Shi Yang David T. Perkins IETF 70th 3 Dec 2007, Vancouver CAPWAP Protocol and Dot11 Binding MIB Shi Yang David T. Perkins IETF 70th 3 Dec 2007, Vancouver

} Agenda Problem Domain Design Objectives Basic Idea CAPWAP-MIB CAPWAP-DOT11-MIB An Example of MIB Usage Current MIB Work Status Next Step General information for MIB design

Problem Domain The IEEE standards have well-defined MIB for wireless binding technologies such as 802.11, 802.16. Current centralized wireless architectures of most vendors do not reuse IEEE MIB standards, while they define some private MIBs. It will make interoperability impossible; IEEE and IETF WLAN MIBs will be unable to work well together . We require a way to avoid reinventing the wheel for Centralized Wireless Architecture.

Design Objectives for MIB To work well under centralized architectures, and provide a way to centrally manage and control wireless network by SNMP To be consistent with CAPWAP protocol To reuse current MIB standards and future extensions for a wireless binding technology To enable interoperability between vendors To meet operator requirements for centralized architectures Reuse 802.11 802.11a/b/g 802.11e 802.11i 802.11k IEEE WG MIB standards

Basic Idea (1/3) The SNMP agent run on the AC side, and it MAY not be required on the WTP side MIB files defined separately 1) CAPWAP protocols (CAPWAP-MIB) 2)Wireless binding (CAPWAP-Dot11 MIB) The CAPWAP-MIB is independent of any wireless binding technologies The MIB design follows same idea as CAPWAP: Centralized Control CAPWAP WTP Operator AC SNMP SNMP Agent WTP WTP

Basic Idea (2/3) To decide on the configured and monitored MIB objects is NOT very difficult, as CAPWAP protocol already defines them well To be independent of any wireless binding technologies and Have ability to reuse MIB standards of other SDOs, is the Main Challenge for design of the CAPWAP MIB The ifIndex (RFC1213) will play a role in bridging between MIB standards defined by different SDOs 6

Other Wireless Binding Basic Idea (3/3) The operator could manage and control the centralized wireless architectures using multiple MIB standards defined by multiple SDOs, while keeping them loosely coupled. Operator Agent SNMP IETF Organization IEEE 802.11 WG Other Wireless Binding CAPWAP-DOT11-MIB IEEE MIB IEEE 802.16 RFID CAPWAP-MIB IF-MIB

CAPWAP-MIB MIB function Background Information Basic Idea WTP Virtual Radio Interface 8

Function CAPWAP-MIB function: - From AC to centrally managed and monitored WTPs - As a generic mechanism, the MIB module is independent of any specific wireless binding technologies - The MIB module supports CAPWAP protocol parameters queries - The MIB module supports showing the WTPs’ current state - The MIB module supports indicating the “WTP Virtual Radio Interface” and PHY radio’s mapping relationship - Counters are provided for WTP, radio's reboot event, hardware failure etc. - The MIB module provides the various notification like channel-up, join failure, etc.

Background Information (1/2) As centralized Wireless architecture, the operator has to prepare configuration at AC side before WTPs connects to AC. For any wireless binding technology, the configuration and management of radio is very important. Under centralized Wireless architecture WTP Id Identified by PHY Radio + Radio Id

Background Information (2/2) As usual, the standard of a binding technology provides MIB standard for radio management on its own. For example, according to IEEE 802.11 WG MIB standards, the MIB tables such as Dot11OperationTable are able to support WTP radio configuration. These tables use ifIndex as the index, and work well under standalone Wireless architecture IEEE 802.11 WG MIB Identified by PHY Radio ifIndex

+ Basic Idea To reuse MIB objects (defined by SDOs such as IEEE) for radio is very import To reuse IEEE 802.11 WG and other WG’s MIB standards, the key point is to reuse the idea of ifIndex To have a way to maintain the mapping relationship between “WTP id+ radio id” and “ifIndex” PHY Radio CAPWAP IEEE 802.11 WG MIB Identified by Identified by WTP Id ifIndex + How to map to each other? Radio Id 12

WTP Virtual Radio Interface (1/2) IfIndex can identify an interface in abstract way, and it does NOT care for an interface’s PHY location (WTP or AC) AC can have interfaces of “WTP Virtual Radio Interface” ifType, it will logically represents PHY radios on the WTPs side It looks like that PHY radios are located on the AC side Operator can operate radios by MIB tables (such as IEEE 802.11 WG’s) with ifIndex of “WTP Virtual Radio Interface” as Index AC WTP Operator WTP Virtual Radio Interface 1 PHY Radio 1 SNMP CAPWAP WTP Virtual Radio Interface 2 PHY Radio 2 WTP Virtual Radio Interface n PHY Radio n 13

WTP Virtual Radio Interface (2/2) As an Abstract interface, "WTP Virtual Radio Interface" could be used by any wireless binding technology such as IEEE 802.11 and 802.16 The table of capwapRadioBindTable will indicate the mapping relationship between “WTP id + Radio id” and IfIndex PHY Radio IEEE 802.11 WG MIB (or any wireless binding) CAPWAP WTP Id ifIndex INDEX { capwapWTPId, capwapRadioId } + Radio Id

CAPWAP-DOT11-MIB MIB function Background Information WTP Virtual Radio Interface Virtual AP 15

Function CAPWAP-DOT11-MIB Function: The MIB module supports the reuse of current IEEE 802.11 WG MIB standards and future extensions The MIB module supports the configuration of the MAC mode and tunnel mode for Wireless service The MIB module supports virtual AP

