2.2. Ethernet Parameters

Ethernet Parameters and PCAP Library

Ethernet parameters include Mapping, TOS/DSCP Changed, TTL Changed, Src address, Src MAC, Dst MAC, Maximum Inter-packet Arrival Time (maxIAT), Min IAT, Avg IAT, MDI Media Delivery Index [Delay factor (DF): Media Loss Rate (MLR)], MLT/MLS 15, MLT/MLS 24, Several broadcasters (see detailed description in the Parameters, events and errors chapter).

The parameters calculation is based on the library libpcap for Linux applications and on Npcap for Windows applications. The probe does not calculate the stated parameters if the corresponding library has not been installed in your OS. Moreover, root privileges are required to start a probe in Linux OS (sudo ./streamMonitor). See more information about libraries and privileges in the Starting the Probe chapter. There are alternative options for data receipt applied for some parameters. These parameters are displayed without pcap driver.

Ethernet Parameters Calculation Based on Different OS Restrictions

Feature	Linux	Windows
Ethernet parameters calculation: IAT, MLR, DF	Probe is started with root privileges sudo ./streamMonitor	The Npcap packet capture library should be installed on the PC before a probe starts. While installing the library, WinPcap API-compatible Mode and Support Loopback Traffic options should be selected.
Localhost Ethernet parameters calculation (127.0.0.1).	No restrictions.	No restrictions 1.
Ethernet parameters calculation based on timestamps set by a network adapter (high accuracy of calculation)	Supported. This mode is used automatically (if the adapter supports it).	Not supported.

1

Localhost IAT calculation is not available for WinPcap library. Please use Ncap instead.

Maximum Inter-Packet Arrival Time (MaxIAT)

Maximum Inter-packet Arrival Time (MaxIAT) – is maximum time between packets arrival. Packet jitter can be detected by checking inter-packet arrival time. Maximum IAT is defined as a summary of average IAT and jitter. Maximum IAT value is measured each second.