Wireless-only Dorms?
Wondering if anybody is moving forward with residential halls that are 100% wireless only, with no wired connectivity. If so, how is it working out? Regards- Lee Badman Lee H. Badman Network Engineer CWSP, CWNA (CWNP011288) Computing and Media Services (NSS) 250 Machinery Hall Syracuse University Syracuse, NY 13244 (315) 443-3003 Voice (315) 443-1621 Fax ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
Re: [WIRELESS-LAN] Wireless-only Dorms?
I would be interested as well. We have the access points and will probably install them over the winter break. Michael H. Bean PC Technician Information Services University of Saint Mary 4100 South 4th Street Leavenworth, KS 66048 682-5151 ext. 6999 Email: [EMAIL PROTECTED] [EMAIL PROTECTED] 11/9/2005 6:50 AM Wondering if anybody is moving forward with residential halls that are 100% wireless only, with no wired connectivity. If so, how is it working out? Regards- Lee Badman Lee H. Badman Network Engineer CWSP, CWNA (CWNP011288) Computing and Media Services (NSS) 250 Machinery Hall Syracuse University Syracuse, NY 13244 (315) 443-3003 Voice (315) 443-1621 Fax ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
RE: [WIRELESS-LAN] Wireless-only Dorms?
Theresa is absolutely correct. Installing wireless only dorms to students that expect and are used to broadband wired access is not trivial and requires careful planning and policy setting. A typical 802.11b AP is analogous to a half duplex 10 Mbps ethernet connection from yesteryear... However, the value of having broadband wireless access has many advantages and if done right will be the envy of other students. Not being tethered to a wall jack while gaming or internet/research access, or using wireless skype handsets for near toll free calling is very appealing to students. The initial design needs to consider coverage AND capacity. What applications multiplied by the number of users will dictate the capacity (high BW requirement app's such as gaming or music/video streaming, VoWLAN, etc). Generally, designing for capacity in high BW environments will yield good coverage, and any remaining coverage holes can be filled after a good site survey analysis. Setting and managing a good policy is also important. Security and access measures, support for 802.11a/g limiting 802.11b access, permitted hardware (everyone's lives will be easier if you only allow enterprise class wireless NIC's), etc. The ironic part is that if you do provide wired access, you can expect that students will plug in their own AP's, which is probably the biggest security threat (insecure rogue AP's creating network holes). It can be done, but it is not trivial and the more planning and upfront work done will reduce headaches in the future. Since you are probably enticed by the thought of 802.11n, it is not a good solution until the standard is released and enterprise class AP's are available (2 years away?). The devices today are NOT enterprise class and are not standards compliant. If you limit the WLAN to 802.11a/g only, you will have multiplied your capacity several times over an 802.11b network and be taking advantage of all that BW at 5 Ghz... My two cents... -Original Message- From: Theresa M Rowe [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 09, 2005 8:37 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Wireless-only Dorms? We have wireless-only dorms. We have more complaints from those areas than we do from our new student apartments, which are a mix of wire and wireless. There are issues. First, you need greater density of wireless access points than you do in other campus areas. Student build lofts and have bookcases, and there are lots of corners that all add up to problematic coverage. Students like to play games and do other kinds of high bandwidth activities that are not necessarily compatible with shared bandwidth access points. Students expect wireless in their living area to perform like the cable modem or DSL they had at home. You have to have strong messaging about the right network cards for your environment. You need to have a strong replacement cycle. We are on our second generation and we find that student appetite for bandwidth creates technical obsolescence for wireless faster than wired ports. All the other problems we have are more related to insatiable bandwidth appetite more than wireless. Theresa Rowe Assistant Vice President University Technology Services www.oakland.edu/uts - the latest news from University Technology Services ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
anyone using avaya ap-8 or proxim 4000?
Hi All I'm using avaya ap-8's which is the same as the proxim4000 unit. A request came in to have the box act as a NAT box. I had thought this was not possible, but I see NAT listed as one of the options on a few sites on the Internet. Is anyone using these boxes, and if so, do you know if they have router/nat capabilities? Thanks Matt [EMAIL PROTECTED] ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
Re: [WIRELESS-LAN] Wireless-only Dorms?
Phil Raymond wrote: The initial design needs to consider coverage AND capacity. Phil (and others), Have you got a rule of thumb for the number of students per G access point in a college dorm? Larry Press ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
RE: [WIRELESS-LAN] Wireless-only Dorms?
