M A G N U M 6 K S W I T C H E S , M N S - 6 K U S E R G U I D EChapter1414 – S-Ring™ and Link-Loss-Learn™(LLL)Speed up recovery from faults in Ethernet networksS -Ring uses ring topology to provide fast recovery from faults. These are based onindustry standard STP technologies. These technologies have been adapted to ringrecovery applications by GarrettCom Inc. and these rings are called S-Ring. Inaddition, LLL enables a switch to rapidly re-learn MAC addresses in order toparticipate in S-Ring configurations. One advantage of S-Ring is that the fastrecovery works with managed as well as some non managed switches as well.In the last two chapters we looked at how RSTP or STP can be used to bringresiliency to a meshed network. This chapter’s focus is to look at ring topologies andhow these topologies can be used to provide faster recovery times than what STP orRSTP can offer. Both RSTP and STP are industry standard protocols and can beused with networking switches from different vendors.LLL triggers action on the device supporting LLL when a connection is broken orthere is loss of the link signal on a ring port. LLL can be used with S-Ring onmanaged switches such as the GarrettCom Magnum 6K family of switches. LLL canalso be used on managed switches such as Magnum 6K family of switches, MagnummP62 as well as on unmanaged switches such as ESD42 switches. Note that LLLcan also be used with non-ring topologies (such as mesh topologies) using RSTP orSTP where it does the necessary actions for fault recovery (such as re-learnaddresses) in case of a link failure.S-Ring is a ring technology using the GarrettCom MNS-6K software. In a S-Ring, aswitch is designated as a “Ring Manager”. Devices in a S-Ring can be managedswitches such as the Magnum 6K family of switches, other managed switches such asMagnum mP62 or unmanaged switches such as ESD42 or even hubs whichleverages LLL. S-Ring is a licensed product from GarrettCom Inc. GarrettCom Inc.also licenses this technology to other companies who are interested in implementingthe resiliency capabilities offered by S-Ring.174
