
Summit WM series switch, access points, and WLAN switch software and your network
Summit WM Series WLAN Switch and Altitude Access Point Software Version 4.1 User Guide
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In the Summit WM series switch, access points, and WLAN switch software system, network access
policy is carried out by means of packet filtering within a WM-AD.
In the Summit WM series switch user interface, you set up a packet filtering policy by defining a set of
hierarchical rules that allow or deny traffic to specific IP addresses, IP address ranges, or service ports.
The sequence and hierarchy of these filtering rules must be carefully designed based on your enterprise
user access plan.
The authentication technique selected determines how filtering is carried out:
● If authentication is by SSID and Captive Portal, a non-authenticated filter allows all users to get as
far as the Captive Portal Web page, where logon authentication occurs. When authentication is
returned, then filters are applied, based on user ID and permissions.
● If authentication is by AAA (802.1x), users have logged on and have been authenticated before being
assigned an IP address. When authentication is completed, the authenticated filter is assigned by
default unless a more user-specific filter is returned or indicated by the authentication mechanism.
The characteristics and level of access for a filter are controlled and defined by the system
administrator.
Mobility and roaming
In typical configurations that are not Summit WM series switches, APs are setup as bridges that bridge
wireless traffic to the local subnet. In bridging configurations, the user obtains an IP address from the
same subnet as the AP. If the user roams within APs on the same subnet, it is able to keep using the
same IP address. However, if the user roams to another AP outside of that subnet, its IP address is no
longer valid. The user's client device must recognize that the IP address it has is no longer valid and re-
negotiate a new one on the new subnet. The protocol does not mandate any action on the user. The
recovery procedure is entirely client dependent. Some clients automatically attempt to obtain a new
address on roam (which affects roaming latency), while others will hold on to their IP address. This loss
of IP address continuity seriously affects the client's experience in the network, because in some cases it
can take minutes for a new address to be negotiated.
The Summit WM series switch, access points, and WLAN switch software solution centralizes the user's
network point of presence, therefore abstracting and decoupling the user's IP address assignment from
that of the APs location subnet. That means that the user is able to roam across any AP without loosing
its own IP address, regardless of the subnet on which the serving APs are deployed.
In addition, a Summit WM series switch can learn about other Summit WM series switches on the
network and then exchange client session information. This enables a wireless device user to roam
seamlessly between different Altitude APs on different Summit WM series switches.
Network availability
Summit WM series switch, access points, and WLAN switch software provides availability against
Altitude AP outages, Summit WM series switch outages, and even network outages. The Summit WM
series switch (WM200/2000 model) in a VLAN bridged WM-AD can potentially allow the user to retain
the IP address in a failover scenario, if the WM-AD/VLAN is common to both controllers. For example,
availability is provided by defining a paired controller configuration by which each peer can act as the
backup controller for the other's APs. APs in one controller are allowed to failover and register with the
alternate controller.
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