Defined in four IETF drafts, BFD is a protocol that provides rapid detection of forwarding plane faults and link failures in IP/MPLS networks, thereby enabling faster fault recovery and service restoration. This is particularly important in Ethernet networks, which have no native fault-recovery mechanism and consequently could create longer service outages. BFD deployment is therefore essential for ensuring reliable delivery of any delay-sensitive data such as triple-play services or WAN-based application services operating over Ethernet infrastructure.

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The central theme in BFD testing is detection of Ethernet forwarding plane connectivity via a keep-alive mechanism to reduce fault detection times and accelerate service restoration to the de-facto 50 ms SONET/SDH benchmark. Using a single-platform test tool that is able to do both emulation and conformance testing ensures rapid and easily-obtained results.

For BFD testing, some typical testing challenges include:

• Quantifying recovery time from BFD session 'down'
• Characterizing scalability/performance trade-offs by emulating 1000's of BFD sessions
• Negative testing via constructing non-standard BFD control packets
• Verifying BFD three-way handshake, poll sequence, echo functions and multi-hop paths
• Ensuring interoperability via comprehensive conformance testing to IETF drafts
• Regression testing to ensure software integrity is maintained with subsequent releases

A typical emulation-based BFD test scenario that can be done on N2X is outlined below.

Test objective: Verify LSP reroute after BFD 'Down' to test that BFD fault detection triggers MPLS Fast Re-Route, and quantify service restoration time.

Test Steps

1. Emulate MPLS routers with BFD; setup multiple LSPs and backup LSPs; use LSP Ping between Test Port A and Test Port B to verify LSP connectivity
2. Initiate BFD 'Down' at Port B, forcing reroute to backup LSPs via Port C
3. Use LSP Ping/Trace to verify connectivity and path (for each LSP) at Port C, measure fast reroute time, and measure impact of reroute on ping echo delay

>> MPLS/IP Core Webpage | Carrier Ethernet Webpage | BFD Protocol Emulation Software Datasheet | Carrier Ethernet Protocol Conformance Test Suites Datasheet | IPv4/IPv6 Conformance Test Suites Datasheet | Press Release | Back to top

The industry-first N2X N5583A Bidirectional Forwarding Detection (BFD) Protocol Emulation Software enables easy testing of an IP/MPLS device's BFD implementation against many thousands of emulated BFD devices, enabling robustness and recovery performance validation in carrier-scale networks without a costly or difficult-to-obtain test-bed of real devices.

The BFD emulation suite is complemented with a new BFD conformance suite that tests device compliance to IETF standards. By releasing both products on a single platform, N2X delivers the world's first test tool to measure the performance as well as ensure the interoperability of BFD-enabled devices in very large, multi-vendor networks.

Key features of the N2X BFD emulation suite include:

• Up to 20ms detect times and 10ms transmit/receive intervals on XS-2 cards
• Co-operation with N2X Graceful Restart and MPLS Fast Reroute features
• Supports all test interfaces - Ethernet, POS, ATM, FR
• BFD up/down timestamps for convergence testing
• Transmit and receive diagnostic codes to determine session down cause
• Statistics such as BFD packet counts, inter-arrival times and state transition counters

Key features of the N2X BFD conformance suite include:

• Comprehensive test coverage comprising ~150test cases
• Includes MPLS test case coverage to IETF draft-ietf-bfd-mpls-05.txt
• Operates within the Industry-leading N2X Conformance Test Manager which contains powerful features such as a real-time protocol trace, that is clickable on any trace segment to display decodes

>> MPLS/IP Core Webpage | Carrier Ethernet Webpage | BFD Protocol Emulation Software Datasheet |Carrier Ethernet Protocol Conformance Test Suites Datasheet | IPv4/IPv6 Conformance Test Suites Datasheet | Press Release | Back to top

The N5583A N2X Bidirectional Forwarding Detection (BFD) Protocol Emulation Software is available on the Agilent N2X platform from Release 6.9 onwards. A product video that demonstrates how to test BFD using the N5583A emulation is accessible at the link below. Please contact your local Agilent representative for a live product demonstration of this emulation or the N5519A BFD conformance test suite at your site.

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

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Agilent N2X - The most comprehensive multi-service test solution for converging network infrastructures.