If someone forced me to assign a rule of thumb at this high level, I would assign a conservative data rate of 1 Mbps to each student as a requirement. For an 802.11g ONLY network running at the highest data rate (aka strongest signal) using enterprise class AP's (data thruput does vary between AP vendors, be careful here), you should expect to get 15-20 Mbps of upper layer thruput per AP. That would yield 15-20 students per AP. For 802.11a, this will probably hold. For 802.11g, due to the limit of 3 channels, you will get an overall reduction in capacity due to shared bandwidth between AP's in a densely deployed AP environment. Also, this assumes that you design the network for the highest signal strength - a very important point. In most instances this won't be possible due to the environment. Thus I would reduce the available bandwidth by 33% and say that 10Mbps is available. Hence I would go with the low end of 10Mbps available per AP. To take this to a lower level of analysis, I would want to know what applications the students would be running. Perhaps you use the analogy of a low end DSL connection that provides 768Kbps downlink and 128kbps uplink. Then you stick with the 1 Mbps/student and assume it supports most if not all applications they will use. You might also consider a swag at peak operating times (evenings) and assume ~50% of the available students are online (simple queuing theory assumption). Then you could say that a single AP would cover minimally 20 students. There is my rule of thumb at this high level. I would consider it conservative if you design the network properly. In a typical dorm with a lot of walls (and bookcases...), you will probably find that your coverage requirements and capacity requirements will be in alignment (and thus balanced). What I mean by that is that you will find that in order to provide a good signal in a dorm environment you will need to place a denser AP deployment (due to the thick walls, etc.). This means that as a consequence your capacity will also be increased due to the denser deployment. Other factors not considered here are the use of client cards. Performance between different manufacturers (you get what you pay for) will vary. Some cards will be noisy and interfere, others will have higher SNR requirements, etc. Hope this helps and not confuses - as I said, it is not a trivial subject. -Original Message- From: Larry Press [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 09, 2005 9:51 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Wireless-only Dorms? Phil Raymond wrote: The initial design needs to consider coverage AND capacity. Phil (and others), Have you got a rule of thumb for the number of students per G access point in a college dorm? Larry Press ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
Re: [WIRELESS-LAN] anyone using avaya ap-8 or proxim 4000?
You are correct in your belief that these units are simply bridges. Proxim does have a new controller, though, that will turn our AP-4000 installations into a switched wireless infrustructure, similar to Airespace/Aruba/Meru deployments. I have not looked at this, however it seems possible that this box may be able to do NAT for the clients. --Mike Matt Ashfield wrote: Hi All I'm using avaya ap-8's which is the same as the proxim4000 unit. A request came in to have the box act as a NAT box. I had thought this was not possible, but I see NAT listed as one of the options on a few sites on the Internet. Is anyone using these boxes, and if so, do you know if they have router/nat capabilities? Thanks Matt [EMAIL PROTECTED] ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/. ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
RE: [WIRELESS-LAN] Wireless-only Dorms?
The other factor that shouldn't be ignored is the role that clients play in contributing to co-channel interference issues in dense deployment WLANs. It's relatively easy (albeit expensive) to design micro-cell AP configurations that maximize per-user bandwidth by reducing power output on the AP. However, it's much tougher to control power output at the client, both because some client adapters/drivers do not support this capacility and also because you need to touch the clients in order to do so. This problem is mitigated somewhat by the asymetrical nature of most client communications (more downstream than upstream bandwidth consumption) though this is beginning to change with more and more PtP applications. Also, while this problem wasn't as great an issue in the past when PC-Cards were used on notebook computers, the enhanced wireless capabilities of the latest notebook computer designs -- especially the quality of embedded antennas -- has the effect of making notebooks more powerful RF radiators. The other point I would make with respect to capacity is that it is essential to take advantage of all available spectrum. That means implementing multi-band abg access points and -- this is a tough part -- getting users to purchase notebooks with abg support. Although notebook manufacturers don't like to disclose numbers, I believe well over 85% of notebooks still ship with bg rather than abg interfaces, even though the incremental cost of abg is minimal. The good news is that it's not essential to get all of your users on 11a, but moving a significant portion of them makes performance better for everyone. dm -Original Message- From: Metzler, David [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 09, 2005 12:10 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Wireless-only Dorms? Nice synopsis, Phil. I would add that the issue about bandwidth overlap in densly populated areas can be partially mitigated by making sure you select a vendor that has the ability to automatically decrease power to reduce overlap. Some do this, some don't. -Original Message- From: Phil Raymond [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 09, 2005 8:58 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Wireless-only Dorms? If someone forced me to assign a rule of thumb at this high level, I would assign a conservative data rate of 1 Mbps to each student as a requirement. For an 802.11g ONLY network running at the highest data rate (aka strongest signal) using enterprise class AP's (data thruput does vary between AP vendors, be careful here), you should expect to get 15-20 Mbps of upper layer thruput per AP. That would yield 15-20 students per AP. For 802.11a, this will probably hold. For 802.11g, due to the limit of 3 channels, you will get an overall reduction in capacity due to shared bandwidth between AP's in a densely deployed AP environment. Also, this assumes that you design the network for the highest signal strength - a very important point. In most instances this