
IBM3206K0424
Preliminary
IBM Processor for Network Resources
pnr25.chapt03.01
August 14, 2000
Packet Header
Page 63 of 676
EFCT_status
This bit is used on both transmit and receive:
Transmit - If this bit is set, the EFCI bit in the ATM cell header will be set for each cell in this packet.
Receive - This bit contains the ORed EFCI bits across all the cells that comprised this packet if this LCD is
using AAL5.
cell_loss_priority
This bit is used on both transmit and receive:
Transmit -If this bit is set, the cell loss priority bit in the ATM cell header will be set for each cell in this packet
Receive - This bit contains the ORed cell loss priority bits across all the cells that comprised this packet if this
LCD is using AAL5.
buffer_offset
This field contains the offset into the buffer where the data starts.
buffer_length
This field contains the length of the packet.
lc_address
This is the address of the logical connection descriptor on which this packet was received.
rx_atm_header
On reception, the four-byte ATM header (no HEC) is copied from the first and last cell into this area. This is an
optional header word.
AAL5_user_byte2 (tx)
This field contains the value to be sent in the user bytes, one and two, in the last cell of an AAL5 packet if
INTST is configured for two-user byte. The normal one-byte AAL5 user byte field is not used.
AAL5_user_byte2 (rx)
This field contains the AAL5 user bytes, one and two, in the last cell of an AAL5 packet if INTST is configured
for two-user byte. The normal one-byte AAL5 user byte field is not filled in. This is an optional packet header
word.
bit16 rx_label
This field is written with "RA" in ASCII (0x5241) to signal that this buffer was used by RAALL.
bit2 ip_chksm_flags
This field contains the IP checksum status if enabled. The possible values are:
00
Not checked
01
Good
10
Bad
11
Unknown
bit2 proto_chksm_flags
This field contains the protocol checksum status if enabled. The possible values are:
00
Not checked
01
Good
10
Bad
11
Unknown
bit1 toobig_status
Indicates the current packet exceeded the maximum packet size.
bit1 memchk_status
Indicates the current packet had a memory check (real size exceeded or virtual error).
bit1 fabort_status
Indicates the current packet was aborted (AAL5 forward abort).
bit1 badlen_status
Indicates the current packet had a bad AAL5 length in the trailer.
bit1 badcpi_status
Indicates the current packet had a bad AAL5 CPI field (not zero).
bit1 badcrc_status
Indicates the current packet had a bad AAL5 CRC.
bit1 route_status
This bit is written when the packet is completed if it is internally routed.
bit1 error_status
This bit is written when the packet is completed if an error condition occurs.
bit1 done_status
This bit is written when the packet is completed. It can be used when thresholding.
host_data
This is an optional word that can be copied from the LCD to the packet header.
Transmit and Receive Packet Header Field Descriptions
(Page 2 of 3)
Field Name
Field Description