Background Information (1/2) As centralized Wireless architecture, the operator has to prepare configurations for each wireless at AC side before WTPs are able to connect to AC Under centralized Wireless architectures: Identified by Wireless Service Wireless Id Operator could configure MAC type or tunnel mode for a Wireless service

Background Information (2/2) IEEE 802.11 WG MIB does not suggest how to support virtual AP According to IEEE 802.11 MIB standards, the MIB tables such as Dot11AuthenticationAlgorithmsTable are able to support Wireless configuration (such as authentication algorithm), and these tables use ifIndex as index IEEE 802.11 WG MIB Identified by Wireless Service ifIndex

Wireless Service Interface A Wireless service could be abstracted as an Interface, and which could be identified by ifIndex. On the AC side, the MIB table CapwapDot11WirelessConfigTable will indicate the mapping relation between “A Wireless ID” and ifIndex of a “Wireless Service Interface” Wireless ID 2 Wireless ID Wireless ID 3 Wireless Service Interface With ifIndex of it to reuse IEEE MIBs 19

Wireless BSS Interface Virtual AP By the table of capwapDot11WirelessBindTable, the operator are able to bind Wireless service to a specific radio through SNMP Wireless system will dynamically create the "Wireless BSS Interface“ BSS interface will be used for the data forwarding function Radio bind Wireless ID Dynamically Create Wireless BSS Interface Identified by ifIndex 20

Summary CAPWAP-MIB focus in how to manage and control WTP, and how to support any wireless binding through the mechanism of “WTP Virtual Radio Interface” CAPWAP-DOT11-MIB focus in how to support configuration of MAC type and tunnel mode for WLAN service, and how to support Virtual AP. With “WLAN Service Interface”, it is able to Reuse IEEE 802.11 MIB. Wireless binding related MIB objects will be defined by IEEE such kinds SDOs IF-MIB could be used to model interface (such as WLAN Service interface) 21

An example of MIB Usage (1/4) 1) The mapping relationship between “WTP Virtual Radio Interface” and “WTP Id + Radio id” (CAPWAP-MIB) When configuration for a WTP is prepared before it connects to AC, the following information is available in the CapwapRadioBindTable Identify a WTP In CapwapRadioBindTable { capwapWTPId = 12345678 capwapRadioId = 1 capwapWTPVirtualRadioifIndex = 10 capwapWirelessBinding = dot11(2) } Identify a radio ifIndex of a “WTP Virtual Radio Interface” The type of ”Wireless Binding”

An example of MIB Usage (1/5) 2) Operator configure Wireless radio through IEEE MIB In Dot11OperationTable (Example) { ifIndex = 10, dot11RTSThreshold = 2347, dot11ShortRetryLimit = 7, dot11LongRetryLimit = 4, dot11FragmentationThreshold = 256, dot11MaxTransmitMSDULifetime = 512 ……. } ifIndex of a “WTP Virtual Radio Interface” Wireless Radio Parameter

An example of MIB Usage (2/5) 3) Configure wireless service A) Create a "Wireless Service Interface" through CAPWAP-DOT11-MIB. In CapwapDot11WirelessConfigTable { capwapDot11WirelessId = 1, capwapDot11WirelessServiceIfIndex = 20, capwapWTPMACType = splitMAC(2), capwapWTPTunnelMode = dot3Tunnel, capwapDot11WirelessConfigRowStatus = create } Wireless ID ifIndex of “Wireless Service Interface” MAC Type and Tunnel Mode

An example of MIB Usage (3/5) B) Configure Wireless parameters of "Wireless Service Interface" through IEEE 802.11 MIB. In Dot11AuthenticationAlgorithmsTable (Example) { ifIndex = 20, dot11AuthenticationAlgorithmsIndex = 1, dot11AuthenticationAlgorithm = Shared Key, dot11AuthenticationAlgorithmsEnable = true } ifIndex of “Wireless Service Interface” Wireless Authentication Parameter 25

An example of MIB Usage (4/5) 4) Bind Wireless service to WTP radio In CapwapDot11WirelessBindTable { ifIndex = 10, capwapDot11WirelessId = 1, capwapDot11WirelessBSSIfIndex = 30, capwapDot11WirelessBSSRowStatus = create } ifIndex of “WTP Virtual Radio Interface” Wireless Id ifIndex of “Wireless BSS Interface”

An example of MIB Usage (5/5) 5) Operator query the statistic data Operator could query statistic data of WTP, radio, station objects by IF-MIB, IEEE 802.11 MIB (such as dot11CountersTable), CAPWAP-MIB and CAPWAP-DOT11-MIB (such as capwapWTPRebootStatsTable) Counters refer to CAPWAP Protocol

Current MIB Work Status The first version(00) of CAPWAP-MIB and CAPWAP-DOT11-MIB were published in July 2007. http://tools.ietf.org/id/draft-yangshi-capwap-802dot11-mib-00.txt http://tools.ietf.org/id/draft-yangshi-capwap-base-mib-00.txt The latest MIB drafts (version 01) are planed to be published after IETF-70th Meeting. The co-editor of drafts are Shi Yang and David T. Perkins Request More Comments from CAPWAP WG

Next Step Request CAPWAP-MIB and CAPWAP-DOT11-MIB to be CAPWAP WG’s Formal Drafts. 29

Questions? Comments?