David T. Perkings Shi Yang IETF 70 th 2 Dec 2007, Vancouver CAPWAP WG MIB

 Problem Domain  Design Objectives  Design Idea  The MIBs Relationship  CAPWAP-MIB  CAPWAP-DOT11-MIB  An Example of MIB Usage  Current MIB Status Agenda

The IEEE standards have well-defined MIB for wireless binding technologies such as , Current centralized WLAN architectures of most vendors did not reuse IEEE MIB standards, while they define some private MIBs. It will make interoperability become impossible, the worse thing is IEEE and IETF standards are not able to work fine together. Problem Domain We require a way to avoid inventing new wheels.

 Work well under centralized architectures, and provides a way to centrally manage and control wireless network by SNMP  To reuse current MIB standards and future extension for a wireless binding technology  To enable interoperability between vendors Design Objectives

 The SNMP agent run on the AC side, through it, operators are able to manage and control WTP, radio such objects. The SNMP agent is not required at the WTP side.  Defines separated MIB files for CAPWAP protocol (CAPWAP-MIB) and its wireless binding (CAPWAP-Dot11 MIB). The CAPWAP-MIB should be Independent of any wireless binding technologies.  By “ Wireless Virtual Radio Interface ” abstract in the CAPWAP MIB, it enable MIB drafts to reuse IEEE MIB standards.  By “ WLAN Service Interface ” and “ WLAN BSS interface ” abstract in CAPWAP-DOT11-MIB, it provides a way to enable MAC mode and tunnel mode, also enable virtual AP. Design Idea

The MIBs Relationship CAPWAP-MIB CAPWAP-DOT11-MIB IF-MIB IEEE MIBs IETF MIB IEEE MIB ifIndex is bridge between above MIBs. It provides a way to reuse existing MIB and future extension, while keep them loose couple. Operators are able to manage centralized wireless architecture by these MIBs.

CAPWAP-MIB (1/2) The MIB function: - From AC to centrally manage and monitor WTPs; - As a generic mechanism, the MIB module is independent of any specific WTP radio technology; - The MIB module supports to query CAPWAP protocol parameters; - The MIB module supports to show WTPs current state; - The MIB module supports to configure “ WTP Virtual Radio Interface ” and PHY radio ’ s mapping relationship; - The counters are provided for WTP, radio's reboot event, hardware event failure and so on; - The MIB module provides the various notification like channel up,join failure and so on;

CAPWAP-MIB (2/2) Why “ WLAN Virtual Radio Interface ” is required? As centralized WLAN architecture, the administrator have to prepare configuration at AC side before WTPs connect to AC. For any wireless binding technology, the configuration and management of radio is very important. As usual, the standard of a binding technology provides MIB standard for radio management by itself. For example, according to IEEE MIB standards, the MIB tables such as Dot11OperationTable are able to support WTP radio configuration. These tables use ifIndex as index, and work well under standalone WLAN architecture. To reuse these MIB tables under centralized WLAN architecture, CAPWAP-MIB module brings forward a idea of "WTP Virtual Radio Interface". Administrator could create "WTP Virtual Radio Interface" at AC side, and it represents a specific PHY radio at WTP side by logical. With the ifIndex of a "WTP Virtual Radio Interface", administrator could configure WLAN radio parameter through IEEE MIB's tables such as Dot11OperationTable. As an Abstract interface, "WTP Virtual Radio Interface" could be used by any wireless binding technology such as IEEE and

CAPWAP-DOT11-MIB (1/2) The MIB function: - The MIB module supports to reuse current MIB standard and future extension of IEEE ; - The MIB module supports to configure MAC mode and tunnel mode for WLAN service; - The MIB module supports to keep PHY WTP and virtual AP mapping relationship;

CAPWAP-DOT11 MIB (2/2) Why “ WLAN Service Interface ” and “ WLAN BSS Interface ” is required? As centralized WLAN architecture, the administrator have to prepare configuration For each WLAN at AC side before WTPs connect to AC. According to IEEE MIB standards,the MIB tables such as Dot11AuthenticationAlgorithmsTable are able to support WLAN configuration, and these tables use ifIndex as index. To reuse these MIB tables under centralized WLAN architecture, CAPWAP-DOT11-MIB module brings forward a idea of "WLAN Service Interface". Administrator could create "WLAN Service Interface" at AC side, a specific ifIndex will corresponding to it. With the ifIndex, administrator could configure WLAN service's parameter through IEEE MIB's tables such as Dot11AuthenticationAlgorithmsTable. When administrator binds WLAN service to PHY radio through SNMP, WLAN system will dynamically create "WLAN BSS Interface", this logical interface will be used for data forwarding function.

An example of MIB Usage (1/4) 1) Create "WTP Virtual Radio Interface" to represent PHY radio on a WTP by CAPWAP-MIB In ifTable { ifIndex = 10, ifType = IANAifType of "WTP Virtual Radio Interface " ….. } 2) Configure IEEE wireless binding parameters for "WTP Virtual Radio Interface " by IEEE MIB. In Dot11OperationTable (As an example) { ifIndex = 10, dot11MACAddress = , dot11RTSThreshold = 2347, …. }

An example of MIB Usage (2/4) 3) Configure WLAN service A) Create a "WLAN Service Interface" through CAPWAP-DOT11-MIB. In CapwapDot11WLANConfigTable { capwapDot11WLANServiceIfIndex = 20, capwapDot11WLANId = 1, capwapWTPMACType = splitMAC(2), capwapWTPTunnelMode = dot3Tunnel, capwapDot11WLANConfigRowStatus = create } B) Configure WLAN parameters of "WLAN Service Interface"through IEEE MIB. In Dot11AuthenticationAlgorithmsTable (Example) { ifIndex = 20, dot11AuthenticationAlgorithmsIndex = 1, dot11AuthenticationAlgorithm = Shared Key, dot11AuthenticationAlgorithmsEnable = true }

An example of MIB Usage (3/4) 4) Bind "WTP Virtual Radio Interface" to radio Id by CAPWAP-MIB In CapwapRadioBindTable { capwapWTPId = capwapRadioId = 1 // Radio id capwapWTPVirtualRadioIfIndex = 10, // Virtual Radio Interface capwapWirelessBinding = dot11(2), capwapRadioBindRowStatus = create } 5) Bind WLAN service to WTP radio In CapwapDot11WLANBindTable { ifIndex = 10, // Virtual Radio Interface capwapDot11WLANServiceIfIndex = 20, // WLAN Service Interface capwapDot11WLANBSSIfIndex = 30, //WLAN BSS interface capwapDot11WLANBSSRowStatus = create }

An example of MIB Usage (4/4) 5) Operator query statistic data Operator could query statistic data of WTP, radio, station objects by IF-MIB, IEEE MIB (such as dot11CountersTable), CAPWAP-MIB and CAPWAP- DOT11-MIB (such as capwapWTPRebootStatsTable)

Current MIB Work Status The latest MIB drafts were published before IETF-70 th Meeting:  draft-ietf-capwap-base-mib-01  draft-ietf-capwap-802dot11-mib-01 At present, the framework of MIBs are stable. They provide MIB objects according to idea of above.

Questions? Comments?