CANOGA PERKINS 9145EMP NID Software Version 3.1 User Manual
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Service OAM
9145EMP NID Software User’s Manual
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11.1.2 Logical Positioning of MEPs and MIPs
Untagged down MEPs can be configured on each physical User port. On the Network side, if
LAG is disabled, an untagged down MEP can be configured on the active network port. If LAG is
enabled, a single untagged down MEP can be configured on the LAG.
Figure 11-1 describes the logical positioning of MEPs in the 9145EMP system. We can distin-
guish several types of MEPs:
•
Untagged MEPs, described above (and designated in dark blue in Figure 11-1).
•
Down C-Tag MEPs facing the User port: These MEPs can be used to monitor the C-
VLAN connections between the CPE and the 9145EMP.
•
Up C-Tag MEPs, located on the user port (facing the VLAN multiplexing point): These
MEPs are used to monitor C-VLAN connectivity from the 9145EMP towards the network
core.
For the 9145EMP, the SOAM frames initiated by those MEPs are immediately
encapsulated in the S-VLAN tag corresponding to the MEP's C-Tag, as per VLAN
multiplexing records. Hence, the SOAM frames are not visible inside the Provider network
(unless the network is able to inspect double tagged SOAM frames); only the far-end
demultiplexing point is able to process those frames.
•
Up S-Tagged MEPs: These MEPs are monitoring the S-VLAN aggregation, which
originates in the 9145EMP. The frames are single tagged (with a single S-Tag) when sent
on the Network port.
Logically, the up S-Tag MEPs are attached to the virtual C-S connector port, which is a
proxy on the S component, for the User port. Hence, the SOAM frames issued by those
MEPs have the MAC address of the corresponding User port. Interface Status TLV for
the CCM frames issued by those MEPs carry the operational state of the User port. The
corresponding User port (for an S-Tagged MEP) is determined based on the VLAN
multiplexing record configuration.
There are no up MEPs on the Network side, as there no domain starting towards the User ports.
MIPs can be located only on C-VLANs, on the User port. The S-VLAN domain starts in the 9145E
device, so there is no need for an intermediate monitoring port.