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Bring yourself up to speed with our introductory content.
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Bring yourself up to speed with our introductory content.
Green cloud computing quiz: Raise your energy efficiency grade
Take our green cloud computing quiz to see if you are doing enough to conserve energy. Reducing energy use helps the earth and saves you money. Continue Reading
A primer on northbound APIs: Their role in a software-defined network
This primer explores the concept of SDN northbound APIs, their key benefits, who's using them and why. Continue Reading
Floodlight primer: An OpenFlow controller
In software-defined networks, engineers use Floodlight controllers to manage physical and virtual devices -- and each traffic flow running between them. Continue Reading
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Big data initiative essentials: Adopting analytics strategies
This guide contains what you need to know for devising big data initiatives and analytics strategies. Continue Reading
VPN UTM vendor comparison: Evaluating secure remote access features
View this VPN UTM vendor comparison and understand how to manage your virtual private network infrastructure as part of a unified threat management solution. Continue Reading
‘Computer Networks' PDF: Free chapter download
Download this computer networking PDF excerpt from "Computer Networks," a book that addresses the key principles of computer networks. In Chapter 1, Foundation, learn how local and wide area networks (WANs) are now built to connect more than ...Continue Reading
Wide Area Application Services (WAAS)
Wide Area Application Services (WAAS) is a Cisco Systems technology that improves the performance of applications on a wide area network (WAN). (Continued...)Continue Reading
enterprise WAN
An enterprise WAN is a corporate network that connects geographically dispersed users areas that could be anywhere in the world.Continue Reading
MHz
The megahertz, abbreviated MHz, is a unit of alternating current (AC) or electromagnetic (EM) wave frequency equal to one million hertz (1,000,000 Hz).Continue Reading
data link layer
The Data-Link Layer is the protocol layer in a program that handles the moving of data in and out across a physical link in a network.Continue Reading
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The ultimate network monitoring software? A Splunk primer
With machine data search capability plus monitoring and management tools, Splunk is the ultimate network monitoring software.Continue Reading
OpenFlow protocol primer: Looking under the hood
We know the OpenFlow protocol can be used to abstract the network control plane from underlying physical infrastructure, but how exactly does the protocol work?Continue Reading
Microsoft Network Access Protection (NAP)
Network access protection (NAP), introduced with Windows Server 2008, is Microsoft’s approach to controlling access to a network based on a determination of each device’s health.Continue Reading
A DevOps primer for network engineers
DevOps is a movement promoting better collaboration between developers and system administrators. In this primer, we explore how it might affect networking pros.Continue Reading
Generic Routing Encapsulation (GRE)
Generic Routing Encapsulation (GRE) is a simple protocol that encapsulates packets in order to route other protocols over IP networks, as defined by RFC 2784.Continue Reading
darknet
A darknet is a routed allocation of IP address space that is not discoverable by any usual means.Continue Reading
dynamic multipoint VPN (DMVPN)
A dynamic multipoint virtual private network (DMVPN) is a secure network that exchanges data between sites without needing to pass traffic through an organization's headquarter VPN server or router.Continue Reading
context-aware network access control
Context-aware network access control (CANAC) is an approach to managing the security of a proprietary network by granting access to network resources according to contextual-based security policies.Continue Reading
Cisco Integrated Service Routers Generation 2 (ISR G2)
ISR G2 is a second generation Integrated Services Router (ISR) from Cisco Systems, Inc.Continue Reading
Wireless wide area networks: A primer on WWAN technology and uses
A wireless wide area network (WWAN) has several possibilities for uses and comes with both advantages and disadvantages. Learn about the WWAN in this primer.Continue Reading
Hotspot 2.0 primer: Another step toward Wi-Fi/cellular integration
Hotspot 2.0 and the IEEE 802.11u protocol could allow mobile device users to securely roam between Wi-Fi and cellular networks without stopping to authenticate.Continue Reading
Common AS/400 FTP questions answered
WAN engineers may have questions regarding AS/400 FTP. In this FAQ, get answers on some of the most common questions, such as how to make your AS/400 visible to an FTP server.Continue Reading
NVGRE standard primer: More VLANs and isolated tenants in the cloud
