Carriers are increasingly adopting Ethernet infrastructure because it is potentially cheaper to install and run compared to SONET/SDH, Frame Relay or ATM. Equipment manufacturers are developing and standardizing new technologies such as E-OAM, BFD, MSTP, LACP, and PBB/PBT to improve Ethernet's robustness and manageability.

E-OAM Fault Management, described in IEEE 802.1ag and ITU Y.1731, detects, verifies and isolates Ethernet faults from end-to-end, using three message types: Loopback (a layer-2 ping); Link Trace (a layer-2 Traceroute); and Continuity Check (CC - a regular heartbeat).

Equipment manufacturers and service providers who are developing or deploying Fault Management face many test challenges (see Figure 1). For example:

• Performance - What is the optimal CC timer value to use, in the presence of other line-card processing?
• Scalability - How many Ethernet Managed End Points (MEPs) and Managed Intermediate Points (MIPs) can be supported?
• Interoperability - Will incompatible Fault Management frames from another vendor cause faults?

Figure 1 - Click to enlarge

For more background on Carrier Ethernet test issues and related solutions, please see our resources on the N2X Carrier Ethernet webpage.

>> N2X Carrier Ethernet Webpage | Back to top

Verifying Ethernet OAM, like any data communications technology, requires two complementary test methodologies: (see Figure 2)

• Emulation: N2X can emulate one MEP or MIP, or thousands of Ethernet devices, by implementing the 802.1ag and Y.1731 control plane protocols and sending data plane traffic. This allows you to quantify functionality, performance and scalability without huge racks of equipment.

  For example, N2X can verify that Remote Defect Indication (RDI) is raised when a CC message for an expected MEP is not received within 3.5 times the CC interval. (see Figure 3)

• Conformance: N2X can verify your device's conformance to MEF, IEEE, IETF and ITU standards (such as IEEE 802.1ag Connectivity Fault Management) to help ensure interoperability with equipment from other vendors.

  For example, N2X can verify that a MEP's CC messages are sent to the group MAC address corresponding to the Maintenance Domain level. (see Figure 4)

Figure 2	Figure 3	Figure 4
Click to enlarge

 

For more information on testing Carrier Ethernet devices, please see our whitepaper and archived Agilent-LightReading webinar at the links below:

>> Carrier Ethernet Whitepaper | Agilent-Light Reading Webinar: Carrier Ethernet Implementation: How to Profit without the Pain | N2X Carrier Ethernet Webpage | Back to top

Agilent N2X offers the most comprehensive solution for verifying Carrier Ethernet technologies, including E-OAM, BFD, STP/RSTP/MSTP, LACP, VPLS, PBB/PBT, VLANs, and MEF 9 and 14.

For E-OAM Fault Management emulation, N2X gives you the choice of the N5581A CFM (802.1ag), N5585A Fault Management (Y.1731), or N5587A E-OAM Fault Management (802.1ag and Y.1731) Emulation software. Key features include: (see Figure 5)

• Emulate Fault Management messages over Ethernet and VPLS
• Use with other N2X emulations, such as xSTP and LACP
• Easily emulate thousands of Maintenance Points to characterize scalability
• Comprehensive Continuity Check Database (CCDB) with stateful feedback
• Integration of Loopback and Link Trace with CCDB
• Verify FM functionality across multiple domain levels
• Quantify Link Trace and Loopback latency

To test conformance, the N5718A CFM Conformance Test Suite offers these key features: (see Figure 6)

• Verify all four categories of Ethernet CFM mechanisms with over 150 test cases: Continuity Check, Loopback, Link Trace, and Fault Alarms
• Industry-leading Test Manager simplifies conformance testing
• Rapid result diagnosis and problem isolation
• Easily extendable test suite
• Automatic configuration and control of the device under test
• Comprehensive test documentation and reporting tools

Figure 5	Figure 6
Click to enlarge

>> E-OAM CFM Emulation Software datasheet | E-OAM Fault Management (Y.1731) Emulation Software datasheet | Carrier Ethernet Protocol Conformance Test Suites datasheet | N2X Carrier Ethernet Brochure | N2X Carrier Ethernet Webpage | Back to top

The E-OAM Fault Management emulations and conformance test software are available on the N2X platform from release 6.10 onwards. A product video that demonstrates how to test E-OAM Fault Management with the Agilent N2X will be made available shortly at the link below. Please contact your local Agilent representative for a live product demonstration at your site.

Ethernet OAM Demo Video

>> N2X Release 6.10 | Demo Video | N2X Carrier Ethernet Webpage | Back to top

Click here to contact your local Agilent representation for more information.

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