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ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Welcome to the Cisco Networking Professionals Ask the Expert conversation. This is an opportunity to get an update on Wi-Fi such as antennas, PoE, standards, installations and more with Cisco expert Fred Niehaus. Fred is a Technical Marketing Engineer for the Wireless Networking Business Unit at Cisco Systems, Inc. He has extensive customer contact and is responsible for developing and marketing enterprise class wireless solutions using Cisco Aironet and Airespace Series Wireless LAN products. He has actively participated in some of Cisco's largest Wireless LAN deployments in education and retail with such customers as the New York Board of Education and the Home Depot stores He has served as technical editor for several Cisco Press books including: Cisco 802.11 Wireless Networking Reference Guide by Toby J. Velte; The Business Case for Enterprise-Class Wireless LANs by David Castaneda, Oisin Mac Alasdair and Christopher Vinckier; Wi-Fi Hotspots Setting Up Public Wireless Internet access by Eric Geier; and 802.11 Wireless Network Site Surveying and Installation by Bruce Alexander. Prior to joining Cisco's Wireless Networking Business Unit, Fred worked as a support engineer for Telxon Inc. supporting some of the very first wireless implementations from customers such as Wal*Mart, Ford, Hertz Rent-A-Car and others. He has been in the data communications and networking industry for the past 20 years and holds a Radio Amateur (Ham) License "N8CPI". Between 1983 and 1995, prior to joining Cisco, Fred was a senior technical support engineer for Tecmar Inc. one of the first companies to offer aftermarket products for the Apple and IBM Personal Computers.

Remember to use the rating system to let Fred know if you have received an adequate response.

Fred might not be able to answer each question due to the volume expected during this event. Our moderators will post many of the unanswered questions in other discussion forums shortly after the event. This event lasts through March 27, 2009. Visit this forum often to view responses to your questions and the questions of other community members.

37 REPLIES
New Member

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Fred,

Can you tell us, will the 1140 APs be supported in the 4.x train of code or will we have to upgrade to 5.x?

Thanks.

Hall of Fame Super Gold

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

You'll need to upgrade the WLC firmware to the 5.2.X to get the 1140 to work.

Cisco Employee

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Correct, see previous post regarding code trains.

Cisco Employee

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Q1: Can you tell us, will the 1140 APs be supported in the 4.x train of code or will we have to upgrade to 5.x?

A1: I can only offer you my opinion on this. As I recall it, we had considered supporting 1140 APs on the 4.x train however; given the lack of full RRM support for 802.11n (40 MHz wide channels, etc) within 4.x code train, therefore it could not be reasonably done without introducing a significant delay in the product release.

Also, to add 1140 support was not trivial as there was a danger that retrofitting 802.11n RRM support into 4.2 could have run the risk for severe destabilization of our present 4.2 customers without doing significant regression testing which again, would have likely delayed the product further. We didn't make this decision lightly, I simply believe that...

Given customer's desire for a small integrated antenna AP that can run from 802.3af, (sooner then later) I can only offer a guess that we simply could not have done it without introducing a longer delay in the product release. So a business decision was made to allocate engineering resources on new features to newer code streams. So unfortunately; customers wishing to use the new 1140 APs will need to upgrade from the 4.x train.

Hall of Fame Super Gold

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Question: I understand that the 1140 is released in LWAPP-only IOS. Is there any provisioning to release an Autonomous mode IOS?

Cisco Employee

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Yes we have plans to release a version of Autonomous IOS (aIOS) code soon. We are targeting a beta in May with code release in June/July time frame.

I do know many partners like to use the aIOS version for site surveys and smaller deployments so we are working hard to get this out quickly.

New Member

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Will the AIR-LAP1142N be able to run the aIOS code without any hardware upgrades?

I'm very much looking forward to this beta.

Cisco Employee

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Yes the LAP1142N is certainly able to run the aIOS code without any hardware upgrades.

Hall of Fame Super Gold

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Thanks for the response. +5

Cisco Employee

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Sure thing.. Thanks.. Fred

Hall of Fame Super Red

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Hi Fred,

First off, thanks for taking the time out of your busy schedule to address these questions! Much appreciated!

Can you please tell us how our investment in the 1140's is protected, given the fact that there are still references to "802.11n **draft 2.0 compliant" in all of the docs that I have seen?

