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90 Cards in this Set

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Address Resolution Protocol table is used by a Layer 3 device (router, switch, server, desktop) to store the IP address to MAC address entries for a specific network device. The ARP table allows a device to resolve a Layer 3 address (IP address) into a Layer 2 address (MAC address). The ARP table is populated as devices issue ARP broadcasts looking for a network device’s Layer 2 (MAC address).

AS and ASN

Within the Internet, an autonomous system (AS) is a collection of connected Internet Protocol (IP) routing prefixes under the control of one or more network operators on behalf of a single administrative entity or domain that presents a common, clearly defined routing policy to the Internet. Even though there may be multiple autonomous systems supported by an ISP, the Internet only sees the routing policy of the ISP. That ISP must have an officially registered autonomous system number (ASN). The ASN uniquely identifies each network on the Internet. There can be multiple subnets within an AS.


border gateway protocol; needed to support VPRN; connects 2 OSPF-based networks (e.g., Bell can talk to Telus’ network). BGP is used to communicate with other routers outside the border the autonomous system. Also see IGP (inside ASN).


layer 3 service; a wide bandwidth data transmission with an ability to simultaneously transport multiple signals and traffic types. The medium can be coaxial cable, optical fiber, radio or twisted pair.


types of traffic; stands for “broadcast, unknown unicast, multicast”


A CE router ( customer edge router ) is a router located on the customer premises that provides an Ethernet interface between the customer's LAN and the provider's core network. CE routers, P (provider) routers and PE (provider edge) routers are components in an MPLS (multiprotocol label switching) architecture.

Data center

Infrastructure used by service providers to host communications and networking services. These services can be loaded as cloud-based software on commercial off-the-shelf (COTS) server hardware. The applications are hosted in a data center so that they could be accessed via the cloud.The approach of using an NFV data center differs from previous deployments of specialized applications with the use of COTS hardware, rather than requiring specialized, proprietary network hardware or appliances. It has large potential for service providers, who hope to reduce operation and capital costs. By standardizing the hardware, they gain more flexibility by being able to add or subtract services as software loaded on a more economical, standardized hardware infrastructure.

Default Gateway

router for a subnetwork; allows a computer in the subnet, which can’t find the device/computer it’s trying to talk to, to reach that computer/device outside of the subnet; often seem to have an IP address ending in *.1


a network protocol that enables a server to automatically assign an IP address to a computer from a defined range of numbers (i.e., a scope) configured for a given network

Disjoint vs. non-disjoint

two paths are disjoint if they don’t have any edges in common


A type of broadband service; endpoints get their own access (e.g., Bell); opposite of Cable service


service that provides Ethernet connection; a common type of VLL; layer 2 service; can be over fiber or copper but regardless it's still an IP service


The most recent type of L2VPN, which was added to MPLS VPN portfolio is EVPN, what stands for Ethernet VPN. You may find a lot similarities between it and VPLS, though it’s completely different type of L2 VPN. The main difference is scaling. EVPN is using BGP for signaling address information (MAC and IP addresses), which significantly speeds up network convergence and reduces amount of BUM (broadcast, unknown unicast, multicast) traffic in core network. PBB is adding additional layer of scalability.


The FDB (forwarding database) table is used by a Layer 2 device (switch/bridge) to store the MAC addresses that have been learned and which ports that MAC address was learned on. Also see ARP.


A forwarding information base (FIB), also known as a forwarding table or CAM table, is most commonly used in network bridging, routing, and similar functions to find the proper interface to which the input interface should forward a packet.

Fiber network

optical network; Fiber optic (or "optical fiber") refers to the medium and the technology associated with the transmission of information as light impulses along a glass or plastic wire or fiber. Fiber optic wire carries much more information than conventional copper wire and is far less subject to electromagnetic interference.


a type of policy; determines what type of traffic can go through here and at what speed

Fixed service

IP or Optical (not mobile wireless); A fixed-line can be seen as a connection to an end customer, by means of a cable, through which a user can make phone calls or connect to the Internet. Fixed-lines are clearly separate from the mobile phone network, by which end users are connected to the network via wireless transmission technologies.


