Nortel 8600 Configuration Manual

Also see for Passport 8600 Series: Reference guide Installation Product brief Installing Commissioning

Contents

18 Ethernet module fundamentalsenable autonegotiation on one port in a multilink trunk, you mustenable autonegotiation on all ports in the multilink trunk and disableSFFD.SFFD detects faults for a single link between two devices. You can alsouse Virtual Link Aggregation Control Protocol (VLACP) to detect link faultsend-to-end. For more information about VLACP, see Nortel EthernetRouting Switch 8600 Configuration — Link Aggregation, MLT, and SMLT(NN46205-518).For configuration examples and additional information about SFFD, seethe Single-Fiber Fault Detection Technical Configuration Guide on theNortel Technical Support Web site.802.3x flow control for Gigabit EthernetUse flow control to protect against packet loss. Flow control preventsEthernet ports from receiving more data than they can process.The 802.3x flow control mechanism is effective only at the Data Link Layer(Layer 2). When packets are routed, flow control packets are ignored.The Ethernet modules support IEEE 802.3x flow control in the followingways:• generate 802.3x flow control PAUSE frames when they becomecongested• respond to 802.3x PAUSE frames that enter from the other side of thelink• temporarily halt packet transmission when an 802.3x PAUSE frameis received from the remote endYou can enable flow control only on 1 Gigabit Ethernet (GbE) and 10Gbit/s ports. You cannot enable flow control for ports that run at less than1 Gbit/s.If you enable flow control, also configure the fc-pause-time parameter.This parameter sets the timer value placed in the MAC flow control PAUSEframe. This indicates to the link partner the length of time to pausetransmission.Maximum transmission unit and jumbo framesJumbo frames are larger than the maximum Ethernet frame size(maximum transmission unit, or MTU) specified in the IEEE 802.3standard. For untagged frames, the maximum standard size is 1518 bytes.For tagged frames, the maximum standard size increases by 4 bytes to1522 bytes.Nortel Ethernet Routing Switch 8600Configuration — Ethernet ModulesNN46205-503 04.01 21 December 2009Copyright © 2008-2009 Nortel Networks. All Rights Reserved.