RE: Density and Cisco LWAPP
Thanks to all who responded. We have taken the advice into great consideration and will deploy the APs in a manner that will incorporate the majority of the suggestions. For future reference to the vendors on the list: I know times are tough and everyone is trying to make a sale, but this was in no way a request for a competitive bid. Chip From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Greene, Chip Sent: Tuesday, February 17, 2009 10:23 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: [WIRELESS-LAN] Density and Cisco LWAPP We are currently looking to go totally wireless in two of our classrooms on campus. The rooms are back to back and we anticipate 90 users in each classroom, simultaneously. We are a totally Cisco shop and will not be using N for this deployment. The initial design plan calls for 5 APs in each classroom. 3APs will be A only and 2 will be G only. The G requirement is the only requirement we have for student laptops at this time. I am seeking feedback from anyone with experience in this type of deployment for large classrooms, specifically with Cisco products. Suggestions and recommendations would be appreciated. Thanks in advance. ___ Chip Greene Senior Network Specialist, CCSP Jepson Hall G-12 28 Westhampton Way Richmond, VA 23173 ** 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: Density and Cisco LWAPP
We have three SSIDs that we use here. From my limited testing the percentage drop in bandwidth utilization for management traffic happened after upping the beacon time interval. I did not try and set it back to the default to see if the utilization would correspondingly climb back up as yet. I'll be waiting till the summer break to do any more testing on it. We space our APs ~ 30' to 40' apart depending on the building and the population density. They are staggered per floor as best as possible. Brian Kellogg Network Services Manager St. Bonaventure University 716-375-4092 From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Greene, Chip Sent: Thursday, February 19, 2009 1:21 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: Density and Cisco LWAPP My assumption was that they were broadcasting a large number of SSIDs (up to 8) in a dense environment (possibly 5 -6 APs). At this level I would assume the beacon traffic and back-off algorithms may come into play. I will look into this either way. Brian, please correct me if my assumptions are incorrect. Chip From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Frank Bulk Sent: Wednesday, February 18, 2009 12:02 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Density and Cisco LWAPP Brian: Can you explain how the beacon period relates to management traffic dominating 802.11g traffic, besides the beacons that are (normally) sent every 100 msec? Frank From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Kellogg, Brian D. Sent: Tuesday, February 17, 2009 9:47 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Density and Cisco LWAPP We have a dense deployment of APs here. Typically we try to keep the number of users per AP to around a 1:9 ratio. What we found is that if you do not tweak the beacon period then the G spectrum ends up with around 20% of the available bandwidth being consumed by management traffic in a dense deployment. We have not had any adverse problems with changing this parameter, and I have not read anything as yet as to potential serious problems with modifying the default beacon period. Presently we have the beacon period set to one second and management traffic is consuming ~ 3% to 5% of the available bandwidth. We also disable multicast on our wireless networks which cuts down on certain unwanted multicast traffic from consuming bandwidth as well. We will most likely enable multicast in the future when we get time to determine what multicast we want to allow while blocking the rest. For example when we first set up our wireless network here we found that MS machines were sending out a lot of multicast traffic on 239.255.255.250 which is the SSDP Discovery service if I remember correctly. We used an ACL to block it from flooding our WLANs. Thank you, Brian Kellogg Network Services Manager St. Bonaventure University 716-375-4092 From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Greene, Chip Sent: Tuesday, February 17, 2009 10:23 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Density and Cisco LWAPP We are currently looking to go totally wireless in two of our classrooms on campus. The rooms are back to back and we anticipate 90 users in each classroom, simultaneously. We are a totally Cisco shop and will not be using N for this deployment. The initial design plan calls for 5 APs in each classroom. 3APs will be A only and 2 will be G only. The G requirement is the only requirement we have for student laptops at this time. I am seeking feedback from anyone with experience in this type of deployment for large classrooms, specifically with Cisco products. Suggestions and recommendations would be appreciated. Thanks in advance. ___ Chip Greene Senior Network Specialist, CCSP Jepson Hall G-12 28 Westhampton Way Richmond, VA 23173 ** 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/. ** 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/. ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
RE: Density and Cisco LWAPP
