Performance Monitoring on Aggregated Ethernet Interfaces
Learn about performance monitoring features on aggregated Ethernet Interfaces. Refer the guidelines for configuring performance monitoring features before you configure performance monitoring.
ITU-T Y.1731 ETH-LM, ETH-SLM, and ETH-DM on Aggregated Ethernet Interfaces
Configure ITU-T Y.1731 standard-compliant Ethernet loss measurement (ETH-LM), Ethernet synthetic loss measurement (ETH-SLM), and Ethernet delay measurement (ETH- DM) capabilities on aggregated Ethernet (ae) interfaces. These ITU-T Y.1731 OAM services or performance monitoring techniques can be measured by on-demand mode (triggered through the CLI) or by proactive mode (triggered by the iterator application).
Connectivity fault management (CFM) sessions established on the AE interfaces can be distributed to the Packet Forwarding Engine, apart from being handled on the Routing engine. This capability to distribute CFM sessions is useful in both scaled topologies and gracful Routing Engine switchover (GRES) for CFM sessions.
To enable the distribution of CFM sessions and to operate in centralized mode, include the
ppm delegate-processing statement at the [edit routing-options
ppm] hierarchy level. The mechanism that enables distribution of CFM sessions over AE
interfaces provides the underlying infrastructure to support PM over AE interfaces. In addition,
periodic packet management (PPM) handles time-sensitive periodic processing and performs such
processes as sending process-specific packets and gathering statistics. With PPM processes
running distributed on both the Routing Engine and the Packet Forwarding Engine, you can run
performance monitoring processes on the Packet Forwarding Engine.
For Ethernet delay measurement, hardware-assisted timestamping is supported on AE interfaces, similar to the support that exists on non-AE interfaces. Only hardware-based timestamping is supported because it is performed in the received path of the protocol data unit (PDU) packets, whereas software-based timestamping needs to be performed on the transmitted path and is not supported.
Before you start an ETH-DM, ETH-LM, or ETH-SLM measurement sessions across an aggregated Ethernet
service, you must configure two routers to support these measurement sessions. On each router,
configure two physical or logical AE interfaces connected by a VLAN by including the
interface ae-fpc/pic/port unit logical-unit-number
vlan-id vlan-id statement at the [edit interfaces]
hierarchy level and on each router, attach the peer MEPs to the interfaces by including the
mep mep-id interface interface-name (protect | working)
statement at the [edit protocols oam ethernet connectivity-fault-management
maintenance-domain md-name maintenance-association
ma-name] hierarchy level.
Ethernet loss measurement over an aggregated Ethernet (ae) interface is not supported when the
enhanced LAG functionality is enabled on a router. The enhanced LAG capability is enabled by
default when you configure enhanced IP services mode by including the network-services
enhanced-ip statement at the [edit chassis] hierarchy level. For
Ethernet loss measurement to work properly, you must disable the enhanced LAG functionality by
entering the set chassis aggregated-devices disable-lag-enhanced statement.
Performance monitoring for connectivity fault management is not supported when the network-to-network (NNI) or egress interface is an aggregated Ethernet interface with member links on DPCs.
See Also
Guidelines to Configure Performance Monitoring on Aggregated Ethernet Interfaces
Keep the following points in mind while you configure ETH-LM, ETH-SLM, and ETH-DM capabilities on aggregated Ethernet (ae-) interfaces:
The scaling limits and performance considerations for distributed periodic packet management (PPM) sessions. The scaling limits for distributed PPM sessions over aggregated Ethernet (AE) interfaces are identical to the maximum supported numbers for continuity check messages (CCM) over AE interfaces.
SLA iterators always coexist with CCM sessions. Therefore, while configuring a scaled environment, you must account for CCM sessions should be accounted along with SLA iterators. The following table describes the maximum number of distributed PM sessions you can configure for different CCM intervals per line card and per router (system-wide value).
A mixed operation of distributed and centralized modes for performance monitoring (PM) sessions is not supported on AE interfaces, if the interfaces that form the aggregated Ethernet bundle are in mixed mode.
The limitations for performance monitoring (PM) capabilities for non-AE interfaces apply equally well for AE interfaces. For example, flapping of sessions resets the PM statistics.
The limitations that exist with distributed PPM sessions are valid for performance monitoring capabilities over AE interfaces because measurements are always performed on CCM sessions.
For ETH-LM over AE interfaces in an active-standby setup, if active and standby line cards are swapped, then the measurements during this window are ignored. Whenever the link failover from the active interface to the standby interface happens, the counters are reset.
For ETH-DM over AE interfaces, the additional time that is taken for packet transmission (packets are redirected to anchor in the received [Rx] direction and to the active child FPC in the transmitted [Tx] direction) is computed in the delay measurement.