won't be possible due to the environment. Thus I would reduce the available bandwidth by 33% and say that 10Mbps is available. Hence I would go with the low end of 10Mbps available per AP. To take this to a lower level of analysis, I would want to know what applications the students would be running. Perhaps you use the analogy of a low end DSL connection that provides 768Kbps downlink and 128kbps uplink. Then you stick with the 1 Mbps/student and assume it supports most if not all applications they will use. You might also consider a swag at peak operating times (evenings) and assume ~50% of the available students are online (simple queuing theory assumption). Then you could say that a single AP would cover minimally 20 students. There is my rule of thumb at this high level. I would consider it conservative if you design the network properly. In a typical dorm with a lot of walls (and bookcases...), you will probably find that your coverage requirements and capacity requirements will be in alignment (and thus balanced). What I mean by that is that you will find that in order to provide a good signal in a dorm environment you will need to place a denser AP deployment (due to the thick walls, etc.). This means that as a consequence your capacity will also be increased due to the denser deployment. Other factors not considered here are the use of client cards. Performance between different manufacturers (you get what you pay for) will vary. Some cards will be noisy and interfere, others will have higher SNR requirements, etc. Hope this helps and not confuses - as I said, it is not a trivial subject. -Original Message- From: Larry Press [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 09, 2005 9:51 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re:
Re: [WIRELESS-LAN] Wireless-only Dorms?
All of the issues listed here are great examples of the complex nature of designing an 802.11 environment with such stringent requirements. With only 3 channels, even if you plan very carefully and precisely control the output power of your APs, you're going to get channel overlap. This will further reduce your capacity due to the inherent collisions/retransmissions. Especially when you factor in the client devices. A client device transmitting on a channel will force any other device operating on the same channel that can hear it (APs included if course) to wait on it to complete its transmission before it can commence. So, you have to realize that, even though 2 APs may not be able to hear each other, a client card between them that can hear both of them will tie up available bandwidth on BOTH APs while it is transmitting. Further complicating matters is a situation where two clients connected to two different APs on the same channel can hear each other but not both APs. In such a circumstance, client 1 and the AP 2 (the AP client 2 is connected) may transmit simultaneously. When this happens the signals will interfere with each other upon reaching client 2, causing client 2 to be unable to decode the packet, forcing AP 2 to retransmit the packet. Complicated indeed! Guaranteeing signal strengh and bandwidth alotments is extremely difficult. And, this totally ignores the problems inherent with outside interference or the fact that the environment (bookshelves, etc) change on a regular basis, possibly forcing you to revisit your ever-so-finely-tuned RF plan. Interestingly enough, all these issues are also extremely relevant if you're interested in looking to deploy any sort of VoIP/WiFi (VoFi). I'd suggest that, if you're truly interested in providing coverage/bandwidth that takes a lot of these issues into account, you might want to take a look at the Meru Virtual AP architecture. The controllers in these systems keep track of every 802.11 device each AP can here and employ a pretty darn impressive scheduling algorithm for getting the most out of the available channel capacity. Not only that, but they actually control when clients are allowed to transmit, further removing unknowns from the RF use equations and improving channel usage and capacity. I believe they do this using the PCF, or Point Coordination Function, in the 802.11 spec... I've not seen any other wireless switch system that makes use of it near to the level that the Meru system does. It's pretty cool. We're in the process of deploying Meru as our second generation wireless overlay here at UTD, mainly to decrease the need for complex channel planning, individual AP configuration, and to support a future VoFi implementation. --Mike Phil Raymond wrote: If someone forced me to assign a rule of thumb at this high level, I would assign a conservative data rate of 1 Mbps to each student as a requirement. For an 802.11g ONLY network running at the highest data rate (aka strongest signal) using enterprise class AP's (data thruput does vary between AP vendors, be careful here), you should expect to get 15-20 Mbps of upper layer thruput per AP. That would yield 15-20 students per AP. For 802.11a, this will probably hold. For 802.11g, due to the limit of 3 channels, you will get an overall reduction in capacity due to shared bandwidth between AP's in a densely deployed AP environment. Also, this assumes that you design the network for the highest signal strength - a very important point. In most instances this won't be possible due to the environment. Thus I would reduce the available bandwidth by 33% and say that 10Mbps is available. Hence I would go with the low end of 10Mbps available per AP. To take this to a lower level of analysis, I would want to know what applications the students would be running. Perhaps you use the analogy of a low end DSL connection that provides 768Kbps downlink and 128kbps uplink. Then you stick with the 1 Mbps/student and assume it supports most if not all applications they will use. You might also consider a swag at peak operating times (evenings) and assume ~50% of the available students are online (simple queuing theory assumption). Then you could say that a single AP would cover minimally 20 students. There is my rule of thumb at this high level. I would consider it conservative if you design the network properly. In a typical dorm with a lot of walls (and bookcases...), you will probably find that your coverage requirements and capacity requirements will be in alignment (and thus balanced). What I mean by that is that you will find that in order to provide a good signal in a dorm environment you will need to place a denser AP deployment (due to the thick walls, etc.). This means that as a consequence your capacity will also be increased due to the denser deployment. Other factors not considered here are the use of client cards. Performance
RE: [WIRELESS-LAN] Wireless-only Dorms?
