Chapter 8: Redundant Network Design; Physical Layer Redundancy; 100Base-Fx Fefi Recommendations - Avaya 8800 Planning And Engineering, Network Design

Chapter 8: Redundant network design

Provide redundancy to eliminate a single point of failure in your network. This section provides
guidelines that help you design redundant networks.

Physical layer redundancy

Provide physical layer redundancy to ensure that a faulty link does not cause a service interruption.
You can also configure the switch to detect link failures.
Physical layer redundancy navigation
•

100BASE-FX FEFI recommendations

• Gigabit Ethernet and remote fault indication
• SFFD recommendations
• End-to-end fault detection and VLACP
100BASE-FX FEFI recommendations
The Avaya Ethernet Routing Switch 8800/8600 supports Far End Fault Indication (FEFI). FEFI
ensures that link failures are reported to the switch. FEFI is enabled when the autonegotiation
function is enabled. However, not all 100BASE-FX drivers support FEFI. Without FEFI support, if
one of two unidirectional fibers forming the connection between the two switches fails, the
transmitting side cannot determine that the link is broken in one direction (see
FX FEFI on page 56). This leads to network connectivity problems because the transmitting switch
keeps the link active as it still receives signals from the far end. However, the outgoing packets are
dropped because of the failure.
June 2016
on page 55
on page 56
on page 56
on page 57
Planning and Engineering — Network Design
Comments on this document? infodev@avaya.com
Figure 12: 100BASE-
55