Fiber to the x (FTTX) is a generic term for any broadband network architecture using optical fiber to provide all or part of the local loop used for last mile telecommunications. As fiber optic cables are able to carry much more data than copper cables, especially over long distances, copper telephone networks built in the 20th century are being replaced by fiber. FTTX is a generalization for several configurations of fibre deployment, arranged into two groups: FTTP/FTTH/FTTB (Fiber laid all the way to the premises/home/building) and FTTC/N (fiber laid to the cabinet/node, with copper wires completing the connection).

Full mesh

when all nodes in a network can talk to all other nodes; SDP needs that conceptually, if not physically

Gateway router (GR)

router on the edge of a subnet


generic network element


also called a virtual machine manager; a program that allows multiple operating systems to share a single hardware host. Each operating system appears to have the host's processor, memory, and other resources all to itself.


Internet Enhanced Service; Service to provide Internet access; a VPN service moves data between known sites within a network whereas Internet isn’t a known site so IES doesn’t use SDPs.


An interior gateway protocol (IGP) is a type of protocol used for exchanging routing information between gateways (commonly routers) within an autonomous system (for example, a system of corporate local area networks). This routing information can then be used to route network-layer protocols like IP. It’s logical, not physical. Also see BGP (outside ASN). Doesn’t apply to Optical.


input/output module; the first number in 1/1/1; aka card


Intermediate System to Intermediate System (IS-IS) is a routing protocol designed to move information efficiently within a computer network, a group of physically connected computers or similar devices. It accomplishes this by determining the best route for datagrams through a packet-switched network. It’s the European version of OSPF.


Link aggregation; various methods for using multiple parallel network connections to increase throughput beyond the limit that one link (one connection) can achieve. For link aggregation, physical ports must reside on a single switch.Think of it like taking a bunch of small garden hoses and tying them together so you get more water outputE.g., take a 100G interface with 3 other ones and then you have a 400G interface, which can be managed as one entity rather than 4.We do this because sometimes the technology doesn’t exist that big or because it’s cheaper.


The basic implementation of MPLS; builds the LSPs based on IP routing table, making an MPLS network automatically functionally equivalent to a pure IP network; used to establish MPLS transport LSPs when traffic engineering is not required; particularly well suited for establishing a full mesh of LSPs between all of the routers on the network.


label switch path; path between two nodes in MPLS; tunnel is the highway - LSP is a lane on that highway; MPLS is the protocol - LSP is the object


mobility management entity; LTE MME is responsible for initiating paging and authentication of the mobile device.


multiprotocol label switching; data-carrying technique; short path labels rather than network addresses; avoids complex routing table lookups; ”layer 2.5” because it adds its labels between layer 2 header and layer 3 (IP packet) header. Faster than OSPF on its own because MPLS peaks at the label rather than digs through the packet for IP info; that little time saved adds up. Allows secure movement of multiple customers’ payloads on the same packet because you don’t need to look at the customer payloads in order to direct them; just need to look at the MPLS label2 versions of MPLS: RSVP (Cadillac) and LDP (basic).


multiplexed transport layer; security: protocol, TLS; sub-protocol


network address translations; internal IP address (on a subnet) have private IP addresses, but those aren’t recognized outside of that subnet, so the default gateway (router) needs to translate a private IP address to an external IP address before it sends a packet out into the Internet; allows devices to exist without having to have an unique IP address (which totally wouldn’t scale).


set of tools that have been used to provide network fault indication, performance information, fault localization, data and diagnosis functions

Operation (O) activities are undertaken to keep the network (and the services that the network provides) up and running. It includes monitoring the network and finding problems.Ideally these problems should be found before users are affected.

Administration (A) activities involve keeping track of resources in the network and how they are used. It includes all the bookkeeping that is necessary to track networking resources and the network under control.

Maintenance (M) activities are focused on facilitating repairs and upgrades — for example, when equipment must be replaced, when a router needs a patch for an operating system image, or when a new switch is added to a network. Maintenance also involves corrective and preventive measures to make the managed network run more effectively, e.g., adjusting device configuration and parameters.


Enables controller to communicate with elements. Enables network controllers to determine the path of network packets across a network of switches. The controllers are distinct from the switches. This separation of the control from the forwarding allows for more sophisticated traffic management than is feasible using access control lists (ACLs) and routing protocols. Also, OpenFlow allows switches from different vendors — often each with their own proprietary interfaces and scripting languages — to be managed remotely using a single, open protocol. The protocol's inventors consider OpenFlow an enabler of software defined networking (SDN).

