Curtiss-Wright SSR/CHS/001/B, User Manual, Page: 27 / 34

C
HAPTER
3: O
PERATING A MULTI
-
ROLE RECORDER
23
N
OTE
: The notation used in this document is the standard bit ordering and numbering convention used in network -
ing known as
standard big-endian network byte order
. That is, the most significant octet is transmitted first;
the left-most bit of the entire field is the most significant bit.
The multi-role recorder performs three tasks:
• Packetizes acquired data in an iNET-X payload, which is then encapsulated as an IENA/UDP/IP or
iNET/UDP/IP packet. iNET-X payload formats are described in
TEC/NOT/067 - IENA and iNET-X packet
payload formats
.
• Transmits iNET packets over the network, allowing for real-time analysis and display of the acquired data.
N
OTE
: On the wire between successive Ethernet frames there is a mandatory minimum idle period. This
period has a duration of 12 bytes and is known as the Inter-Frame Gap (IFG). Following the IFG is a 7-
byte Preamble and 1-byte Start Frame Delimiter (SFD). The Ethernet frame begins with the Destination
MAC address in the MAC header.
• Writes and records the data to the CF card or SATA SSD cartridge. By default, only Ethernet packets
generated by the multi-role recorder’s backplane controller are recorded. However, the multi-role recorder can
be configured to record Ethernet packets received at the Ethernet port. This is configured using the SNMP
variable
.iso.org.dod.internet.private.enterprises.acra.recorder.ethernetRecording.0.
Setting this variable to 0 disables Ethernet recording but it does not disable Ethernet packets from the
SSR/CHS/001/B; setting it to 1 enables Ethernet recording. Both the recorded Ethernet and multi-role recorder
data packets are stored in a PCAP file format.
N
OTE
: For background information on the rules and guidelines for generating and recording Ethernet frames as
Wireshark PCAP files, see TEC/NOT/051 - Ethernet frames, Wireshark® and FAT32 .
For a more detailed description and discussion of iNET-X payload structures, see
TEC/NOT/067 - IENA
and iNET-X packet payload formats.
By default, all packet streams are recorded to the media. Multi-role recorders support filtering whereby a subset of
the packet streams can be selected for transmission. The filtered packet streams can be configured using SNMP.
Filtering can only be performed on multicast addresses and up to 16 multicast filters can be enabled. To enable a
filter, the dot1dStaticAddress variable is set with the required multicast MAC address as shown in the
following table.
Table 1: Multicast address filter examples
Filter
#
MAC address SNMP variable
SNMP variable
value
1 01:00:5e:00:00:02 .iso.org.dod.internet.mgmt.mib-
2.dot1dBridge.dot1dStatic.dot
1dStaticTable.dot1dStaticEntry.dot1dStaticAd -
dress.1
01005E000002
5 01:00:5e:00:00:0a .iso.org.dod.internet.mgmt.mib-
2.dot1dBridge.dot1dStatic.do
t1dStaticTable.dot1dStaticEntry.dot1dStati -
cAddress.5
01005E00000a
8 01:00:5e:00:01:05 .iso.org.dod.internet.mgmt.mib-
2.dot1dBridge.dot1dStatic.dot1
dStaticTable.dot1dStaticEntry.dot1dStaticAd -
dress.8
01005E000105