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Performance: Wi-Fi connections on North Campus

Last Updated:
2012-09-13 00:00:00
Event:
2012-08-27 00:00:00
Status:
Closed
Brief Description:
Wi-Fi
User Impact:
N/A
Workaround:
There is no workaround for this issue
Current Status:
N/A
Services Affected:
Full Description:
Wi-Fi connectivity on North Campus is significantly improved, and most issues have been addressed at this point. CIT is continuing to closely track performance.



Timeline of Changes

Description Current Status Date Time
The Wi-Fi connectivity issues on North Campus have been resolved. The Wi-Fi connectivity issues on North Campus have been resolved. 2012-09-13 00:00:00
A key remaining piece in the Wi-Fi issue affecting North Campus has been addressed. CIT believes this may resolve the connectivity problem for most users. We will continue to closely track Wi-Fi performance over the weekend to verify.\n \nBelow is a technical recap since the issue was first reported:\n \n1. The RF output was moving up and down unexpectedly, which may have disconnected Wi-Fi users. Resolved 9/4/12.\n \n2. One reason for disconnects and low throughput was traced to how Macs running Mac OS 10.8 and 10.8.1 communicate their readiness status to wireless access points. Not resolved; it is hoped Apple will correct in a future OSX release.\n \n3. New code required by new FCC regulations was locking out A band access points for 60 seconds at a time. Resolved 9/6/12.\n \n4. A subtle interaction between our DHCP process and a reversed default setting in the new Aruba code installed this summer was causing users to lose their DHCP lease and get locked out of the system until they did a new ARP request, which in some computers has taken up to 30 minutes. Resolved 9/6/12.\n \n5. An issue with gateway addresses on the access point controllers was locking out whole vlans from connectivity. Resolved 9/7/12. A key remaining piece in the Wi-Fi issue affecting North Campus has been addressed. CIT believes this may resolve the connectivity problem for most users. We will continue to closely track Wi-Fi performance over the weekend to verify.\n \nBelow is a technical recap since the issue was first reported:\n \n1. The RF output was moving up and down unexpectedly, which may have disconnected Wi-Fi users. Resolved 9/4/12.\n \n2. One reason for disconnects and low throughput was traced to how Macs running Mac OS 10.8 and 10.8.1 communicate their readiness status to wireless access points. Not resolved; it is hoped Apple will correct in a future OSX release.\n \n3. New code required by new FCC regulations was locking out A band access points for 60 seconds at a time. Resolved 9/6/12.\n \n4. A subtle interaction between our DHCP process and a reversed default setting in the new Aruba code installed this summer was causing users to lose their DHCP lease and get locked out of the system until they did a new ARP request, which in some computers has taken up to 30 minutes. Resolved 9/6/12.\n \n5. An issue with gateway addresses on the access point controllers was locking out whole vlans from connectivity. Resolved 9/7/12. 2012-09-07 00:00:00
CIT is continuing to work with the Wi-Fi vendors to troubleshoot persistent issues with Wi-Fi connectivity on North Campus. Several factors are contributing. We have been tracking each factor and working closely with the vendors to apply recommended fixes. \n\nOne fix was applied shortly after noon to relieve a problem involving radar interference that was causing access points to shut down for 60-second periods. Another fix affecting IP leases was applied around 6 pm, which should improve performance for many users.\n \nWe are also continuing to investigate why Mac computers are disproportionately affected by connection issues. Our incomplete understanding at this point is that it is at least one issue with how Macs running Mac OS 10.8 and 10.8.1 communicate their readiness status to wireless access points. Because the Macs are not sending the communication that the access point expects, the two get out of sync, leading to connection problems and poor throughput. Our wireless vendor has communicated the issue back to Apple and hopefully a later OSX release will address the problem. In the meantime we continue to test and monitor the system for other issues. CIT is continuing to work with the Wi-Fi vendors to troubleshoot persistent issues with Wi-Fi connectivity on North Campus. Several factors are contributing. We have been tracking each factor and working closely with the vendors to apply recommended fixes. \n\nOne fix was applied shortly after noon to relieve a problem involving radar interference that was causing access points to shut down for 60-second periods. Another fix affecting IP leases was applied around 6 pm, which should improve performance for many users.\n \nWe are also continuing to investigate why Mac computers are disproportionately affected by connection issues. Our incomplete understanding at this point is that it is at least one issue with how Macs running Mac OS 10.8 and 10.8.1 communicate their readiness status to wireless access points. Because the Macs are not sending the communication that the access point expects, the two get out of sync, leading to connection problems and poor throughput. Our wireless vendor has communicated the issue back to Apple and hopefully a later OSX release will address the problem. In the meantime we continue to test and monitor the system for other issues. 2012-09-06 00:00:00
CIT strongly encourages Mac owners running OS X 10.8 (Mountain Lion) to use Software Update to bring their operating system up to date with the latest version, 10.8.1. While testing with this version, CIT technicians have not been able to reproduce the Wi-Fi connectivity issues being reported on North Campus, suggesting that the update may improve Wi-Fi performance in this situation.\n \nCIT is continuing to work with our Wi-Fi system vendor to investigate and resolve the issues with Wi-Fi on North Campus. Multiple factors appear to be contributing and are being examined. CIT strongly encourages Mac owners running OS X 10.8 (Mountain Lion) to use Software Update to bring their operating system up to date with the latest version, 10.8.1. While testing with this version, CIT technicians have not been able to reproduce the Wi-Fi connectivity issues being reported on North Campus, suggesting that the update may improve Wi-Fi performance in this situation.\n \nCIT is continuing to work with our Wi-Fi system vendor to investigate and resolve the issues with Wi-Fi on North Campus. Multiple factors appear to be contributing and are being examined. 2012-08-29 00:00:00
Two adjustments were made overnight to address some of the factors believed to be contributing to the issue. CIT is continuing to closely monitor W-Fi on North Campus and to troubleshoot possible causes of the connection problems. All controllers are functioning. Two adjustments were made overnight to address some of the factors believed to be contributing to the issue. CIT is continuing to closely monitor W-Fi on North Campus and to troubleshoot possible causes of the connection problems. All controllers are functioning. 2012-08-28 00:00:00
The problem seems isolated to North Campus. All controllers are up and functioning, with over 4,300 North Campus clients connected. Individuals reporting problems on North Campus are able to connect in other locations on campus. \n\nA disproportionate number of reports are coming from Mac users, so CIT is investigating a possible OS link. We have also escalated the incident to our WiFi system vendor and will be making some adjustments during the 5am-7am maintenance window. Another update will be posted after those changes. The problem seems isolated to North Campus. All controllers are up and functioning, with over 4,300 North Campus clients connected. Individuals reporting problems on North Campus are able to connect in other locations on campus. \n\nA disproportionate number of reports are coming from Mac users, so CIT is investigating a possible OS link. We have also escalated the incident to our WiFi system vendor and will be making some adjustments during the 5am-7am maintenance window. Another update will be posted after those changes. 2012-08-27 00:00:00