OSI model

PDU is protocol data unit.

Layer 7 (Application) PDU: ftp

Layer 6 (Presentation) PDU: encryption

Layer 5 (Session) PDU: http

Layer 4 (Transport): packet delivery and sequencing; PDU = TCP/UDP

Layer 3 (Network): routers and IP addresses directing traffic; PDU = packets

Layer 2 (Data Link): switches and MAC addresses; PDU = frames

Layer 1 (Physical): physical machines providing access to media; PDU = bits


how nodes talk to each other; doesn’t really work on its own (without MPLS) except for really small networks


optical transport network; a set of Optical Network Elements (ONE) connected by optical fiber links, able to provide functionality of transport, multiplexing, switching, management, supervision and survivability of optical channels carrying client signals. OTN nodes are for distance, SRs are for power. Optical services wrap IP packets up so they can travel along the optical fibre. Think of putting people in car before you send them along the highway


policy-based routing


SDN is the concept, but how it’s done is with PCEP. Path Computation Element Protocol/Element/ClientClient is the dumb router. Its database has been extracted and put into the Element. The client will ask the element “where do I send this data?”, and the element will answer. This conversation is made possible via the PCEP. Can create LSPs. E.g., “a PCE-created LSP”.


wireless networking, mobile networking


quality of service; a type of policy; often hear colleagues pronounce this as “kwoss”


radio access network; mobile


The Cadillac implementation of MPLS; RSVP-TE is used to establish MPLS transport LSPs when there are traffic engineering requirements. It is mainly used to provide QoS and load balancing across the network core, and includes the ability to control all-optical networks.


Service Access Point; aka layer 2 access interface; it’s how services (on a router) talk to ports; SAP is logical, port is physical, but they're pretty close to the same thing

Scale out

(aka scale horizontally); means to add more nodes to a system, such as adding a new computer to a distributed software application. An example might involve scaling out from one Web server system to three. “Scale in” is the opposite: to remove nodes from a system.

Scale up

(aka scale vertically); increase network capacity by adding more resources, such as more memory or an additional CPU, to a machine; usually requires downtime while new resources are being added and has limits that are defined by hardware. E.g., When Amazon RDS customers need to scale vertically, for example, they can switch from a smaller to a bigger machine, but Amazon's largest RDS instance has only 68 GB of memory. “Scale down” is the opposite: remove resources from a machine.


software-defined network; separation of data from control plane; admins manage network services through abstraction of higher-level functionality; centralizes control plane (network plan) rather than distributes decisions to NEs; allows you to tailor traffic flow better, but it’s not required for traffic optimization.


service distribution path; aka service tunnel; layer 3. This is a Nokia-specific term, not an industry term. SDP path is not the actual physical path; it leaves out the hops. It shows which source can reach which destination as a logical connection. SDP is needed to allow routers to talk to each other (and send each other packets). One SDP per router; can transport multiple customer payloads using MPLS. SDP is to services what LSP is to network elements. It says “send this service along this path” (like LSP says “send this traffic along this tunnel path”).


Person or company who owns space on an endpoint; it’s like they’re renting space on that equipment

Service Tunnel

used to uni-directionally direct traffic from one device to another device; provisioned to use a specific encapsulation method, such as GRE or MPLS, and the services are then mapped to the service tunnel. For instance, multi-NE VLL and VPLS traffic is transmitted using uni-directional service tunnels in this way; most common type of tunnel used in 5620 SAM is a Service Distribution Point binding. Service tunnels originate on an SDP on a source NE and terminate at a destination NE. The destination NE directs packets from the service tunnel to the correct service egress interfaces (SAPs) on that device. Services that originate and terminate on the same NE do not require service tunnels, because the same NE is both the source and the destination.


A type of VPN; virtual leased line (VLL): point to point, layer 2 service; e.g., Epipe


Virtual Private LAN Service (VPLS): A type of VPN; point to multipoint, layer 2 service; like a switch; based on frame MAC addresses; a way to provide Ethernet-based multipoint to multipoint communication over IP or MPLS networks. It allows geographically dispersed sites to share an Ethernet broadcast domain by connecting sites through pseudo-wires. VPLS is better than VLL but is Ethernet only whereas VLL is for a bunch of connection types.