With the 1250 series the radios are modular and can be changed out in the event that the 802.11n draft 2.0 is not ratified (by the IEEE I guess:)

We are looking at adding 200 to 300 of the 1140's in the next year and we must ensure that we have done our "due diligence" when it comes to making this type of investment.

Thanks for your help here!

Rob

Cisco Employee

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Q1: First off, thanks for taking the time out of your busy schedule to address these questions! Much appreciated!

A1: Certainly, happy to respond.

Q2: Can you please tell us how our investment in the 1140's is protected, given the fact that there are still references to "802.11n **draft 2.0 compliant" in all of the docs that I have seen?

A2: Yes - Cisco's current 802.11n products are based on the IEEE 802.11n Draft 2.0 version of the 802.11n spec.

Cisco has built our products to the 802.11n Draft 2.0 specification because that's the version the Wi-fi Alliance has adopted for their 802.11n certification program. What this means is that all legitimate industry vendors are building products to the Draft 2.0 specification, not the newer drafts. The Wi-fi Alliance certification gives customers the assurance of interoperability between their infrastructure and client components. If the Wi-fi Alliance moves to certify based on a newer version of the 802.11n Draft specification, Cisco will support the newer version. However, the Wi-fi Alliance's stated direction is to only change the version for certification only when the final specification is ratified.

There is precedent here. The Wi-fi Alliance is following the model previously used with the 802.11i and 802.11e specifications.

By the way, if we look at later drafts it appears they are addressing primarily consumer devices like HDTV (in homes) a few optional features for hand-held certifications, So for now we are closely monitoring these but we do not expect any changes to the draft to require hardware changes.

Q3: With the 1250 series the radios are modular and can be changed out in the event that the 802.11n draft 2.0 is not ratified (by the IEEE I guess:)

A3: When we designed the AP-1250 we did so knowing the IEEE specification was early and planned for a potential radio upgrade. This is not new to Cisco, when the 802.11g was new (and not yet ratified) the AP-1200 series at the time had a "trap door" that allowed that module to be swapped out (upgraded as well).

As our comfort level increased, (with 802.11g) we designed the integrated radios inside the AP1240 and AP1130. Now that the draft 2.0 has been out, is stable and the Wi-Fi alliance as adopted it for their certification program we feel comfortable introducing the AP-1140 with integrated radios.

Q4: We are looking at adding 200 to 300 of the 1140's in the next year and we must ensure that we have done our "due diligence" when it comes to making this type of investment.

A4: For an update on 802.11n check out the following URL

http://www.cisco.com/en/US/prod/collateral/wireless/ps5678/ps6973/white_paper_c11-457039_ns767_Networking_Solutions_White_Paper.html

Hall of Fame Super Red

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Hi Fred,

Thanks for this excellent, detailed answer! As always, when I read these type of answers from you, I feel very re-assured with the direction we are going :)

Sorry for the non-technical question, but this information is key to our decisions moving forward.

+5 points for this kind reply!

Cheers!

Rob

Silver

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Hi Fred,

1. Power is a huge limitation in 802.11n, and I was pleasantly shocked when I saw that the 1140 can run on 802.3af power at full functionality. Are there any plans to modify the 1250 series so it can operate equally well on 802.3af? Is there a simple explanation for how Cisco managed to create an 802.3af fully-functional 802.11n AP?

2. As LWAPP 802.11n APs are added in increasing numbers, it seems to me that the bandwidth on WLCs will be insufficient for tunneled traffic. Quick math shows:

4404 = 4Gbps of BW

100 x 1240s @ 20Mbps average = 2Gbps

100 x 1250s @ 150Mbps average = 15Gbps

Obviously, this is when the AP is at its max capacity, but this is also for only one radio. If it only barely exceeded the maximum bandwidth, I wouldn't be concerned, but this is a LOT of potential traffic getting tunneled through the network and through the controller.

I guess my question is this - do you have any thoughts about the design philosophy of LWAPP with regards to 802.11n? Will we move away from a "tunnel all traffic" design to an H-REAP dominated design?

Thanks so much in advance.

Jeff

Cisco Employee

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Q1. Power is a huge limitation in 802.11n, and I was pleasantly shocked when I saw that the 1140 can run on 802.3af power at full functionality.