I believe that http://www.extricom.com/ does almost the same thing that Meru does. Has anyone compared/contrasted the two? Jamie A. Stapleton CBSi - Connecting your problems with solutions. FlexiCall: (804) 412-1601 Facsimile: (804) 412-1611 -Original Message- From: Michael Griego [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 09, 2005 12:47 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Wireless-only Dorms? All of the issues listed here are great examples of the complex nature of designing an 802.11 environment with such stringent requirements. With only 3 channels, even if you plan very carefully and precisely control the output power of your APs, you're going to get channel overlap. This will further reduce your capacity due to the inherent collisions/retransmissions. Especially when you factor in the client devices. A client device transmitting on a channel will force any other device operating on the same channel that can hear it (APs included if course) to wait on it to complete its transmission before it can commence. So, you have to realize that, even though 2 APs may not be able to hear each other, a client card between them that can hear both of them will tie up available bandwidth on BOTH APs while it is transmitting. Further complicating matters is a situation where two clients connected to two different APs on the same channel can hear each other but not both APs. In such a circumstance, client 1 and the AP 2 (the AP client 2 is connected) may transmit simultaneously. When this happens the signals will interfere with each other upon reaching client 2, causing client 2 to be unable to decode the packet, forcing AP 2 to retransmit the packet. Complicated indeed! Guaranteeing signal strengh and bandwidth alotments is extremely difficult. And, this totally ignores the problems inherent with outside interference or the fact that the environment (bookshelves, etc) change on a regular basis, possibly forcing you to revisit your ever-so-finely-tuned RF plan. Interestingly enough, all these issues are also extremely relevant if you're interested in looking to deploy any sort of VoIP/WiFi (VoFi). I'd suggest that, if you're truly interested in providing coverage/bandwidth that takes a lot of these issues into account, you might want to take a look at the Meru Virtual AP architecture. The controllers in these systems keep track of every 802.11 device each AP can here and employ a pretty darn impressive scheduling algorithm for getting the most out of the available channel capacity. Not only that, but they actually control when clients are allowed to transmit, further removing unknowns from the RF use equations and improving channel usage and capacity. I believe they do this using the PCF, or Point Coordination Function, in the 802.11 spec... I've not seen any other wireless switch system that makes use of it near to the level that the Meru system does. It's pretty cool. We're in the process of deploying Meru as our second generation wireless overlay here at UTD, mainly to decrease the need for complex channel planning, individual AP configuration, and to support a future VoFi implementation. --Mike Phil Raymond wrote: If someone forced me to assign a rule of thumb at this high level, I would assign a conservative data rate of 1 Mbps to each student as a requirement. For an 802.11g ONLY network running at the highest data rate (aka strongest signal) using enterprise class AP's (data thruput does vary between AP vendors, be careful here), you should expect to get 15-20 Mbps of upper layer thruput per AP. That would yield 15-20 students per AP. For 802.11a, this will probably hold. For 802.11g, due to the limit of 3 channels, you will get an overall reduction in capacity due to shared bandwidth between AP's in a densely deployed AP environment. Also, this assumes that you design the network for the highest signal strength - a very important point. In most instances this won't be possible due to the environment. Thus I would reduce the available bandwidth by 33% and say that 10Mbps is available. Hence I would go with the low end of 10Mbps available per AP. To take this to a lower level of analysis, I would want to know what applications the students would be running. Perhaps you use the analogy of a low end DSL connection that provides 768Kbps downlink and 128kbps uplink. Then you stick with the 1 Mbps/student and assume it supports most if not all applications they will use. You might also consider a swag at peak operating times (evenings) and assume ~50% of the available students are online (simple queuing theory assumption). Then you could say that a single AP would cover minimally 20 students. There is my rule of thumb at this high level. I would consider it conservative if you design the network properly. In a typical dorm with a lot of walls (and bookcases...), you will probably find
RE: [WIRELESS-LAN] Wireless-only Dorms?
