Configuring wlan roaming, Wlan roaming overview, Terminology – H3C Technologies H3C WX3000E Series Wireless Switches User Manual
Page 97: Wlan roaming topologies
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Configuring WLAN roaming
WLAN roaming overview
Inter AC Tunneling Protocol (IACTP) is a proprietary protocol of H3C which defines how access
controllers (ACs) communicate with each other. Based on the standard TCP client/server model, this
protocol generically encapsulates and transports communications securely between ACs.
You can use IACTP to create and maintain AC groups, termed mobility groups, which can include up to
8 ACs. IACTP provides a secure control tunnel for applications such as roaming that allow sharing and
exchanging messages. IACTP can be used with either IPv4 or with IPv6.
When a station first associates with an AC in a mobility group, that AC becomes the station's Home-AC
(HA). The connection request goes through 802.1X authentication followed by 11 Key exchange, and the
station information is then synchronized across the other ACs in the mobility group.
When the station roams to another AC in the mobility group (a Foreign-AC (FA)), the HA information is
used to fast-forward station authentication by skipping 802.1X authentication and performing only
802.11 key exchange. This method facilitates seamless roaming within a mobility group.
Terminology
•
HA—The AC to which a wireless station is connected by associating with an AP for the first time is
the HA of the station.
•
FA—An AC that is other than the HA and to which a station is currently connected is an FA of the
station.
•
Fast-roam capable station—A wireless station that associates to an AC in the mobility-group and
supports fast roaming (only key caching is supported).
•
Roam-out station—A wireless station that has associated with an AC other than the HA in the
mobility-group is a roam-out station at its HA.
•
Roam-in station—A wireless station that has associated with an AC other than the HA in the
mobility-group is a roam-in station at the FA.
•
Intra-AC roaming—A procedure where a wireless station roams from one AP to another AP, which
are connected to the same AC.
•
Inter-AC roaming—A procedure where a wireless station roams from one AP to another AP, which
are connected to different ACs.
•
Inter-AC fast roaming capability—If a station uses 802.1X (RSN) authentication through negotiation
and supports key caching, this station has inter-AC fast roaming capability.
WLAN roaming topologies
WLAN Roaming topologies consist of:
•
Intra-AC roaming topology
•
Inter-AC roaming topology
•
Intra-FA roaming topology
- H3C WX5500E Series Access Controllers H3C WX3500E Series Access Controllers H3C WX2500E Series Access Controllers H3C WX6000 Series Access Controllers H3C WX5000 Series Access Controllers H3C WX3000 Series Unified Switches H3C LSWM1WCM10 Access Controller Module H3C LSUM3WCMD0 Access Controller Module H3C LSUM1WCME0 Access Controller Module H3C LSWM1WCM20 Access Controller Module H3C LSQM1WCMB0 Access Controller Module H3C LSRM1WCM2A1 Access Controller Module H3C LSBM1WCM2A0 Access Controller Module H3C WA3600 Series Access Points H3C WA2600 Series WLAN Access Points