Transition Networks
S4224 Web User Guide
33558 Rev. C
Page 213 of 669
MEP Configuration
S4224 MEP (Maintenance Entity Group End Point) configuration is done from the
Configuration
>
MEP
menu path.
A MEP (MEG End Point) is an endpoint in a Maintenance Entity Group (per ITU-T Y.1731).
The MEP establishes the path by collating all the LTR PDUs.
A
Down MEP
is a MEP residing in a Bridge that receives SOAM PDUs from, and transmits them towards,
the direction of the LAN. Note that in the MEF service model, the LAN is a transmission facility in the
egress direction, rather than towards the Bridge Relay Entity. Down MEP
An
Up MEP
is a MEP residing in a Bridge that transmits SOAM PDUs towards, and receives them from,
the direction of the Bridge Relay Entity.
A
MIP
(MEG Intermediate Point) is a SOAM point associated with a single MEG level (and a single
Maintenance Domain). A MIP can respond to SOAM protocols, but cannot generate requests. MIPs are
defined to be located at External Interfaces such as ENNIs (or UNIs). In practice, a MIP can also be used
in additional internal operator locations where monitoring is desired.
The default MEG Levels are shown below per MEF 30 (not all MEG levels are required in every
application).
The figure above shows pairs of MEPs and MIPs that may communicate across the OAM domains
discussed above. The figure also shows the hierarchical relationship between these domains. Note that
the orientations of the MEPs in the figure are for example only (not requirements).
Flow OAM is implemented as a set of features as per requirements in IEEE802.1ag and ITU-
T.Y1731/G.8021. Nodes can be configured as Maintenance End Point (MEP) or Maintenance
Intermediate Point (MIP) in an OAM domain to participate in the Flow OAM functionality.
Features such as Link Trace, Continuity Check and Alarm Indication Signal are provided in the
implementation.
IEEE802.1ag support is implemented with the features like Link Trace, Loopback and Continuity Check.
Message parameters are framed as per the IEEE standard when the Link Trace feature configuration
indicates IEEE Link Trace. The
LTM
(Link Trace Message) PDU is initiated by MEP. MIPs receive and
handle the PDU in a manner that allows the MEP to trace the path to the target MAC address. All
intermediate MIPs will forward the packet to the egress port for which the target MAC is learnt and at the
same time reply to the MEP with a
LTR
(Link Trace Reply). This continues until the PDU is received by
the management point with the target MAC. This entity does not forward the packet but replies to the
originator MEP.
