Protocol Processing on the FPX

Transcription

1 Field-programmable Port Extender (FPX) January 2002 Workshop Protocol Processing on the FPX John Lockwood, Assistant Professor Washington University Department of Computer Science Applied Research Lab 1BrookingsDrive Saint Louis, MO Copyright Supported by: NSF ANI and Xilinx Corp. FPX Network Platform 1 Typical Network Protocol Stack Existing Network Applications Existing IP Applications Vat/NV Mosaic Native-Mode Applications User Layer Other Ethernet or Token Ring based LAN Protocols UDP IP -or- TCP Network Layer LAN Emulation LANE Adaptation Layer (Segmentation/Reassembly) AAL5 AAL3/4 AAL0 (null) Endpoint Functions Virtual Circuit Services Cells Cell Functions Physical Transmission SONET TAXI T3/T1 Copper Telcom/Datacom Services FPX Network Platform 2

2 ATM Cell Format Header [5 bytes in 2 words] Payload [48 bytes in 12 words] VPI VCI HEC P0 PT PAD P1 P2 P3 P4 P5 P6 P7 P8 P9 P10 P11.. Payload.. P44 P45 P46 P47 32 bits Header VPI: Virtual Path Identifier 12 bits [31 downto 20] of Word 0 VCI: Virtual Circuit Identifier 16 bits [19 downto 4] of Word 0 PT: Payload Type 4 bits [3 downto 0] of Word 0 HEC: Header Error Check 8 bits [31 downto 24] of Word 1 PAD: Padding 24 bits [23 downto 0] of Word 1 Payload P0..P47 FPX Network Platform 3 Adaptation Layer Five: AAL5 ATM Cell Header Payload Individual Cells AAL5 Frame Frame CRC Check (4 bytes) Frame Length (2 bytes) CPCS-UU and CPI fields (2 bytes) Pad (0-47 bytes) User Data / Encapsulated Protocol Provides Variable-sized Packet Delivery Performs CRC Frame Error Checking FPX Network Platform 4

3 Network Packet Format Cell Header Payload[0] 0 IP Packets segmented in cells IP Packet 0 Payload[1] 1 Payload[2] Padding AAL5 Trailer Traffic flows assigned to VCI LastCellindication options CRC-32 length FPX Network Platform 5 Protocol Headers Cell Header IP Header UDP IP Header Payload PAD AAL5 Trailer AAL5 Pad CPS-UU & CPI Frame Len AAL5 Frame Checkum AAL5 FPX Network Platform 6

4 The Layered Protocol Wrapper Library Circuits that streamline functions to process cells, frames, IP packets, and UDP datagrams in reprogrammable hardware A layered design that consists of different processing circuit in each layer Allows application to be implemented at a level where important details are exposed and irrelevant details are hidden FPX Network Platform 7 Basic Concept of the Protocol Wrappers Application Wrapper Wrapper FPX Network Platform 8

5 Layered Protocol Wrappers Interfaces to Off-Chip Memories Application-level Hardware Module Data Input Data Output UDP Processor IP Processor Frame Processor Cell Processor FPX Network Platform 9 Overview of the Protocol Wrappers The Protocol Wrappers is composed of: Cell Processor Receives and sends ATM cells Frame Processor Receives and sends variable length AAL5 frames IP Processor Receives and sends Internet Protocol packets UDP Processor Receives and sends User Datagram Protcol messages FPX Network Platform 10

6 Building an UDP Application Application reads inputs from the UDP Wrapper Input Signals D_MOD_IN (data input) DataEn_MOD_IN (data enable) SOF_MOD_IN (start of frame) SOD_MOD_IN (start of datagram) EOF_MOD_IN (end of frame) TCA_MOD_IN (congestion control) FPX Network Platform 11 Building an UDP Application (More) Similarly, Application writes output to the UDP Wrapper Output Signals D_OUT_MOD (data output) DataEn_OUT_MOD (data enable) SOF_OUT_MOD (start of frame) SOD_OUT_MOD (start of datagram) EOF_OUT_MOD (end of frame) TCA_OUT_MOD (congestion control) FPX Network Platform 12

7 Protocol Wrapper Signal Notes Obey the protocol wrapper control signals Use the Frame and data signals StartofFrame(SOF):May repeat for aborted packets StartofData(SOD):Active high on first word of UDP End of Frame (EOF) : Active high on last word UseData Enable (DataEn) signal Active high during valid data Note that DataEn can immediately follow SOF FPX Network Platform 13 Building an UDP Application (More) Other important input signals CLK Clock signal for module 100 MHz Reset_l Synchronous reset Low for 1 clock cycle to reset state machines Set by reconfiguration logic FPX Network Platform 14

8 Protocol Wrappers Waveforms CLK Data SOC Data DataEn SOF A A I I I I I U U D D D D D - - A A D D D D D D D P P P F F - - A - I I I I I U U D D D D D D D D D D D D F F Cell Level Frame Level IP Level EOF SOP/ SOD Only use these signals to process UDP/IP packets A ATMHeader - Don't care This cycle is optional. It does not appear in simulation I U IPHeader UDP Header D Payload Data P Padding UDP payload starts 2 cycles after SOP signal. F Frame Trailer Data Enabled during frame trailer UDP payload ends with EOF signal. FPX Network Platform 15 UDP/IP Packet Fields Word # Payload AAL5 Trailer At end of packet N-1 N Cell Header Ver HL ToS Packet Len IPID Fragment TTL Proto Checksum Source IP address Destination IP address Src Port Length Dest Port Checksum H e l l o CPS-UU Length AAL5 Checksum Note: HEC and PAD not in memory IP Header IP Packet Length UDP Header UDP Packet Length AAL Length Same as IP Packet Length FPX Network Platform 16

9 Application Example Rot13 Encryption FPX Network Platform 17 The Layered Protocol Application Example Network data encryption / decryption using ROT13 algorithm Rotates characters by 13 places A N, M Z, a n, m z Encryption Example: Hello World encrypts to Uryyb Jbeyq Decryption Example: Uryyb Jbeyq decrypts to Hello World FPX Network Platform 18

10 The Rot13 Encryption Module D_MOD_IN SOC_MOD_IN TCA_MOD_IN UDPEcho Entity ROT13 Entity ROT13 Entity ROT13 Entity ROT13 Entity D_OUT_MOD SOC_OUT_MOD TCA_OUT_MOD PROTOCOL WRAPPERS CLK RESET_L ENABLE_L READY_L FPX Network Platform 19 Simulating the ROT13 Module (More) The input data coming into the module SOD ThelasttwovalidwordsaretheATMTrailer SOD indicates indicates SOF EOF SOF EOFDataEn indicates indicates the thestart indicates indicates the the of start of end start end an anthe of UDP of UDP an data an data Datagram Datagram is is Cell valid Cell FPX Network Platform 20

11 Simulating the ROT13 Module (More) The output data going out of the module The TheUDPPayload UDPPayloadhas hasbeen beenencrypted encrypted // decrypted decrypted FPX Network Platform 21 Acknowledgements Several Individuals have contributed to this work: Washington University Jon Turner Sarang Dharmapurikar Todd Sproull David Taylor Florian Braun Henry Fu James Moscola DaveLim Edson Horta Xilinx Dave Parlour FPX Network Platform 22