Wireless Access Point Features

Transcription

1 SPA Cmputers (P) Ltd. SPA cmputers (P) Ltd Phne: , 100feet Rad, Indira Nagar, Bangalre Fax Wireless Access Pint Features (IEEE a/b/g)

2 Feature 1 Wireless Access Pint Standard Article I. IEEE Overview Task Grups The task grups f the standard are: a - Created a standard fr WLAN peratins in the 5 GHz band, with data rates f up t 54 millin bits per sec (Mbps). Published in One f the cmpany using this standard is Athers ( b - Created a standard (als knwn as Wi-Fi) fr WLAN peratins in 2.4 GHz band, with data rates f up t 11 Mbps. Published in Prducts based n b include public space Internet kisks c - Prvided dcumentatin f specific MAC prcedures t the ISO/IEC (Internatinal Organizatin fr Standardizatin/Internatinal Electr Technical Cmmissin) (IEEE 802.1D) standard d - Publishing definitins and requirements t allw the standard t perate in cuntries nt currently served by the standard e - Attempting t enhance the MAC t increase the quality f service pssible. Imprvement in capabilities and efficiency are planned t allw applicatins such as vice, vide, r audi transprt ver wireless netwrks f - Develping recmmended practices fr implementing the cncepts f Access Pints and Distributin Systems. The purpse is t increase cmpatibility between Access Pint devices frm different vendrs g - Develping a higher-speed PHY extensin t the b standard, while maintaining backward cmpatibility with current b devices. The target data rate fr the prject is at least 20 Mbps h - Enhancing the MAC and a PHY t prvide netwrk management and cntrl extensins fr spectrum and transmit pwer management in the 5 GHz band. This is will allw regulatry acceptance f the standard in sme Eurpean cuntries i - Enhancing the security and authenticatin mechanisms f the standard. Onging.

3 Feature 2 Athers Bard Article II. Athers Chip Set Overview AR5312 System On Chip: Integrated MIPS 4000 Prcessr Supprts OFDM and CCK mdulatin Data rates f 1, 2, 5.5, 6, 9, 12, 18, 24, 36, 48, 54 Mbps and Athers Turb Mde ffering up t 108 Mbps Tw IEEE Ethernet MAC supprting 10/100 Mbps, full and half duplex, and MII interface t external Ethernet PHY UART with DMA supprts data rates up t 1 Mbps Flexible, prgrammable lcal bus EJTAG based debugging f the prcessr cre supprted AR 5112 & AR 2112 Radi On Chip (ROC) AR5112 supprts IEEE a/b/g standards Frequency fr IEEE a 4.9 GHz t 5.85 GHz and fr IEEE b/g 2.3 GHz t 2.5 GHz Mdulatin Technlgies OFDM with BPSK, QPSK, 16 QAM, 64 QAM DBPSK, DQPSK, CCK Hardware Encryptin WEP, AES, TKIP Quality f service 802.1e draft AR 2112 supprts IEEE b/g standards 2

4 Frequency fr IEEE b/g 2.3 GHz t 2.5 GHz Mdulatin Technlgies OFDM with BPSK, QPSK, 16 QAM, 64 QAM DBPSK, DQPSK, CCK Hardware Encryptin WEP, AES, TKIP Quality f service 802.1e draft System Blck Diagram 3

5 Feature 3 Sftw are Develped Article III. Driver Develpment Prting f AR5112 & AR2112 and IEEE MAC layer drivers frm VxWrks t Linux 2.4 Prting issues Changing all the system calls(api) frm VxWrks t Linux OS. Cnverting Virtual memry t physical memry s that Radi On Chip can make DMA transfer f descriptr queues fr transmissin. Since VxWrks desn t has virtual memry, in the given riginal VxWrks driver files its nt defined Fllwing diagram shws Driver layers Applicatins TCP/IP STACK MAC Layer( IEEE ) HAL Layer (Hardware Abstractin Layer) AR5112 & AR2112 Driver Hardware Initializatin f MAC layer Initializatin f Bard data which includes reading MAC address f the device frm EEPROM Initializatin f Driver data structure, Statin data structure, memry allcatin fr transmit and receive queues The Drivers data structure was initialized with cnfiguratin parameters read frm cnfiguratin text file The administratr f AP can mdify the cnfiguratin file with fllwing settings 4

