Endace Measurement Systems Limited
http://www.endace.com
EDM01.05-04r1 DAG 3.6GE User Manual
Copyright, all rights reserved.
28
Revision 7. 22 September 2005.
6.1 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.
offset:
Number of bytes *not* captured from start of
frame.
Typically used to skip link layer headers when
not required in order to save bandwidth and
space.
This field is currently not implemented, contents
can be disregarded.
Continued on next page