Microsoft's NVGRE standard offers competition to VMware's VXLAN standard, promising to create more VLANs that stretch across Layers 2 and 3 for multi-tenant cloud networks.Continue Reading
Storage virtualization benefits and challenges: A primer
Storage virtualization benefits abound, but along with the ability to implement dynamic storage provisioning for the cloud come some complications…including latency.Continue Reading
VXLAN standard primer: Extended VLANs, long-distance VM migration
The VXLAN standard aims to solve the long-distance VM migration dilemma by enabling extended VLANs across geographically dispersed data centers for a multi-tenant cloud network.Continue Reading
vSphere vSwitch primer: Design considerations
It takes the right kind of vSphere vSwitch design to implement segmentation for traffic manageability, security, redundancy and failover in a virtual environment.Continue Reading
link-load balancer (link balancer)
A link load balancer, also called a link balancer, is a network appliance that distributes in-bound and out-bound traffic to and from multiple Internet Service Providers (ISPs) links.Continue Reading
shortest path bridging
Shortest path bridging, or 802.1aq, is the IEEE’s specification for enabling multi-pathing in the data center. Shortest path bridging is similar conceptually to its IETF counterpart, Transparent Interconnection of Lots of Links (TRILL).Continue Reading
Transparent Interconnection of Lots of Links (TRILL)
Transparent Interconnection of Lots of Links (TRILL) is the Internet Engineering Task Force’s specification for enabling multi-pathing in the data center. The protocol is intended to replace the spanning tree protocol.Continue Reading
mean opinion score (MOS)
In voice communications, particularly Internet telephony, the mean opinion score (MOS) provides a numerical measure of the quality of human speech at the destination end of the circuit.Continue Reading
Virtual branch office in a box (vBOB) devices may replace hardware
As you introduce your enterprise WAN to virtualization, a virtual branch office in a box (vBOB) may take shape in remote offices. Learn in this tip how BOBs are being reinvented.Continue Reading
OSGi (Open Service Gateway Initiative)
OSGi (Open Service Gateway Initiative) is Java framework for developing and deploying modular software programs and libraries.Continue Reading
loose coupling
Loose coupling is a method of interconnecting the components in a system or network so that those components, also called elements, depend on each other to the least extent practicable... (Continued)Continue Reading
Evolved Packet Core (EPC)
Evolved Packet Core (EPC) is a flat architecture that provides a converged voice and data networking framework to connect users on a Long-Term Evolutio (LTE) network.Continue Reading
Layer 3 VPN architectures
This guide serves as an introduction to Layer 3 VPN architectures. As you consider different virtual private network types for your enterprise WAN, such as MPLS, IPsec, SSL and remote, be mindful of the traffic you want to transmit (data, voice, etc...Continue Reading
patch antenna
A patch antenna is a wafer-like directional antenna suitable for covering single-floor small offices, small stores and other indoor locations where access points cannot be placed centrally.Continue Reading
AARP (AppleTalk Address Resolution Protocol)
AARP (AppleTalk Address Resolution Protocol) is a way to map between the physical hardware addresses of computers, such as those known to an Ethernet or token ring local area network, and their temporarily assigned AppleTalk network addresses.Continue Reading
AAUI (Apple attachment unit interface)
An AAUI (Apple attachment unit interface) is the 14- or 15-pin port or connection interface on earlier models of Macintosh computers that allowed it to be connected by a short interface cable (or "transceiver") to an Ethernet cable.Continue Reading
average bouncing busy hour (ABBH)
In designing and assessing telephone networks, one approach is to measure the average bouncing busy hour (ABBH) traffic in various network trunks or trunk groups of the network.Continue Reading
modem lights (AA)
This page provides a description of the abbreviations and meanings of each of the lights that describe the "handshaking" between a computer modem and the UART chip in a computer.Continue Reading
Multichannel Multipoint Distribution Service (MMDS)
Multichannel Multipoint Distribution Service (MMDS) is a broadcasting and communications service that operates in the ultra-high-frequency (UHF) portion of the radio spectrum between 2.1 and 2.7 GHz.Continue Reading
plain old telephone service (POTS)
POTS is a term sometimes used in discussion of new telephone technologies in which the question of whether and how existing voice transmission for ordinary phone communication can be accommodated.Continue Reading
software-defined radio (SDR)
Software-defined radio (SDR), sometimes shortened to software radio (SR), refers to wireless communication in which the transmitter modulation is generated or defined by a computer, and the receiver uses a computer to recover the signal intelligence.Continue Reading