Brian: Can you explain how the beacon period relates to management traffic dominating 802.11g traffic, besides the beacons that are (normally) sent every 100 msec? Frank From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Kellogg, Brian D. Sent: Tuesday, February 17, 2009 9:47 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Density and Cisco LWAPP We have a dense deployment of APs here. Typically we try to keep the number of users per AP to around a 1:9 ratio. What we found is that if you do not tweak the beacon period then the G spectrum ends up with around 20% of the available bandwidth being consumed by management traffic in a dense deployment. We have not had any adverse problems with changing this parameter, and I have not read anything as yet as to potential serious problems with modifying the default beacon period. Presently we have the beacon period set to one second and management traffic is consuming ~ 3% to 5% of the available bandwidth. We also disable multicast on our wireless networks which cuts down on certain unwanted multicast traffic from consuming bandwidth as well. We will most likely enable multicast in the future when we get time to determine what multicast we want to allow while blocking the rest. For example when we first set up our wireless network here we found that MS machines were sending out a lot of multicast traffic on 239.255.255.250 which is the SSDP Discovery service if I remember correctly. We used an ACL to block it from flooding our WLANs. Thank you, Brian Kellogg Network Services Manager St. Bonaventure University 716-375-4092 From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Greene, Chip Sent: Tuesday, February 17, 2009 10:23 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Density and Cisco LWAPP We are currently looking to go totally wireless in two of our classrooms on campus. The rooms are back to back and we anticipate 90 users in each classroom, simultaneously. We are a totally Cisco shop and will not be using N for this deployment. The initial design plan calls for 5 APs in each classroom. 3APs will be A only and 2 will be G only. The G requirement is the only requirement we have for student laptops at this time. I am seeking feedback from anyone with experience in this type of deployment for large classrooms, specifically with Cisco products. Suggestions and recommendations would be appreciated. Thanks in advance. ___ Chip Greene Senior Network Specialist, CCSP Jepson Hall G-12 28 Westhampton Way Richmond, VA 23173 ** 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/. ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
RE: Density and Cisco LWAPP
When you have a dozen or more APs sending beacons every 100ms and they can all hear each other that drives up the usage is my guess. I was seeing in our more dense areas around 10% to18% bandwidth usage do to this traffic, and when I increased the beacon rate to one per second this usage dropped to 3% to 5%. I've not had time to investigate this as thoroughly as I'd like so please correct me if I am missing something. Thank you, Brian Kellogg Network Services Manager St. Bonaventure University 716-375-4092 From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Frank Bulk Sent: Wednesday, February 18, 2009 12:02 PM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: Density and Cisco LWAPP Brian: Can you explain how the beacon period relates to management traffic dominating 802.11g traffic, besides the beacons that are (normally) sent every 100 msec? Frank From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Kellogg, Brian D. Sent: Tuesday, February 17, 2009 9:47 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Density and Cisco LWAPP We have a dense deployment of APs here. Typically we try to keep the number of users per AP to around a 1:9 ratio. What we found is that if you do not tweak the beacon period then the G spectrum ends up with around 20% of the available bandwidth being consumed by management traffic in a dense deployment. We have not had any adverse problems with changing this parameter, and I have not read anything as yet as to potential serious problems with modifying the default beacon period. Presently we have the beacon period set to one second and management traffic is consuming ~ 3% to 5% of the available bandwidth. We also disable multicast on our wireless networks which cuts down on certain unwanted multicast traffic from consuming bandwidth as well. We will most likely enable multicast in the future when we get time to determine what multicast we want to allow while blocking the rest. For example when we first set up our wireless network here we found that MS machines were sending out a lot of multicast traffic on 239.255.255.250 which is the SSDP Discovery service if I remember correctly. We used an ACL to block it from flooding our WLANs. Thank you, Brian Kellogg Network Services Manager St. Bonaventure University 716-375-4092 From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Greene, Chip Sent: Tuesday, February 17, 2009 10:23 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Density and Cisco LWAPP We are currently looking to go totally wireless in two of our classrooms on campus. The rooms are back to back and we anticipate 90 users in each classroom, simultaneously. We are a totally Cisco shop and will not be using N for this deployment. The initial design plan calls for 5 APs in each classroom. 3APs will be A only and 2 will be G only. The G requirement is the only requirement we have for student laptops at this time. I am seeking feedback from anyone with experience in this type of deployment for large classrooms, specifically with Cisco products. Suggestions and recommendations would be appreciated. Thanks in advance. ___ Chip Greene Senior Network Specialist, CCSP Jepson Hall G-12 28 Westhampton Way Richmond, VA 23173 ** 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/. ** 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: Density and Cisco LWAPP
