A-1
Appendix A
AImplementation Profile

Buffers

Three types of buffers are essential to the execution of Surveyor’s features:

How Resources Use Buffers

Surveyor supports THGm, Portable Surveyor 10/100 Ethernet Analyzer Card, and
NDIS (10/100 Ethernet) LAN interfaces. Buffering is implemented with these
interfaces as described in Table A-2.
Table A-1. Buffer Types Used By Surveyor
Buffer Type Description
Real-Time (Monitor)
Buffer
A real-time buffer provides the transient data storage area for on-the-
fly frame analysis which, in conjunction with MAC statistics and error
counters, produces real-time LAN analysis and monitoring informa-
tion. Data captured from the network is copied to this area after filter-
ing. The data is immediately available for evaluation, and for
streaming copy to disk, after which it is discarded from the buffer.
Capture Buffer A capture buffer provides a durable data store of LAN traffic filtered
and captured in real-time, which is kept for later analysis or saved to
disk. The capture buffer is a “wrap-around” buffer; once filled, it begins
filling again from the beginning and older data is lost unless saved to
disk.
Transmit Buffer A transmit buffer is used as storage for pac kets to be transmitted
when performing network or LAN component testing. The transmit
buffer stores traffic which can be transmitted on the network.