WiMAX (Worldwide Interoperability for Microwave Access)
WiMAX is a wireless industry coalition whose members organized to advance IEEE 802.16 standards for broadband wireless access (BWA) networks...(Continued)Continue Reading
Classes of MPLS services: Find the best MPLS/VPN service for your WAN
Despite the many names given to MPLS/VPNs by marketers, there are only three classes of MPLS-based VPN services with very distinct characteristics. If you’re able to map their service descriptions into one of these classes, you’ll immediately ...Continue Reading
fiber to the x (FTTx)
Fiber to the x (FTTx) is a collective term for various optical fiber delivery topologies that are categorized according to where the fiber terminatesContinue Reading
802.11s
802.11s is a proposed amendment to the 802.11 wireless networking standards that will provide a vendor-neutral way to build wireless mesh networks over wireless LAN (WLAN) products.Continue Reading
I/O Virtualization and Converged I/O: Understanding the basics
I/O virtualization and converged I/O are crucial to enabling converged data center networks and avoiding the bottlenecking that arises in virtualized environments. In this primer, learn about I/O virtualization appliances and software, as well as ...Continue Reading
Virtualization networking guide: Managing virtualization
Networking professionals must understand how server virtualization affects the network. This virtualization networking guide examines capacity planning for virtual server networking, managing virtual networks through distributed virtual switching, ...Continue Reading
MPLS VPN basics
In this review of MPLS VPN basics, discover the differences between MPLS VPN and traditional virtual private networks, as well as the advantages and disadvantages of this newer service provider offering.Continue Reading
What's the value of ITIL foundation certification?
The ITIL foundation certification sets the baseline for understanding the move to an IT service management model. Whether it is required by your organization, for personal resume enhancement, or even to move into another type of IT role, an ITIL ...Continue Reading
Primer: Multi-tenant network for the private cloud
The push for private cloud computing networks is creating new security and management challenges for network managers. The first step is to build a multi-tenant network to isolate applications and data; next come application-aware networks.Continue Reading
How to apply network virtualization to a wide area network (WAN)
How can you apply network virtualization technology to an enterprise wide area network (WAN)? Allocating bandwidth and improving network management and performance are just a sampling of what WAN managers can do better. In this primer, discover ...Continue Reading
throttled data transfer
Throttled data transfer, also known as data transfer throttling or lean data transfer, is the deliberate regulation of the data transfer rate in a communications system... (Continued)Continue Reading
WAN bandwidth optimization tools and techniques
WAN bandwidth optimization tools and techniques are explained in this primer on getting the most out of your business wide area network links. This introduction to WAN technologies discusses methods and products that accelerate traffic so that your ...Continue Reading
Wide Area Ethernet (WAE)
Wide Area Ethernet (WAE) or Ethernet WAN (also sometimes referred to as fiber or LAN extension service ) is a network carrier service that delivers high-speed wide area network (WAN) connectivity, utilizing Ethernet as the connection method. ...Continue Reading
CCNA quiz: Test your skills from routing configuration to VLANs
In this CCNA quiz, you can test yourself on a number of skills found in the CCNA certification study guide, ranging from Cisco IOS router configuration to setting up VLANs with Cisco switches and monitoring spanning tree protocol operation.Continue Reading
Wireshark filter tutorial: A Wireshark guide from Laura Chappell
This Wireshark guide from Laura Chappell examines the open source network monitoring tool and its many uses. Use this Wireshark filter tutorial to find out what the network analyzer can do for your network.Continue Reading
Smart grid tutorial: What IT managers should know
This smart grid tutorial explains what enterprise IT managers should know about the technology and how it will be applied to your business's wide area network (WAN).Continue Reading
100 Gigabit Ethernet (100GbE)
100 Gigabit Ethernet (100GbE) is a standard in development that will enable the transfer of Ethernet frames at 100 gigabits per second (gp/s). The 100GbE standard is for core switching. A 40GbE standard, in development simultaneously, is designed ...Continue Reading
Internet Group Management Protocol (IGMP)
The Internet Group Management Protocol (IGMP) is an Internet protocol that provides a way for an Internet computer to report its multicast group membership to adjacent routers.Continue Reading
How do I...choose a VPN for my small business?
