• November 06, 2006 06 Nov'06

    carrier-to-noise ratio (CNR or C/N)

    In communications, the carrier-to-noise ratio, often written CNR or C/N, is a measure of the received carrier strength relative to the strength of the received noise.  Continue Reading

  • November 06, 2006 06 Nov'06


    The term microwave refers to electromagnetic energy having a frequency higher than 1 gigahertz (billions of cycles per second), corresponding to wavelength shorter than 30 centimeters.  Continue Reading

  • November 06, 2006 06 Nov'06

    in-band signaling

    In the public switched telephone network, (PSTN), in-band signaling is the exchange of signaling (call control) information on the same channel that the telephone call itself is using.  Continue Reading

  • November 06, 2006 06 Nov'06


    Describes a telecommunication system in which information is carried in digital form on a single unmultiplexed signal channel on the transmission medium.  Continue Reading

  • November 06, 2006 06 Nov'06


    In telecommunication, a band - sometimes called a frequency band - is a specific range of frequencies in the radio frequency (RF) spectrum, which is divided among ranges from very low frequencies (vlf) to extremely high frequencies (ehf).  Continue Reading

  • November 06, 2006 06 Nov'06

    broadband voice gateway

    A broadband voice gateway is a device that allows you to make telephone calls over a high-speed Internet connection rather than through a regular telephone outlet without having to go through your computer.  Continue Reading

  • November 06, 2006 06 Nov'06

    attenuation-to-crosstalk ratio (ACR) or headroom

    Attenuation-to-crosstalk ratio (ACR), also called headroom, is the difference, expressed as a figure in decibels (dB), between the signal attenuation produced by a wire or cable transmission medium and the near-end crosstalk (NEXT).  Continue Reading

  • November 06, 2006 06 Nov'06

    ADSL (Asymmetric Digital Subscriber Line)

    Also see Fast Guide to DSL. ADSL (Asymmetric Digital Subscriber Line) is a technology for transmitting digital information at a high bandwidth on existing phone lines to homes and businesses.  Continue Reading

  • November 06, 2006 06 Nov'06

    NAC underneath the covers: Endpoint health assessments

    The main focus of NAC these days is to assess and endpoint and determine that it's "healthy" before it's allowed network access. But vendors have different methods of doing so. Here you'll find the questions you need to ask your vendor in order to ...  Continue Reading

  • November 06, 2006 06 Nov'06

    OSI: Securing the Stack, Layer 3 -- The role of ICMP

    Michael Gregg examines the security vulnerabilities of Internet Control Message Protocol (ICMP) and how to help secure OSI Layer 3, the network layer.  Continue Reading

  • November 06, 2006 06 Nov'06

    Self-study course material for CCVP certification

    Our Cisco certification expert recommends these course self-study materials for Cisco Certified Voice Professional (CCVP) exams. Use these resources and books to pass your test if you can't afford training camps.  Continue Reading

  • November 06, 2006 06 Nov'06

    System engineer vs. network administrator

    Our Cisco certifications expert, David Minutella, answers what the responsibilities of a system engineer and network administrator are and what makes the two jobs different.  Continue Reading

  • November 06, 2006 06 Nov'06

    How can you update your certifications on the job?

    In this response, our Cisco certifications expert, David Minutella, answers how one might obtain a certification on the job.  Continue Reading

  • November 06, 2006 06 Nov'06

    CCNA Video Mentor

    Cisco's CCNA Video Mentor provides you with more than two hours of personal visual instruction from best-selling author and instructor Wendell Odom to help you prepare for the CCNA certification exam. In the 12 videos presented on the CD-ROM, ...  Continue Reading

  • November 03, 2006 03 Nov'06

    Network access control: Should you implement now?

    Implementing network access control (NAC) is a big step, and deciding whether and when to start is daunting. Networking experts say the sooner the better, but before going into NAC full throttle, enterprises must first determine their motivation.  Continue Reading

  • November 02, 2006 02 Nov'06

    How IPsec provides secure communications

    IPsec provides secure site-to-site VPNs, remote access and host-to-host communication. In this tip, we peek inside the tunnel and examine how IPsec works.  Continue Reading

  • November 01, 2006 01 Nov'06

    WLAN management

    This special report from SearchNetworking.com offers managing and monitoring techniques that can help you gain control over your company's wireless devices and users.  Continue Reading

  • November 01, 2006 01 Nov'06

    QoS: The hidden cost

    Quality of Service (QoS) technology may not necessarily deliver what you've bargained for. In this edition of The Connected Edge, Loki Jorgenson explains how to examine ROI for QoS, what you can expect QoS to deliver, and when to choose another path...  Continue Reading

  • October 31, 2006 31 Oct'06

    four-way server

    A four-way server is a server that incorporates a multi-core processor for increased performance... (Continued)  Continue Reading