Performance Measurement in OcNOS: Y.1731 OAM and Y.1564 Service Acceptance Testing

Performance measurement on OcNOS uses ITU-T Y.1731 for Carrier Ethernet OAM, monitoring frame delay, delay variation, and loss across a service, and Y.1564 (EtherSAM) to validate committed rate and KPIs before a service goes live. Together they prove SLA compliance at customer handoff, on OcNOS Carrier Ethernet platforms.

Carrier Ethernet services require two distinct types of performance measurement: continuous in-service monitoring to detect degradation over time, and one-time acceptance testing to verify the service meets its committed parameters before customer handoff. ITU-T Y.1731 covers the first; Y.1564 covers the second.

Platform note: Y.1731 and Y.1564 are hardware-assisted Carrier Ethernet OAM features. They run on OcNOS carrier-Ethernet platforms (Broadcom Qumran based) and are not available on the x86 OcNOS demo VM. Confirm support for your target platform in the OcNOS Feature Matrix.

This is Part 2 of the IP Infusion performance measurement series. Part 1 covers TWAMP for IP/MPLS networks.

Y.1731: Ethernet OAM for In-Service Monitoring

Y.1731 defines Ethernet Operation, Administration, and Maintenance (OAM) frames that measure performance metrics at Layer 2, within an Ethernet service domain (MEG) defined between two Maintenance End Points (MEPs). Unlike TWAMP which operates at IP level, Y.1731 measures at the Ethernet frame level, providing accurate performance data for carrier Ethernet services regardless of IP routing changes.

Key Y.1731 Measurement Functions

! OcNOS: Y.1731 MEG (domain + MA) and MEP configuration
! Interface names, MEP IDs and profile names are illustrative placeholders.
!
! Step 1: Define the maintenance domain and the service (Maintenance Association)
ethernet cfm domain-type character-string domain-name CARRIER-SERVICES level 4
 service ma-type string ma-name SVC001
  cc interval 1s
!
! Step 2: Define the Maintenance End Point (MEP)
!         ethernet cfm mep (down|up) mpid <1-8191> active (false|true) IFNAME
ethernet cfm mep down mpid 1 active true eth-0-1
!
! Step 3: Run a two-way delay measurement (DMM) as an EXEC action
delay-measurement type on-demand profile-name DM-1 rmep 2 start-time immediate repetition-period 6000 mep 1 domain CARRIER-SERVICES ma SVC001
!
! View delay measurement results
show ethernet cfm delay-measurement mep 1 domain CARRIER-SERVICES ma-name SVC001
! representative output: average / min / max frame delay and delay variation (jitter)

! OcNOS: Y.1731 Frame Loss Measurement (LMM) - EXEC action
!
loss-measurement type on-demand profile-name LM-1 rmep mep-id 2 start-time immediate stop-time none repetition-period 6000 mep 1 domain CARRIER-SERVICES ma SVC001
!
show ethernet cfm loss-measurement mep 1 domain CARRIER-SERVICES ma-name SVC001
! representative output: near-end loss, far-end loss, frame loss ratio

Y.1564: Service Acceptance Testing

Y.1564 defines a two-phase test procedure that validates a carrier Ethernet service meets its committed bandwidth, delay, and loss parameters before being handed over to the customer.

• Phase 1 (Service Configuration Test): verifies Committed Information Rate (CIR), Committed Burst Size (CBS), Excess Information Rate (EIR), and traffic policing behavior step by step at 25%, 50%, 75%, and 100% of CIR, then at EIR, then above EIR
• Phase 2 (Service Performance Test): runs traffic at 100% CIR for a configured duration (typically 15 minutes to 24 hours) and measures frame loss ratio, frame transfer delay, and delay variation against SLA thresholds

! OcNOS: Y.1564 service activation testing (SAT)
! Profile names and numeric values are illustrative placeholders.
!
! Step 1: Define the rate, frame-size and acceptance (SLA) profiles
ethernet sat rate-profile SVC-RATE
 cir 1000 mbps cos 6 dei 0
 eir 500 mbps cos 4 dei 1
 two-way
!
ethernet sat frame-size-profile SVC-FRAMES
 size-a 64
 size-b 128
!
ethernet sat acceptance-profile SVC-SLA
 cir frame-loss-ratio 0.0001
 cir frame-delay ms 100
!
! Step 2: Bind the profiles into a test definition
ethernet sat SVC-TEST
 direction upstream
 service-test cir-eir
!
! Step 3: Start the test (EXEC action)
sat start SVC-TEST
!
! Step 4: Monitor and view results
show ethernet sat summary
show ethernet sat detail SVC-TEST
! representative output: pass/fail per step, measured throughput / loss / delay vs thresholds

• Performance Measurement: TWAMP
• Flex-Algo with Measured Link Delay
• OcNOS-SP Product Page
• Contact IP Infusion

IP Infusion Engineering Team