We have a dense deployment of APs here. Typically we try to keep the number of users per AP to around a 1:9 ratio. What we found is that if you do not tweak the beacon period then the G spectrum ends up with around 20% of the available bandwidth being consumed by management traffic in a dense deployment. We have not had any adverse problems with changing this parameter, and I have not read anything as yet as to potential serious problems with modifying the default beacon period. Presently we have the beacon period set to one second and management traffic is consuming ~ 3% to 5% of the available bandwidth. We also disable multicast on our wireless networks which cuts down on certain unwanted multicast traffic from consuming bandwidth as well. We will most likely enable multicast in the future when we get time to determine what multicast we want to allow while blocking the rest. For example when we first set up our wireless network here we found that MS machines were sending out a lot of multicast traffic on 239.255.255.250 which is the SSDP Discovery service if I remember correctly. We used an ACL to block it from flooding our WLANs. Thank you, Brian Kellogg Network Services Manager St. Bonaventure University 716-375-4092 From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Greene, Chip Sent: Tuesday, February 17, 2009 10:23 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Density and Cisco LWAPP We are currently looking to go totally wireless in two of our classrooms on campus. The rooms are back to back and we anticipate 90 users in each classroom, simultaneously. We are a totally Cisco shop and will not be using N for this deployment. The initial design plan calls for 5 APs in each classroom. 3APs will be A only and 2 will be G only. The G requirement is the only requirement we have for student laptops at this time. I am seeking feedback from anyone with experience in this type of deployment for large classrooms, specifically with Cisco products. Suggestions and recommendations would be appreciated. Thanks in advance. ___ Chip Greene Senior Network Specialist, CCSP Jepson Hall G-12 28 Westhampton Way Richmond, VA 23173 ** 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: Density and Cisco LWAPP
Thank you. I hadn't considered the beacon interval in too much detail. I will make sure I add this into the calculations. We also block multicast at this time as well. Chip From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Kellogg, Brian D. Sent: Tuesday, February 17, 2009 10:47 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Re: [WIRELESS-LAN] Density and Cisco LWAPP We have a dense deployment of APs here. Typically we try to keep the number of users per AP to around a 1:9 ratio. What we found is that if you do not tweak the beacon period then the G spectrum ends up with around 20% of the available bandwidth being consumed by management traffic in a dense deployment. We have not had any adverse problems with changing this parameter, and I have not read anything as yet as to potential serious problems with modifying the default beacon period. Presently we have the beacon period set to one second and management traffic is consuming ~ 3% to 5% of the available bandwidth. We also disable multicast on our wireless networks which cuts down on certain unwanted multicast traffic from consuming bandwidth as well. We will most likely enable multicast in the future when we get time to determine what multicast we want to allow while blocking the rest. For example when we first set up our wireless network here we found that MS machines were sending out a lot of multicast traffic on 239.255.255.250 which is the SSDP Discovery service if I remember correctly. We used an ACL to block it from flooding our WLANs. Thank you, Brian Kellogg Network Services Manager St. Bonaventure University 716-375-4092 From: The EDUCAUSE Wireless Issues Constituent Group Listserv [mailto:wireless-...@listserv.educause.edu] On Behalf Of Greene, Chip Sent: Tuesday, February 17, 2009 10:23 AM To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU Subject: Density and Cisco LWAPP We are currently looking to go totally wireless in two of our classrooms on campus. The rooms are back to back and we anticipate 90 users in each classroom, simultaneously. We are a totally Cisco shop and will not be using N for this deployment. The initial design plan calls for 5 APs in each classroom. 3APs will be A only and 2 will be G only. The G requirement is the only requirement we have for student laptops at this time. I am seeking feedback from anyone with experience in this type of deployment for large classrooms, specifically with Cisco products. Suggestions and recommendations would be appreciated. Thanks in advance. ___ Chip Greene Senior Network Specialist, CCSP Jepson Hall G-12 28 Westhampton Way Richmond, VA 23173 ** 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/. ** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/groups/.