A1: In a previous post, I indicated the reason we used removable radio modules on the 1250 was because at the time, we did not have the comfort level with

802.11n as we do now (since the .11n draft was new) and the potential for radio changes at that time was a real possibility. In my opinion, we had an obligation to protect customer investments and removable radio modules did that. Now that the WiFi alliance has certification processes for 802.11n and we feel the chances of hardware changes are unlikely the need for modular radios is less.

Now let's talk a bit about why the 1250 needs a bit more power with both radios then the (15.4 Watts) 802.3af provides.

802.11n MIMO technology requires several radios (unlike the older Access Points) that had a single transceiver (transmitter/receiver) per band the new .11n APs have three receivers and two transmitters per band for a total of 4 transceivers and 2 receivers (6 radios) now add to that the additional processing power, RAM and GigE power requirements and you quickly approach 15.4 Watts (802.3af) now add the additional PCI circuitry to support removable radios and you need to make a decision, do you support removable radios or do you support 802.3af?

When the 1250 was in the design stages, some believed the newer higher power 802.3at spec would move along as quickly as the 802.11n spec did. There as also thought that a removable radio approach in a PCI design allowed for things not yet done, for example perhaps a WiMax radio, GPS, Fiber interface, Spectrum intelligence radio, mini-controller, a 4.9 GHz or new TV band spectrum radio etc.... any of these and more could all be potentially added to the 1250 via the module process.

However the 802.3at spec like the economy crawled, and demand for an 802.3af AP with integrated antennas drove the business decision and engineering focus on same.

Q2: Are there any plans to modify the 1250 series so it can operate equally well on 802.3af?

A2: Most Cisco powered switches that can do 802.3af can also produce the extra power to run the AP1250 that's the value add of using a Cisco end to end infrastructure. Customers who can not take advantage of the extra power within Cisco devices may use the AP-1250 with one radio or using two radios with some reduction in functionality.

Q3: Is there a simple explanation for how Cisco managed to create an 802.3af fully-functional 802.11n AP?

A3: Yes we gained the extra power by reducing the components used in the "removable radio design" and while adding more RAM to the 1140 we were able to gain some additional power using a processor that used slightly less current (power).

Regarding your second question.. throughput... I'll have to post that separately -

Cisco Employee

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Q3: As LWAPP 802.11n APs are added in increasing numbers, it seems to me that the bandwidth on WLCs will be insufficient for tunneled traffic. Quick math shows:

4404 = 4Gbps of BW

100 x 1240s @ 20Mbps average = 2Gbps

100 x 1250s @ 150Mbps average = 15Gbps

Obviously, this is when the AP is at its max capacity, but this is also for only one radio. If it only barely exceeded the maximum bandwidth, I wouldn't be concerned, but this is a LOT of potential traffic getting tunneled through the network and through the controller.

A3: Ok, I'll share my thoughts on this...

You are making the argument that at some point over-subscription occurs... So let's talk about that....

Cisco defined how switched and routed campus networks are designed and built using hierarchical network design. Specifically, the entire industry understands the simple, multilayer campus design concepts of access, distribution, and core layers because that's how Cisco taught people to build campus networks. Cisco customers and partners have been successfully using these design concepts for years. As such, these design concepts are fully vetted and mature. Campus design documents can be found at this URL:

http://www.cisco.com/en/US/partner/netsol/ns340/ns394/ns431/networking_solutions_design_guidances_list.html

Multilayer campus design guidelines for over-subscription of the uplink from the access layer call for an over-subscription rate between 8:1 and 20:1. However, in real world deployments, it's not unrealistic to see Cisco customers deploying at 50:1 or even 100:1 over-subscription of the uplink from the access layer. There are many reasons why Cisco customers have deployed at these over-subscription rates but the germane point is that customers have successfully deployed with these over-subscription rates and been satisfied with network performance. I'm not aware of many customers that exceed the capacity of our current controllers but rest assured, if they do we will have solutions to address that..

Q4: I guess my question is this - do you have any thoughts about the design philosophy of LWAPP with regards to 802.11n? Will we move away from a "tunnel all traffic" design to an H-REAP dominated design?

A4: While I'm prohibited from talking about "futures" with regard to the design philosophy, I don't feel there is any need to move away from what we are doing today and of course you can always augment with an H-REAP design if you really are exceeding the capacity of today's controllers.

Cisco Employee

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Your welcome.. Thanks for the kind words.

Silver

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Thanks Fred! That really does help, and I appreciate the time you put into answering my questions.

One more thing - I just heard about the 5500 controllers for the first time. Can you shed any light on these guys for us? Is there any official documentation about them yet?

