2 Rec. ITU-T Y.1564 (02/2016)
[IEEE 802.1Q] IEEE 802.1Q-2003, IEEE Standards for Local and Metropolitan Area
Networks – Virtual Bridged Local Area Networks.
[MEF 10.2] Technical Specification MEF 10.2 (2009), Ethernet Services Attributes,
phase 2.
3 Definitions
3.1 Terms defined elsewhere
None.
3.2 Terms defined in this Recommendation
This Recommendation defines the following terms:
3.2.1 Ethernet virtual connection (EVC) (derived from [MEF 10.2]: An association of two or
more user network interfaces (UNIs) that limits the exchange of service frames between these
interfaces.
3.2.2 information rate: The average bit rate of Ethernet service frames at the measurement point
(MP) starting with the first medium access control (MAC) address bit and ending with the last frame
check sequence (FCS) bit.
NOTE – Refer to [MEF 10.2] for a clear discussion of Ethernet service frames and specific examples of
information rate –the committed information rate (CIR) and the excess information rate (EIR). So, for instance,
a 100 Mbit/s Ethernet port can handle a total information rate of about 77 Mbit/s to 99 Mbit/s depending on
the average frame size of the transmitted Ethernet frames.
3.2.3 service activation: The step of bringing a network feature into operation for eventual use by
a customer, prior to customer notification that the feature is ready to use.
3.2.4 service activation test methodology: The procedures performed after service activation in
order to verify that a newly operational network feature to be used by a customer is working properly
prior to customer notification that the feature is ready to be used.
3.2.5 service acceptance criteria: A set of criteria used to ensure that a service meets its
functionality and quality requirement and that the service is ready to operate when it has been
deployed.
3.2.6 test flow: A protocol-compliant frame-size pattern used to simulate a stream of service
frames and provide the basis for measurements and test results. Each unique test flow shall be
categorized by its source and destination address and other header information, such as quality of
service (QoS)/class of service (CoS) at the Ethernet layer (all eight [IEEE 802.1Q] priorities) and
optionally the IP layer. Protocol layer configurations above IP layer may be used as part of the flow
configuration because the network under test might require these layers to transmit data between
source (SRC) and destination (DST).
3.2.7 utilized line rate: The average bit rate of the Ethernet line at the measurement point,
including the bits a) allocable to the minimum-duration period of each interframe gap (but not the
number of bits allocable to the part of each interframe gap longer than the minimum duration), b) in
the preamble, c) in the start of frame delimiter and d) in the Ethernet service frame starting with the
first MAC address bit and ending with the last FCS bit.
NOTE – This rate is calculated before the expansion effect of using code substitution at the physical layer. So
for instance, a 1 Gbit/s Ethernet port has a 1 Gbit/s maximum Utilized Line Rate even though the 8/10 bit code
substitution runs the actual physical interface at 1.25 Gbit/s.