1. Washington WASHINGTON UNIVERSITY IN ST LOUIS fredk@arl.wustl.edu http://www.arl.wustl.edu/~fredk Fred Kuhns Applied Research Laboratory NSP packet Formats

2. 2 Washington WASHINGTON UNIVERSITY IN ST LOUIS fredk@arl.wustl.edufredk@arl.wustl.edu, 11/19/2015 Shim IP Header AAL5 Trailer IP Datagram Fragment offset (13) Ver (4)hlen (4)TOS (8)dgram length (16) Id (16)Flgs (3) TTL (8)Protocol (8)Header checksum (16) Source Address (32) Destination Address (32) IP Options ?? IP data (transport header and transport data) AAL5 padding (0 - 40 bytes: Set to Zero) CPCS-UU (0) Length (IP packet + SHIM) CRC (APIC/FPX calculates and sets) MSR Internal IP Packet Format 8 or 16 Bytes

3. 3 Washington WASHINGTON UNIVERSITY IN ST LOUIS fredk@arl.wustl.edufredk@arl.wustl.edu, 11/19/2015 FPX to SPC – Intra-Port Shim Input and Output VINs assumed correct. QID must be in the valid SPC range (1 – 127) Flag Values –DP (Drop Packet): SPC directive to FPX. Will always be zero coming into SPC. –RC (Reclassify Packet): SPC directive to FPX. May be 0 or 1 going to SPC. SPC must redefine. –NM (No Match): FPX can not classify (no route), FPX to SPC. Set to 0 before returning to FPX. –EX (Exception Packet): Requires non-fast path; IP options, Non IPv4. FPX to SPC. Set to 0 before returning to FPX. –HO (Header Only): FPX to SPC; Set if packet size > 120B and only first chunk sent to SPC. SPC must not modify. SPC can not drop internally if this bit is set. –HR (Header Only Return): Internal FPX flag. SPC must not modify. –FM (From LC/SW): Set by FPX. SPC can use but not modify. –TO (To LC/SW): Set by FPX. SPC can use but not modify. Flags Input VINOutput VINPPN Queue Identifier (QID) TTL Chunks Queue Length Packet Pointer Second Chunk Pointer DPRCNMEXHOHRFMTO Port #Sub #Port #Sub #Port # 031141111924

4. 4 Washington WASHINGTON UNIVERSITY IN ST LOUIS fredk@arl.wustl.edufredk@arl.wustl.edu, 11/19/2015 Input VINOutput VINPPN Port #Sub #Port #Sub #Port # FPX to SPC, Inter-port Shim Inter-port Shim – expect the Input and Output VINs to be correct. No other information needed – in particular the PPN is not used by the SPC. Likewise, the MTP is not used by the SPC. PPN : Default value 0x0 MTP : Default value 0x7f Flags MTP 031143111924

5. 5 Washington WASHINGTON UNIVERSITY IN ST LOUIS fredk@arl.wustl.edufredk@arl.wustl.edu, 11/19/2015 IP Packets (rfc 791) LLC/ SNAP IP Header AAL5 Trailer IP Datagram Fragment offset Version H-lengthTOSTotal length Identificationflags TTLprotocolHeader checksum Source Address Destination Address Options ?? Type (08.00)OUI (00.00) OUI (00)LLC (AA.AA.03) IP data (transport header and transport data) AAL5 padding (0 - 40 bytes) CPCS-UU (0) Length (IP packet + LLC/SNAP) CRC

6. 6 Washington WASHINGTON UNIVERSITY IN ST LOUIS fredk@arl.wustl.edufredk@arl.wustl.edu, 11/19/2015 IP Header Fields (rfc 791) Version - support IPv4 (4) Header Length - Length in 32 bit words (>= 5) TOS - Total Length - Length of datagram in octets Id - Assists in reassembling fragments Flags - Fragment Offset - Where fragment belongs, offset is in octets TTL - router must decrement, if 0 then discard packet Protocol - UDP/TCP/ICMP/RSVP to name a few Header Checksum - 16 bit one’s complement of the one’s complement sum of all 16 bit words in header Source Address - Sending hosts IP address Destination Address - Destination hosts IP address 0 DFDF MFMF TOS Precedence Field: 111 - Network Control 110 - Internetwork Control 101 - Critic/ECP 100 - Flash Override 011 - Flash 010 - Immediate 001 - Priority 000 - Routine Remaining TOS Fields: D - 1 = Low delay T - 1 = High Throughput R - 1 = High Reliability 0Prec.DTR0 DF - 1 = Don’t Fragment, MF - 1 = More Fragments

7. 7 Washington WASHINGTON UNIVERSITY IN ST LOUIS fredk@arl.wustl.edufredk@arl.wustl.edu, 11/19/2015 UDP data IP Header Fragment offset VersionH-lengthTOSTotal length IdentificationFlags TTLProtocolIP Header checksum IP Source Address IP Destination Address IP Datagram UDP header Layout of a UDP Packet UDP Checksum (16)Length (16) Destination Port (16)Source Port (16)

8. 8 Washington WASHINGTON UNIVERSITY IN ST LOUIS fredk@arl.wustl.edufredk@arl.wustl.edu, 11/19/2015 TCP data Window Size (16) Sequence Number (32) Destination Port (16)Source Port (16) IP Header Fragment offset VersionH-lengthTOSTotal length IdentificationFlags TTLProtocolIP Header checksum IP Source Address IP Destination Address IP Datagram TCP header Acknowledgment Number (32) hlen (4)Reserved (6)FSRPAU Checksum (16)Urgent Pointer (16) Layout of a TCP Packet

9. 9 Washington WASHINGTON UNIVERSITY IN ST LOUIS fredk@arl.wustl.edufredk@arl.wustl.edu, 11/19/2015 ICMP data IP Header Fragment offset VersionH-lengthTOSTotal length IdentificationFlags TTLProtocolIP Header checksum IP Source Address IP Destination Address IP Datagram ICMP header checksumtypecode