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The Spanning Tree Protocol (STP) is a network protocol that builds a loop-free logical topology for Ethernet networks. The basic function of STP is to prevent bridge loops and the broadcast radiation that results from them. Spanning tree also allows a network design to include backup links providing fault tolerance if an active link fails.
A virtual LAN (VLAN) is any broadcast domain that is partitioned and isolated in a computer network at the data link layer. LAN is the abbreviation for local area network and in this context virtual refers to a physical object recreated and altered by additional logic. VLANs work by applying tags to network frames and handling these tags in networking systems – creating the appearance and functionality of network traffic that is physically on a single network but acts as if it is split between separate networks. In this way, VLANs can keep network applications separate despite being connected to the same physical network, and without requiring multiple sets of cabling and networking devices to be deployed.
In computer networking, link aggregation is the combining of multiple network connections in parallel by any of several methods, in order to increase throughput beyond what a single connection could sustain, to provide redundancy in case one of the links should fail, or both. A link aggregation group (LAG) is the combined collection of physical ports.
Unidirectional Link Detection (UDLD) is a data link layer protocol from Cisco Systems to monitor the physical configuration of the cables and detect unidirectional links. UDLD complements the Spanning Tree Protocol which is used to eliminate switching loops.
EtherChannel is a port link aggregation technology or port-channel architecture used primarily on Cisco switches. It allows grouping of several physical Ethernet links to create one logical Ethernet link for the purpose of providing fault-tolerance and high-speed links between switches, routers and servers. An EtherChannel can be created from between two and eight active Fast, Gigabit or 10-Gigabit Ethernet ports, with an additional one to eight inactive (failover) ports which become active as the other active ports fail. EtherChannel is primarily used in the backbone network, but can also be used to connect end user machines.
Cisco Inter-Switch Link (ISL) is a Cisco Systems proprietary protocol that maintains VLAN information in Ethernet frames as traffic flows between switches and routers, or switches and switches. ISL is Cisco's VLAN encapsulation protocol and is supported only on some Cisco equipment over the Fast and Gigabit Ethernet links. It is offered as an alternative to the IEEE 802.1Q standard, a widely used VLAN tagging protocol, although the use of ISL for new sites is deprecated by Cisco.
Provider Backbone Bridge Traffic Engineering (PBB-TE) is an approved telecommunications networking standard, IEEE 802.1Qay-2009. PBB-TE adapts Ethernet technology to carrier class transport networks. It is based on the layered VLAN tags and MAC-in-MAC encapsulation defined in IEEE 802.1ah, but it differs from PBB in eliminating flooding, dynamically created forwarding tables, and spanning tree protocols. Compared to PBB and its predecessors, PBB-TE behaves more predictably and its behavior can be more easily controlled by the network operator, at the expense of requiring up-front connection configuration at each bridge along a forwarding path. PBB-TE Operations, Administration, and Management (OAM) is usually based on IEEE 802.1ag. It was initially based on Nortel's Provider Backbone Transport (PBT).
Port Aggregation Protocol (PAgP) is a Cisco Systems proprietary networking protocol, which is used for the automated, logical aggregation of Ethernet switch ports, known as an EtherChannel. The PAgP is proprietary to Cisco Systems. A similar protocol known as LACP — released by the IEEE and known as 802.3ad or 802.1ax recently — is an industry standard and is not tied to a specific vendor.
Multi-link trunking (MLT) is a link aggregation technology developed at Nortel in 1999. It allows grouping several physical Ethernet links into one logical Ethernet link to provide fault-tolerance and high-speed links between routers, switches, and servers.
Virtual LACP (VLACP) is an Avaya extension of the Link Aggregation Control Protocol to provide a Layer 2 handshaking protocol which can detect end-to-end failure between two physical Ethernet interfaces. It allows the switch to detect unidirectional or bi-directional link failures irrespective of intermediary devices and enables link recovery in less than one second.
Metro Ethernet Routing Switch 8600 or MERS 8600 is a modular chassis router and/or switch manufactured by Nortel now acquired by Ciena. The MERS 8600 supports the Provider Backbone Bridges (PBB), Provider Backbone Transport (PBT) technologies and carrier class Operations Administration & Maintenance (OAM) tools.
In network routing, the control plane is the part of the router architecture that is concerned with drawing the network topology, or the information in a routing table that defines what to do with incoming packets. Control plane functions, such as participating in routing protocols, run in the architectural control element. In most cases, the routing table contains a list of destination addresses and the outgoing interface(s) associated with each. Control plane logic also can identify certain packets to be discarded, as well as preferential treatment of certain packets for which a high quality of service is defined by such mechanisms as differentiated services.
The Avaya Ethernet Routing Switch 8600 or ERS 8600, previously known as the Passport 8600 or the Accelar 8000, is a modular chassis combination hardware router and switch used in computer networking. The system, originally designed and manufactured by Nortel, was manufactured by Avaya from 2009 until 2017. The system provided the 10G Ethernet equipment backbone for the 2010 Winter Olympics games, providing service for 15,000 VoIP Phones, 40,000 Ethernet connections and supporting 1.8 million live spectators. The system is configurable as a 1.440 Terabit Switch cluster using SMLT and R-SMLT protocols, to provide high reliability cluster failover.
A multi-chassis link aggregation group is a type of link aggregation group (LAG) with constituent ports that terminate on separate chassis, primarily for the purpose of providing redundancy in the event one of the chassis fails. The IEEE 802.1AX-2008 industry standard for link aggregation does not mention MC-LAG, but does not preclude it. Its implementation varies by vendor; notably, the protocol existing between the chassis is proprietary.
Simple Loop Prevention Protocol (SLPP) in computer networking is a Data Link Layer protocol developed by Nortel to protect against Layer 2 network loops. SLPP uses a small hello packet to detect network loops. The SLPP protocol checks packets from the originating switch and the peer switch in a SMLT configuration. Sending hello packets on a per VLAN basis allows SLPP to detect VLAN based network loops for un-tagged as well as tagged IEEE 802.1Q VLAN link configurations. If a loop is detected, the associated port is shut down.
Shortest Path Bridging (SPB), specified in the IEEE 802.1aq standard, is a computer networking technology intended to simplify the creation and configuration of networks, while enabling multipath routing.
Avaya Virtual Services Platform 9000 Series or VSP 9000 is a set of modular chassis switches used in enterprise and data center networks, manufactured by Avaya. The VSP 9000 is used by institutions which are suffering from performance limitations, need to simplify their network infrastructure in a virtualized environment, or require 10 Gigabit Ethernet today with the option to scale to 40 or 100 Gigabit Ethernet in the future. It is also an option for companies who are looking to reduce the power and cooling cost in order to maximize the cost-effectiveness of their infrastructures; this unit was also designed and is expected to have a lifespan of seven-to-ten years. In 2013 the Olympics network backbone is built with VSP 9000 Switches supporting 30,000 users and up to 54 terabits per second of traffic.