We have indeed reviewed both products. Currently we are a Meru user with nearly 150 AP's online. Since then we continue to monitor what similar technologies are emerging. In essence they are both similar, however there are key differences. The key differences are: The Extricom product doesn't operate at a full 100mW of power as most vendors, they run at 17dB according to their spec sheet. It also appears that the Extricom APs must connect directly to their switch and that they don't have seamless roaming from one switch to the next. *this is one where clarification is needed but based on their sheets and what I read from other sources* I am looking to find out if their switch operates as a centralized mac, it is a common solution for people trying to execute this architecture but would mean that all ap on a single switch would share bandwidth. We have been quite pleased with Meru from a user density and bandwidth perspective. Mike Mike Ruiz, ESSE ACP A+ Network and Systems Engineer Hobart and William Smith Colleges -Original Message- From: Jamie A. Stapleton [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 09, 2005 12:55 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Wireless-only Dorms? I believe that http://www.extricom.com/ does almost the same thing that Meru does. Has anyone compared/contrasted the two? Jamie A. Stapleton CBSi - Connecting your problems with solutions. FlexiCall: (804) 412-1601 Facsimile: (804) 412-1611 -Original Message- From: Michael Griego [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 09, 2005 12:47 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Wireless-only Dorms? All of the issues listed here are great examples of the complex nature of designing an 802.11 environment with such stringent requirements. With only 3 channels, even if you plan very carefully and precisely control the output power of your APs, you're going to get channel overlap. This will further reduce your capacity due to the inherent collisions/retransmissions. Especially when you factor in the client devices. A client device transmitting on a channel will force any other device operating on the same channel that can hear it (APs included if course) to wait on it to complete its transmission before it can commence. So, you have to realize that, even though 2 APs may not be able to hear each other, a client card between them that can hear both of them will tie up available bandwidth on BOTH APs while it is transmitting. Further complicating matters is a situation where two clients connected to two different APs on the same channel can hear each other but not both APs. In such a circumstance, client 1 and the AP 2 (the AP client 2 is connected) may transmit simultaneously. When this happens the signals will interfere with each other upon reaching client 2, causing client 2 to be unable to decode the packet, forcing AP 2 to retransmit the packet. Complicated indeed! Guaranteeing signal strengh and bandwidth alotments is extremely difficult. And, this totally ignores the problems inherent with outside interference or the fact that the environment (bookshelves, etc) change on a regular basis, possibly forcing you to revisit your ever-so-finely-tuned RF plan. Interestingly enough, all these issues are also extremely relevant if you're interested in looking to deploy any sort of VoIP/WiFi (VoFi). I'd suggest that, if you're truly interested in providing coverage/bandwidth that takes a lot of these issues into account, you might want to take a look at the Meru Virtual AP architecture. The controllers in these systems keep track of every 802.11 device each AP can here and employ a pretty darn impressive scheduling algorithm for getting the most out of the available channel capacity. Not only that, but they actually control when clients are allowed to transmit, further removing unknowns from the RF use equations and improving channel usage and capacity. I believe they do this using the PCF, or Point Coordination Function, in the 802.11 spec... I've not seen any other wireless switch system that makes use of it near to the level that the Meru system does. It's pretty cool. We're in the process of deploying Meru as our second generation wireless overlay here at UTD, mainly to decrease the need for complex channel planning, individual AP configuration, and to support a future VoFi implementation. --Mike Phil Raymond wrote: If someone forced me to assign a rule of thumb at this high level, I would assign a conservative data rate of 1 Mbps to each student as a requirement. For an 802.11g ONLY network running at the highest data rate (aka strongest signal) using enterprise class AP's (data thruput does vary between AP vendors, be careful here), you should expect to get 15-20 Mbps of upper layer thruput per AP. That would yield 15-20 students per AP. For 802.11a, this will probably hold.
