User complaints when the WiFi certification system is online"Walking around the net is off."A user moves from one AP to another, and a mobile phone switching to the AP triggers a short break in network or even requires re-entry of an account number password. Is it not about AC? What does the authentication system have to do with it? It is important because the AAP switch session can be continued when the authentication status is tied to the AC session sheet, determining whether the user has no sense or the network.
Basic process of roaming
Wireless terminals, while moving, when the current connection of AP signals is detected to be weak and there are stronger AP signals nearby, voluntarily disconnect the current AP connections and switch to a more powerful AP. This transition process is called roaming. The terminal needs to reconnect with the new AP when switching to complete 802.1X authentications, and if it is Portal authentication, it will need to re-enact the EAP certification process; depending on whether AC synchronizes the user ' s authentication session from old AP to new APs.
The difference between two and three layers of roaming
Two layers of roaming are the switch between APs in the same VLAN, IP addresses remain unchanged, ACs simply move sessional items from old to new APs and authentication status can be continued without user feeling. Three levels of roaming is the switch between users to different VLAN APs when IP addresses may change and authentication sessions need to be re-established. When a company deploys, it reduces three layers of travel by allowing the same type of user ' s APs to be located within the same VLAN. Each layer of APs is placed on different VLANs, which triggers three layers of drifting down the floor, with poor experience. The correct approach is to assign VLAN to the user type, not VLAN to the floor, and SSID to all floors of staff VLAN.
Portal certified roaming session maintained
Portal authenticated user information is available in the AC session, including IPs, MACs, authentication status, online time, quotas, etc.. When AP switching, if AC supports the meeting keeping, old AP session items will be synchronized to new AP and users do not need to re-authenticate it. Not all ACs support Portal session maintenance, some ACs remove older sessions from AP switching, and users have to re-check Portal certification.
802.1X certified quick roaming
802.1X certification of complete EAP processes takes hundreds of milliseconds to one second, and the user who walks through it every time is obviously feeling out of the net. The fast-walking mechanism (OKC and PMKID cache) allows a terminal to skip full EAP authentication when switching to previously associated APs, directly connecting with a cache key, and travel time down to dozens of milliseconds. But OKC requires end and AC support, apple support is good, some Andre support is incomplete."Support for fast roaming"Just think it's okay.
MAC unconscious and wandering.
When the MAC is unsophisticated, the user has successfully validated the first Portal authentication, recording the MAC address in the system and automatically authenticating release on subsequent connections. APP switch during a cruise, when the MAC clears the session, automatically re-authentication will occur without the user having to enter the account number password, but there is still a delay in recertification, usually within one second. The MAC unconscious validity period needs to be set properly, too short for users to re-validate each day, and the equipment of an ex-staff member can be automatically connected if it is too long.
A. Special problems of cross-AC cruises
ACs are mobile between different AC-covered areas of large enterprises. Trans-ACs travel requires that they support the cruise protocol (e.g., IRF for H3Cs and a Chinese roaming group) and authentication sessions synchronize with ACs. If an AC does not support cross-ACs, users must recertification when switching to ACs. V7 systems can kick off their user lines to trigger recertification, but this is not a normal process. Trans-AC roaming capability is considered at the design stage, while the size of the roaming groups is confirmed by the AC selection, rather than waiting for it to be discovered after the upper line before trans-AC will be able to find out how to re-validate.
The idea of a line to swim across the line.
Users complain about the drifting down line, first checking whether AC log: AP switch triggers recertification, Radius receives new authentication requests, certification results are successful or failed. If Radius receives a request but returns to fail, check if the user account status is expired and the number of distributions are exceeded. If AC does not trigger re-certification but the user breaks off the network, the signal strength at the time of the AAP switch may be the blind area with AP cover, and the terminal rotates between two APs (the Ping-Ping effect). The ping-pong effect will have to adjust the AP power or channel so that AP covers the boundary without overlap.
Practical measures to optimize roaming
First, the signal overlap area is controlled at 15-20% of AP deployments, too many overlapping easy ping-pong and too few overlapping blind areas. Second, ACs are open to fast roaming (OKC) and Portal sessions. Third, VLANs are selected by user type to avoid three layers of travel. Fourth, MAC has no perceived validity for 7-30 days, balancing security and experience. Fifth, high-intensity regions (conference rooms, canteens) use high-secret APs to adjust end-runting thresholds to allow terminals to switch earlier to better signals. Sixth, regular signal heat attempts with survey tools to detect timely completion of blind areas.
The WiFi certification system of enterprises does not have a roaming experience that can be determined by the authentication system alone, but is related to AC capabilities, AP deployment, VLAN planning, and terminal compatibility. Program phase confirms AC Portal chat maintenance and 802.1X fast-walking capability, deployment phase VLAN reduces three layers of roaming by user type, and wiring rate monitoring and optimizes AP coverage during the wiring phase, which achieves three steps where users do not feel network disruptions while moving around the office area.