A virtual private network (VPN)is a way to use a public telecommunication infrastructure, such as the Internet,to provide remote offices or individual users with secure access to their organization's network.Continue Reading
device relationship management (DRM)
Device relationship management (DRM) is enterprise software that enables the monitoring, managing, and servicing of intelligent devices over the Internet.Continue Reading
Web SSL VPN introduction
This Web SSL VPN introduction answers the question "What is a Web SSL VPN?" and explains SSL VPN advantages in remote access environments. Understand how they evolved from their lesser IPsec VPN counterparts, how they protect against hackers, how ...Continue Reading
wireless WAN (Wireless Wide Area Network)
A wireless WAN is a wide area network in which separate areas of coverage or cells are connected wirelessly to provide service to a large geographic area.Continue Reading
What is a sensor network?
This technology overview answers the question "What is a sensor network?" It defines the term and explains why network managers need to know about it in the enterprise space, especially IT professionals dealing with wide areaContinue Reading
Using LAN edge switch security features for network defense-in-depth
Enterprises are turning their focus to the largely unused LAN edge switch security features that can enable the use of ACLs and VLANs for port management and traffic monitoring. LAN edge switches also support network access authentication and can be...Continue Reading
Types of cloud computing services WAN managers should consider
WAN managers can benefit greatly from understanding the different types of cloud computing services available to them. Understand how SaaS, PaaS, IaaS, security, network, systems, and project planning services can be used to benefit your enterprise ...Continue Reading
frequency-shift keying (FSK)
Frequency-shift keying (FSK) is a method of transmitting digital signals.Continue Reading
frequency modulation (FM)
Also see modulation and frequency-shift keying (FSK).Continue Reading
fiber to the curb (FTTC)
Fiber to the curb (FTTC) refers to the installation and use of optical fiber cable directly to the curbs near homes or any business environment as a replacement for "plain old telephone service" (POTS).Continue Reading
Digital Powerline (DPL)
Digital Powerline (DPL) technology provides the transmission of data to users over the same lines that bring electric power to homes and businesses.Continue Reading
cyclic redundancy checking
Cyclic redundancy checking is a method of checking for errors in data that has been transmitted on a communications link.Continue Reading
customer premises equipment (CPE)
Customer premises equipment (CPE) is telephone or other service provider equipment that is located on the customer's premises (physical location) rather than on the provider's premises or in between.Continue Reading
Broadband over Power Line (BPL)
Broadband over Power Line (BPL) is a technology that allows Internet data to be transmitted over utility power lines.Continue Reading
baud
Baud was the prevalent measure for data transmission speed until replaced by a more accurate term, bps (bits per second).Continue Reading
bits per second (bps or bit/sec)
In data communications, bits per second (abbreviated bps or bit/sec) is a common measure of data speed for computer modems and transmission carriers.Continue Reading
Cloud computing network primer
Cloud computing network architecture is moving toward a flat, leaf-spine topology, enabling reduced latency and balancing bandwidth, providing any-to-any connectivity within and between servers. Learn more in this primer.Continue Reading
VLAN guide for networking professionals
Virtual LANs (VLANs) are LANs with definitions that map workstations based on anything except for geographic location. In this VLAN guide, you will learn about VLANs as they relate to server virtualization and WLANs and find VLAN configuration tips ...Continue Reading
Evaluating Citrix Branch Repeater for WAN optimization
Citrix's product for WAN optimization is the Citrix Branch Repeater. This family of products integrates network optimization with application, desktop and server virtualization.Continue Reading
Evaluating Blue Coat Systems' WAN optimization
Blue Coat Systems distinguishes itself as a WAN optimization vendor with strengths in security and application visibility. Learn important facts about Blue Coat's ProxySG and PacketShaper products.Continue Reading
Evaluating Silver Peak Systems for WAN optimization
