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EDM01-02: DAG 4.2S Card User Guide
©2005 31 Version 7: May 2006
Chapter 7:Data Formats
Introduction
The DAG 4.2S card supports a record format known as the Extensible
Record Format [ERF].
In this chapter This chapter covers the following sections of information.
Data Formats
Timestamps
7.1 Data Formats
Description
The DAG 4.2S card uses the ERF Types 1 and 3 timestamps. Timestamps
are in little-endian [Pentium native] byte order. All other fields are in big-
endian [network] byte order. All payload data is captured as a byte
stream, no byte re-ordering is applied.
Table Table 7-1 shows the Type 1 PoS HDLC record.
BYTE 3 BYTE 2 BYTE 1 BYTE 0
timestamp
timestamp
type 1 flags rlen
lctr wlen
HDLC Header
(rlen - 20) bytes of record
Table 7-1. Type 1 PoS HDLC Record.
Data format
The following is a description of the Type 1 PoS HDLC record field.
Field Description
HDLC Header Length may vary depending on protocol.
Table
Table 7-2 shows the Type 2 Ethernet record.
BYTE 3 BYTE 2 BYTE 1 BYTE 0
timestamp
timestamp
type 2 flags rlen
lctr wlen
offset pad rlen-18
bytes of record
Table 7-2. Type 2 Ethernet Record.