6 AP IP address, enabling r disabling f WEP encryptin, cnfiguring pre-shared secret key fr encryptin, ptin fr 64 bit, 128bit, 154 bit keys, key type ex: hexadecimal r ASCII, cnfiguring SSID, beacn interval, cuntry cde, Wireless mde (ex a, b r g), data rate, SSID suppress enable/disable, fragmentatin threshld, sftware re-try enable/disable, WDS enable/disable, shrt preamble, RTS/CTS threshld. Initializatin f encryptin engines fr WEP, TKIP, AES Registering interrupts with Linux OS & task lets i.e. bttm half Registering the MAC layer with Linux OS as Netwrk Driver The MAC layer is registered with Linux OS The MAC layer is integrated with Linux TCP/IP stack The MAC layer uses Athers descriptr structure fr packet transmissin and receive but linux TCP/IP stack uses sk_buff structure. S there was need t cnvert Athers descriptr structure t sk_buff structure and vice versa. Driver features The ictl functinality has been added t change r mdify driver parameters Fr access cntrl MAC filtering has been added and administratr f AP can update the fllwing files with MAC address f the statins. MAC allw list MAC deny list Lg file functinality is prvided with fllwing 8 levels f messaging WLAN_LOG_EMERG ( High pririty ) WLAN_LOG_ALERT WLAN_LOG_CRIT WLAN_LOG_ERR WLAN_LOG_WARNING WLAN_LOG_NOTICE WLAN_LOG_INFO WLAN_LOG_DEBUG ( Lw pririty ) Linux prc files are updated with WLAN driver infrmatin 5

7 Feature 4 Sftw are Develped Article IV. Applicatin Develpment Applicatin mdule Blck diagram shw belw WNC Cnfiguratin Prgram: This mdule cnsists f the User Interface (UI ), Web server and CLI sub-mdules fr managing the Wireless Access Pint Set f APIs are prvided in t interact with HstApd mdule t prvide service t external request frm CLI( Telnet), Web UI etc CLI (Telnet), Web User Interface( UI) 6

8 HstApd bck diagram HstApd Cnfiguratin mdule HstAp Daemn mdule is respnsible fr managing the AP Web management, CLI and UI mdule interact with HstAp Daemn thrugh APIs fr varius services The hstapd scket API Lib will pen UDP scket fr inter-prcess cmmunicatin with HOSTAPD mdule. And HOSTAPD will cmmunicate with WLAN Driver mdule which is in the kernel space thrugh ictl t retrieve the data frm WLAN Driver. Hst API mdule develped These are set f APIs develped t enable varius mdules t interface with AP API mdule interacts with HstApd mdule t deliver requested service SNMPv2( RFC 2578) client develped MIB has different rt: is.member-bdy.us.ieee802dt11( ) 7

9 supprt fr fllwing MIB variables and MIB tables are prvided in the sftware dt11smt Cntains bjects related t statin management and lcal cnfiguratin dt11mac Cmpsed f bjects that reprt n the status f varius MAC parameters and allw cnfiguratin f them. dt11res Cntains bjects that describe available resurces dt11phy Reprt n the status f the varius physical layers SNMP Blck Diagram SNMP MANAGER Request SNMP Client Wireless Access Pint Running n LAN Respnse ictl API User Space Kernel Space Wlan Driver SNMP Client is implemented in the AP. The external SNMP Manager( Manager will be running n separate PC ver the netwrk ) sends requests t SNMP Client which is running n the Wireless Access Pint. The requests cmes frm Manager in the frm f ASN1(Abstract Syntax Ntatin One) ntatin. The SNMP Client parses the requests which is in the frm f ASN ntatin and retrieves the data frm wlan driver using Linux ictl API. After retrieving the data frm driver the SNMP Client again encdes the data in the frm f ASN ntatin and sends back the reply message t SNMP Manager. 8

10 RADIUS client develped (EAP ver RADIUS RFC 2869) Authenticatin types includes 802.1X and EAP prtcls RADIUS Authenticatin & Accunting Primary & Backup Servers Fail-ver limits, Re-attempt interval fr the primary server Authenticatin Exchange between mbile statin(supplicant), Authenticatr(AP) and Authenticatin Server (RADIUS) shw belw * Supplicant is statin( Mbile user), Authenticatr is Access pint, EAPOL ( Extensible Authenticatin prtcl ver LAN) 9