Transition Networks, Inc.
S4224 Web User Guide
33595 Rev. C
Page 651 of 669
LOAM
(Link OAM) Ethernet Connectivity Fault Management (CFM) provided per IEEE 802.3ah OAM. The major
features covered by this protocol are Discovery, Link Monitoring, Remote Fault Detection, and Remote
Loopback. The S4224s support both Link layer OAM (LOAM, per IEEE 802.3–2005
Clause 57) and Service layer OAM (SOAM, per IEEE 802.1AG and Y.1731). Compare to “SOAM”.
LOC
LOC (Loss Of Connectivity) is detected by a MEP and indicates lost connectivity in the network. LOC can be
used as a switch criteria by EPS.
M
MAC Swap
In SOAM testing, MEPs need to know about the device on the other side. They perform a MAC Swap so they
can automatically populate the remote MAC Address to the test parameters. This is performed in Layer 2.
See the S4224
Configuration
>
MEP
menu path description.
MAC Table
Switching of frames is based upon the DMAC address contained in the frame. The switch builds up a table that
maps MAC addresses to switch ports for knowing which ports the frames should go to ( based upon the DMAC
address in the frame ). This table contains both static and dynamic entries. The static entries are configured by
the network administrator if the administrator wants to do a fixed mapping between the DMAC address and
switch ports.
The frames also contain a MAC address (SMAC address ), which shows the MAC address of the equipment
sending the frame. The SMAC address is used by the switch to automatically update the MAC table with these
dynamic MAC addresses. Dynamic entries are removed from the MAC table if no frame with the corresponding
SMAC address have been seen after a configurable age time.
Major ring
The Ethernet ring that is connected on two ports to an interconnection node. From ITU-T Rec.G.8032/Y.1344
(03/2010).
Master clock
In the context of a single PTP communication path, a clock that is the source of time to which all other clocks on
that path synchronize. A system of 1588 clocks may be segmented into regions separated by boundary clocks.
Within each region there will be a single clock, the master clock, serving as the primary source of time. These
master clocks will in turn synchronize to other master clocks and ultimately to the grandmaster clock.
MD5
MD5 (
M
essage-
D
igest algorithm
5
is a message digest algorithm used in a cryptographic hash function with a
128-bit hash value. It was designed by Ron Rivest in 1991. MD5 is officially defined in RFC 1321 - The MD5
Message-Digest Algorithm. MD5 is an authentication protocol; one of two cryptography methods used for S4224
user authentication. MD5 is a widely used cryptographic hash function with a 128-bit hash value. Specified in
RFC 1321, MD5 is used in a wide range of security applications, and is also commonly used to check file
integrity. However, it has been shown that MD5 is not collision resistant; as such, MD5 is not suitable for
applications like SSL certificates or digital signatures that rely on this property. MD5 was designed by Ron
Rivest in 1991 to replace the earlier hash function MD4. See also “SHA”.
ME
(Maintenance Entity) An entity that requires management and is a relationship between two maintenance entity
group (MEG) end points. MEs in Ethernet networks can nest but not overlap.
MED
Media Endpoint Discovery.