A type of VPN; virtual private routed network (VPRN): point to multipoint, layer 3 service; like a router; based on packet IP addresses; uses a route table, separate from the router(s).

White box

virtual network element


data modeling language; can be used to model both configuration data as well as state data of network elements. Furthermore, YANG can be used to define the format of event notifications emitted by network elements and it allows data modelers to define the signature of remote procedure calls that can be invoked on network elements via the NETCONF protocol.


A subnetwork, or subnet, is a logical, visible subdivision of an IP network.The practice of dividing a network into two or more networks is called subnetting. You can’t rightly have all of the computers in the world talking directly to each other. That would be a routing-table nightmare. So companies will split their networks off into their own subnetworks. A subnet may represent all the machines at one geographic location, in one building, or on the same local area network (LAN). Having an organization's network divided into subnets allows each subnet to be connected to the Internet with a single shared network address, which reduces the number of unique IP addresses needed. Plus, you might not want computers to be able to talk to just any old computers, so dividing them into subnets helps with security, too. Devices need to route traffic through a router in order to go out of their subnet.

Subnet mask

Subnet masks are needed to allow routers to identify the subnet address and the device address of a device, both of which are contained in the device’s IP address, both of which are needed to route traffic to and from that device. Think of the subnet mask as a secret decoder pin for the IP address. Subnet masks can be written in one of 3 ways, the most typical being "/N" added to the end of the IP address.


(optical) wavelength-division multiplexing; In fiber-optic communications WDM multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths (i.e., colors) of laser light; enables bidirectional communications over one strand of fiber, as well as multiplication of capacity.


over the top; XLEs have their own transport layer that runs on top of a real network; e.g., Netflix using Rogers to send you video instead of you watching Rogers TV - does Rogers give you good speeds for Netflix even though Netflix is a competitor?


Content Delivery Network


Internet Content Provider (like Netflix? not sure)


a protocol defined by the IETF to “install, manipulate, and delete the configuration of network devices”. NETCONF operations are realized on top of a Remote Procedure Call (RPC) layer using an XML encoding and provides a basic set of operations to edit and query configuration on a network device.


how much time it takes for a packet of data to get from one designated point to another


A type of broadband service; endpoints share access (e.g., Rogers); typically the opposite of DSL service


(utilities) A remote terminal unit (RTU) is a microprocessor-controlled electronic device that interfaces objects in the physical world to a distributed control system or SCADA (supervisory control and data acquisition) system by transmitting telemetry data to a master system, and by using messages from the master supervisory system to control connected objects. Other terms that may be used for RTU is remote telemetry unit or remote telecontrol unit.


(utilities) supervisory control and data acquisition is a control system architecture that uses computers, networked data communications and GUIs for high-level process supervisory management, but uses other peripheral devices such as RTUs to interface to the process plant or machinery.


Type of broadband telecommunications connection over traditional wire, coaxial cable, optical fibre, or microwave relay; one of a few alternatives to Ethernet; common in utilities infrastructure.


one of a few alternatives to Ethernet; a method of transmitting and receiving independent signals over a common signal path; common in utilities infrastructure


bandwidth on demand; deliver extra network capacity when it’s needed without the added complexity of running a separate network (i.e., dedicate MPLS network, which introduces complexity); BoD can disappoint if it isn’t managed effectively at the network level - need SDN strategy to help manage network resources more efficiently.


time-based bandwidth manipulation based on triggers


synchronous digital hierarchy; aka Synchronous Optical Networking (SONET); standardized protocols that transfer multiple digital bit streams synchronously over optical fiber using lasers or highly coherent light from light-emitting diodes (LEDs). At low transmission rates data can also be transferred via an electrical interface.


A metro network or MAN (metro area network) connects the Central Offices in a metro area and serves as an aggregation network between the access networks and the wide area network


virtual private network; 2 models: overlay and peer-to-peer; a VPN usually belongs to one company and has several sites interconnected acrossthe common service provider infrastructure


A peer-to-peer VPN model; in the peer-to-peer VPN model, the service provider routers carry the customer data across the network, but they also participate in the customer routing.

