Achronix Speedster22i 10G/40G/100G Ethernet - Manual (Page 102)

102 UG029, September 6, 2013
Statistics Data Registers
Overview
The 10 / 40 / 100 Gigabit Ethernet Channelized MAC Core provides a set of signals per
segment which can be used to implement the statistics required in IEEE 802.3 basic,
mandatory and recommended Management Information packages (clause 30).
In addition, the MAC Core provides counter values to generate the applicable objects of the
Management Information Base (MIB, MIB-II) according to IETF RFC 2665 (including its
update to 10 Gbps) for SNMP (Simple Network Management Protocol) managed
environments. For monitoring applications, the RMON counters are available according to
IETF RFC 2819.
IEEE 802.3 Management Package
The IEEE Standard 802.3 clause 30 defines the mandatory and recommended IEEE 802.3
Management Packages for the managed objects oMacEntity and oPauseEntity. Please refer to
the according standard for a more detailed description of the attributes and objects.
IETF Management Information Base (MIB, MIB-II) Objects
The IETF RFC 2665 defines the Management Information Base (MIB, MIB-II) objects for the
Ethernet-like Interface Types. RFC 2665 details the MIB (MIB-II) objects for Ethernet
Interfaces, which are defined in a more generic manner in RFC 2863. RFC 2665 was updated
for 10 Gbps and released as RFC 3635.
IETF Remote Network Monitoring
The IETF RFC 2819 defines objects for managing remote network monitoring devices. These
objects are usually implemented in a dedicated device (Monitor/Probe) for traffic monitoring
and analysis within a network segment. Such a probe usually samples the values in a
periodic manner to give relative usage estimations rather than absolute values.
The RMON MIB counts good and bad packets, defined as follows:

Good Packets (valid frames): Good packets are error-free packets that have a valid
frame length. Valid Frame Length is defined as between 64 octets and FRM_LENGTH
(typical 1518 or 1522) octets long. This does not include framing bits (Preamble, SFD)
but includes the FCS field. They follow the form defined in IEEE 802.3 section 3.2.

Bad Packets (invalid frames): Bad packets are packets that have proper framing and
are therefore recognized as packets, but contain errors within the packet or have an
invalid length. On Ethernet, bad packets have a valid preamble and SFD, but have a
bad CRC, or are either shorter than 64 octets or longer than FRM_LENGTH
(1518/1522) octets.