuase they several times pushed for more details of some questions that I kind of ran out of details on I think mainly becuase I was nervous as it would be a fantastic opportunity becasue they use a lot of new technology in the networking world.

Sadly the only positive that I remember from the interview was the discussion I had with the guy that would be the manager of the new person about kit that I had at home to practice on (e.g. 1841 routers) and he said they use them with BT infinity lines for small branches and I said that was exactly what I setup when I got my BT infinity before progressing onto getting an ASA5505.

I just hope I showed what they needed and they give me the job to get the experience I need and want as I realy want the job now!

Thanks again

Would be interested on your thoughts on the above??

[Abhishek Abhishek]

Please refer to the link-

http://www.cisco.com/en/US/docs/wireless/controller/7.0/configuration/guide/c70lwap.html#wp1064295

[blenka]

CAPWAP :- Controlling and provisioning wireless access point.

this is the protocol used for associating AP & data tx Rx by the controller. even for managing the AP.

[Abha Jha]

You are right Richard.. Its a controller which manager all the CAPWAP/lightweight Access point.

All the configuration of Access point is done through controller and its a central unit which can controll hundreds to thousands of AP and we get the WIFI connectivity through this.. Hope this helps.

[Richard Tapley]

Hi All,

Just wanted to come back to say that..... I got offered the job I went for!! :-)

Still waiting for paper work but all going well I will soon be a ...... Network Infrastructure Specialist... sounds very grand to me but am looking forward to it so much, just to be able to do networking in a live environment and the role sounds fantastic from the breif description they gave me!!

Thanks for all of the advice above on the CAPWAP controllers am looking forward to seeing them in real life and getting to use and understand them!

Originally wasn't looking at the Wireless exams but have now decided to probably look at CCNA Wireless after my CCNA Security!

Thanks again all.