Silver Peak Systems' WAN optimization product line addresses problems typically seen in the data center, including accelerating data backup, server and storage centralization, and real-time collaboration and virtual desktop infrastructure (VDI).Continue Reading
Evaluating Ipanema Technologies' WAN optimization
Ipanema Technologies provides WAN optimization to system integrators, VARs, and service providers. It offers extensive performance management in addition to acceleration and optimization technology.Continue Reading
WAN optimization vendors: Comparison methodology and snapshot
We polled the major WAN optimization vendors for product information and compiled it to help you make a vendor comparison. Here we list the main differences between WOC providers, in brief.Continue Reading
Evaluating Expand Networks accelerators for WAN optimization
Expand Networks' accelerators help WAN optimization by supporting branch office server consolidation, server-based computing and virtualization technologies, as well as low-bandwidth, high-latency links.Continue Reading
Evaluating Riverbed Steelhead WAN optimization
Riverbed Steelhead appliances for WAN optimization are focused on specific enterprise applications -- such as rich media, thin clients, Web apps and disaster recovery -- scalability and ease of installation.Continue Reading
Evaluating Cisco WAAS WAN optimization
Cisco WAAS is a family of WAN optimization products that integrate well into the network environment and offers broad application support through Cisco's partnerships.Continue Reading
Regional Internet Registry (RIR)
A Regional Internet Registry (RIR) is a not-for-profit organization that oversees Internet Protocol (IP) address space and the Autonomous System (AS) numbers within a specific geographical region. Each RIR is tasked with creating local policy for ...Continue Reading
Bandwidth measurement and management guide
Today's enterprise applications are demanding more and more network bandwidth. How do you ensure you have enough bandwidth and manage it well? Find out with the resources in our bandwidth measurement and management guide.Continue Reading
IP network design guide: Managing an IP-based network
Network design underlies the performance of your enterprise IP network. This four part guide by Cormac Long offers you a comprehensive roadmap to designing IP-based networks, from the basic principles involved to the more complex finishing touches.Continue Reading
logical network
A logical network is one that appears to the user as a single, separate entity although it might in fact be either just a part of a larger network or an entity connecting multiple networks. A logical network is defined by its IP addressing scheme.Continue Reading
WAN accelerator
A WAN accelerator is an appliance that improves the end user's experience on a wide area network (WAN).Continue Reading
chatty protocol
A chatty protocol is an application or routing protocol that requires a client or server to wait for an acknowledgement before it can transmit again.Continue Reading
Packet Order Correction (POC)
Packet Order Correction (POC) is a technique for dealing with out-of-order packet delivery.Continue Reading
transparent addressing
On a wide area network (WAN), transparent addressing is a method of network addressing in which all intermediate node addresses are spoofed, so the client and server see each other's addresses and port configurations as if there were no intermediate...Continue Reading
Port Address Translation (PAT)
Port Address Translation (PAT), is an extension to network address translation (NAT) that permits multiple devices on a local area network (LAN) to be mapped to a single public IP address. The goal of PAT is to conserve IP addresses.Continue Reading
wireless mesh network (WMN)
A wireless mesh network (WMN) is a mesh network created through the connection of wireless access points installed at each network user's locale.Continue Reading
WAN clustering (geoclustering, high-availability clustering or remote clustering)
WAN clustering, also called geoclustering, high-availability clustering or remote clustering, is the use of multiple redundant computing resources located in different geographical locations to form what appears to be a single highly-available ...Continue Reading
stateful inspection
Stateful inspection is a firewall technology that monitors the state of active connections and uses this information to determine which network packets to allow through the firewall. Stateful inspection is also known as dynamic packet filtering.Continue Reading
green networking
Green networking is the practice of selecting energy-efficient networking technologies and products, and minimizing resource use whenever possible.Continue Reading