EDM 01-11v8 DAG 6.1S Card User Guide
©2005
37
Version 8: May 2006
7.1 Data Formats
, continued
Data Format
Description
flags:
This byte is divided into 2 parts, the interface
identifier, and the capture offset.
1-0: capture interface 0-3
2: varying record lengths present
3: truncated record [insufficient buffer space]
4: rx error [link error]
5: 5: ds error [internal error]
7-6: reserved
Rlen: record length
Total length of the record transferred over PCI
bus to storage.
Lctr:
loss counter
A 16 bit counter, recording the number of
packets lost since the previous record. Records
can be lost between the DAG card and memory
hole due to overloading on PCI bus. The
counter starts at zero, and sticks at 0xffff.
Wlen:
wire length
Packet length including some protocol overhead.
The exact interpretation of this quantity depends
on physical medium.
Table
Table 7-2 shows the Type 1 POS HDLC variable length record. The
diagram is not to scale.
timestamp
timestamp
type:1
flags
rlen
lctr
wlen
HDLC Header
(rlen - 20) bytes of packet
Table 7-2. Type 1 POS HDLC Variable Length Record.
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