Cisco Employee

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Q1: One more thing - I just heard about the 5500 controllers for the first time. Can you shed any light on these guys for us? Is there any official documentation about them yet?

A1: Few ground rules on forums (as they apply to me).... I'm not permitted to comment on futures, company direction, unreleased or potential products or ideas that may or may not eventually be committed products. I have no idea about your specific question and would suggest reaching out to your Cisco Account Rep for questions like this as it just confuses forum readers trying to "guess" what we are doing next... Although this forum is for discussion around the 1140 series Access Point, I'm happy to answer questions regarding current products or deployments I just can't address questions that offer speculation.

Silver

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

That's fine, I thought maybe they were closer to production than they apparently are.

New Member

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Q.Hi i have 2811 router with 4ports POE switch module and i am not using this device for any purpose,now i want to use this router and only 4ports POE to connect my IP phones,so how can i use it,if i need any config pls let me know...

Cisco Employee

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Since this forum is on Wireless and Wireless LAN products, it might be best to refer you to the URL on the 2811 where there is some good information and a method to contact support for same.

http://www.cisco.com/en/US/products/ps5881/

Cisco Employee

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Again, I can't comment but I will say that often new releases are announced at Networkers. For more on Networkers see the following URL: http://www.cisco.com/web/learning/le21/le34/learning_networkers_home.html

New Member

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Fred,

I have some 1142 APs on order, and I have some installation questions. I need to install them about 6 ft above

the ground in the middle of our factory floor. This is not ideal, but otherwise they would have to be about 60 ft high due to a crane. If I should mount them at 6 ft, should they be facing up or down for optimum antenna performance ? On the other hand, do you think I should forget mounting them low and go with the 60 ft high option. The building is 300 W x 700 L x 60 H. Access is obviously quite difficult when they are that high, so I need to have good cause for mounting them that way. Any advice would be appreciated.

Randy

Hall of Fame Super Gold

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Randy,

The 1140 AP is not designed to be used in a wide-open space like a factory/warehouse/hangar. For environment like yours (please correct me if I'm wrong here Fred), you need the 1250.

Cisco Employee

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Well the AP-1250 does give you more antenna options.. with antenna connectors. If you had shelving (think large warehouse) in some deployments small 10 dBi Yagi antennas on the wall shooting down the aisles work much better because there are physical obstructions between the user and objects on the ceiling.

I wouldn't rule out the 1140 it really depends on the application and environment. Also nothing prevents you from doing a hybrid approach using the best AP for the area deployed.

Cisco Employee

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

If you look at the AP logo / LED light that part should be pointing down toward the users. The integrated antennas (six of them) are all designed to radiate best

from an type of deployment as the antenna radiates DOWN and OUTWARD in a 360 degree pattern.

Best coverage is when the AP is closest to the actual users, if you mount them really high on the ceiling the signal has to travel that extra height (distance) as the AP is naturally further away from the users.

Try moving some data (pinging with large packets) and see what coverage you actually have at 6-8 Ft and then characterize how it looks higher in the ceiling.

Ideally you want the AP at 6-8 Ft and close as practical the users but reasonable success can happen with the AP higher. Avoid mounting the AP on a wall or upside down with the metal plate (down toward the user) - because if you do that the radiation pattern is not ideal. Wall mounting works best with the coverage area needed is less such as classrooms, small conference rooms kiosks etc.

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Dealing with multipath is big concern of mine - if you assuming I am running a 4402 with 5.2.178.0 code, what features/options do I need to enable/disable in order to get the best benefit to legacy clients (in my case 802.11b/g specifically)? At this point, no 802.11n clients will be connecting.

Thanks in advance...

Cisco Employee

Re: ASK THE EXPERT - CISCO AP-1140 ACCESS POINT

Multipath is something that is handled in the radio firmware (antenna diversity) so the best thing to do to mitigate multipath is to check the physical AP installation. You want the APs to be as close to the users as possible/practical. Also avoid locating the Access Point or the AP antennas near metal objects like "I" beams and metal filing cabinets. Smaller cell sizes help in high multipath areas.

Also the use of 802.11n Access Points such as the AP-1250 and AP-1140 can also help with legacy clients as they have extra receivers so rather then switching back and forth between antennas, the AP actually hears concurrently on each antenna and this results in connectivity performance in areas of high multi-path.

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