Overlay VPN Model

Used to be the more popular model (between it and peer-to-peer) until MPLS came along (peer-to-peer); service provider supplies a service of point-to-point links or virtual circuits across his network between the routers of the customer; aka Leased Line VPN (leased lines make dedicated connections). These point-to-point services could be of Layer 1, 2, or even 3. Examples of Layer 1 are time divisionmultiplexing (TDM), E1, E3, SONET, and SDH links. Examples of Layer 2 are virtualcircuits created by X.25, ATM, or Frame Relay.


SAP + Router; where the service traffic terminates (LSP traffic)


(mobile/wireless/radio) Session Initiation Protocol; a signalling and call set-up protocol for IP based communications, most commonly used for voice and video calling over an IP network; Vodafone Global SIP uses Voice over Internet Protocol (VoIP) technology to connect your private branch exchange (PBX) to the internet, replacing the conventional telephone trunk line.


1) NFV Orchestrator: Responsible for on-boarding of new network services (NS) and virtual network function (VNF) packages; NS lifecycle management; global resource management; validation and authorization of network functions virtualization infrastructure (NFVI) resource requests

2) Service orchestrator: basically service fulfillment / provisioning

3) OSS ochestrator: Orchestration automates simple or complex multi-system tasks on remote servers that are normally done manually


endpoint / SAP + router / NE (some combination of these)


A local area network, or LAN, provides the nodes connected to it with direct (Layer 2) access to one another. It is usually comprised of one or more Ethernet switches. Computers on different LANs talk to each other using Layer 3 (IP), via a router. A virtual LAN (VLAN) abstracts the idea of the LAN. A VLAN might comprise a subset of the ports on a single switch or subsets of ports on multiple switches. By default, systems on one VLAN don't see the traffic associated with systems on other VLANs on the same network. VLANs allow network administrators to partition their networks to match the functional and security requirements of their systems without having to run new cables or make major changes in their current network infrastructure.


Point of Presence. An Internet point of presence typically houses servers, routers, network switches, multiplexers, and other network interface equipment. It is typically located in a data center. ISPs typically have multiple PoPs. PoPs are often located at Internet exchange points and colocation centres.


Optical loss is measured in dB (decibels) while optical power loss is measured in dBm (m for milliwatt)


optical add/drop multiplexer. Type of OTN node. Used for multiplexing and routing different channels of light into or out of a single mode fiber (SMF). In addition to the original fixed version (FOADM), there are blocker or broadband (BOADM), reconfigurable (ROADM), and tunable (TOADM) alternatives. FOADM can also be COADM (customizable)


Web-scale IT is used to reference a global-class of computing — or an architectural approach — used to deliver the capabilities of large cloud service providers within an enterprise IT setting. E.g., Google, Amazon, NetFlix, Facebook. The approach is to design, build and manage data center infrastructure where capabilities go beyond scale in terms of size to include scale as it pertains to speed and agility.

lambda switching

(sometimes called photonic switching, or wavelength switching); used in optical networking to switch individual wavelengths of light onto separate paths for specific routing of information. In conjunction with technologies such as dense wavelength division multiplexing (DWDM) - which enables 80 or more separate light wavelengths to be transmitted on a single optical fiber - lambda switching enables a light path to behave like a virtual circuit; works in much the same way as traditional routing and switching. Lambda routers - which are also called wavelength routers, or optical cross-connects (OXC) - are positioned at network junction points. The lambda router takes in a single wavelength of light from a specific fiber optic strand and recombines it into another strand that is set on a different path. Lambda routers are being manufactured by a number of companies, including Ciena, Lucent, and Nortel.


optical cross-connect (see lambda switching)

Port Loopback

A loopback port is a logical container for loopback interfaces that are used to provide IP addresses that are always reachable. IP addresses that are attached to regular interfaces on physical ports will become unreachable when the port goes down. A router-id or the System IP address is another example of an always-reachable IP address.


tool used to sample IPv4, IPv6, MPLS, and Ethernet traffic data flows through a router; enables traffic sampling and analysis by ISPs and network engineers to support capacity planning, trends analysis, and characterization of workloads in a network service provider environment.